SUPERIOR COURT OF THE DISTRICT OF COLUMBIA
CRIMINAL DIVISION - FELONY BRANCH
UNITED STATES OF AMERICA,
v.
RAYMOND ANTHONY JENKINS.
Criminal No. F-320-00
Judge Broderick
Trial Date 10/12/04
_______________________________/
GOVERNMENT'S SUPERSEDING OPPOSITION TO DEFENDANT’S
MOTIONS IN LIMINE TO PRECLUDE INTRODUCTION OF DNA EVIDENCE
KENNETH L. WAINSTEIN,
United States Attorney.
MICHAEL AMBROSINO, D.C. BAR #451549
VALINDA JONES, D.C. BAR #398464,
Assistant United States Attorneys.
555 Fourth Street, N.W.
Room 9816
Washington, D.C. 20001
(202) 514-0504
INDEX
Page
INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
BACKGROUND OF THE CASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
DNA EVIDENCE TO BE OFFERED AT TRIAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
ARGUMENT
I.
Defendant’s Supplemental Motion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
II.
Defendant’s Cold-Hit Motion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
III.
The law in the District of Columbia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
IV.
DNA analysis by the PCR/STR method is universally
accepted
in the relevant scientific community and the courts
V.
A.
Background of DNA analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
B.
The PCR process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
C.
The current generation of PCR-based analysis: STRs
1.
Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
2.
The STR method is generally accepted. . . . . . . . . . . . . . . . .30
The defendant’s arguments against the DNA typing methods
in this case go to weight of the evidence, not its admissibility. . . . . . . . . .
.37
A.
The Court does not have to find that the tools used
to apply the PCR/STR technique are generally accepted;
even if it did, the kits and instrument used in these
cases are generally accepted. . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
1.
2.
No inquiry is required under Frye. . . . . . . . . . . . . . . . . . . . . . 38
The kits are generally accepted. . . . . . . . . . . . . . . . . . . . . . .41
Adherence to the TWGDAM guidelines
is not required for general acceptance. . . . . . . . . . . 42
b.
The Profiler Plus/Cofiler/310 Analyzer
system has been proven reliable by laboratory
validation studies, published peer-reviewed
research, and actual experience. . . . . . . . . . . . . . . .46
B.
The general acceptance of DNA typing methods
does not turn on whether the laboratory applying
those methods is subject to blind
or open proficiency testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
C.
The general acceptance of a scientific method does
not turn on whether the quality assurance standards and
protocols for that method are also generally accepted,
or whether the laboratory applying that method has
followed accepted protocols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Allegations of interpretive errors in individual cases go to
weight, not admissibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
D.
VI.
a.
1.
The Frye test does not require proof of adherence
to correct procedures in each particular case. . . . . . . . . . . .61
2.
The defendant’s allegation that the methodology
applied in this particular case is unreliable
does not demonstrate deficiencies in
the underlying scientific methods. . . . . . . . . . . . . . . . . . . . .64
The procedures by which the FBI determines statistical
match probabilities, which include use of the product
rule, are generally accepted by the relevant scientific community. . . . . . .67
A.
Although not admissible twelve years ago, probability
calculations based on the product rule are now admissible
because the scientific consensus has changed. . . . . . . . . . . . . . . .70
B.
The FBI calculates probability statistics for
single-source evidence samples by methods found
acceptable by the National Research Council. . . . . . . . . . . . . . . . 77
The FBI’s method for calculating combined
probabilities for mixed sample DNA profiles
is generally accepted. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
C.
D.
VII.
Inclusion of error rates in probability statistics is
unacceptable in the relevant scientific community, and
therefore not required under Frye. . . . . . . . . . . . . . . . . . . . . . . . . .91
The fact that the defendant was first identified by a
“cold-hit” on a DNA database does not affect the
admissibility of the DNA evidence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94
A.
B.
The Random Match Probability (RMP) is
always relevant and admissible to show
the rarity of a DNA profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
The approaches cited by defendant are generally
accepted methods of answering questions other
than the rarity of a DNA profile, but not all are admissible
under legal evidentiary standards. . . . . . . . . . . . . . . . . . . . . . . . . 103
1.
The NRC I Approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
2.
3.
The NRC II Approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
The Donnelly and Friedman Approach. . . . . . . . . . . . . . . .116
iv
C.
The failure to incorporate estimates of error rates into
the probability statistics does not preclude admission
of the DNA evidence in a cold hit case. . . . . . . . . . . . . . . . . . . .
D.
The probative value of the DNA evidence
in a cold-hit case is not outweighed by prejudicial effect. . . . .
. . .121
E.
The chain of custody for defendant’s
DNA sample in the Virginia offender database
is irrelevant to this case. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 120
122
VIII.
The Court does not need to hold an evidentiary
hearing on all of the defendant’s claims. . . . . . . . . . . . . . . . . . . . . . .
. 123
v
SUPERIOR COURT OF THE DISTRICT OF COLUMBIA
CRIMINAL DIVISION - FELONY BRANCH
UNITED STATES OF AMERICA
Criminal No. F-320-00
v.
Judge Broderick
Trial Date: 10-12-04
RAYMOND ANTHONY JENKINS.
/
GOVERNMENT'S SUPERCEDING OPPOSITION TO DEFENDANT’S
MOTIONS IN LIMINE TO PRECLUDE INTRODUCTION OF DNA EVIDENCE
INTRODUCTION
On March 12, 2001, defendant filed a 112 page motion in limine to
preclude the introduction of DNA evidence (hereinafter “Defendant’s Original
Motion”). The United States filed a 91 page opposition to that motion on June
23, 2001. Almost three years later, and on the eve of the last trial date,
defendant filed two additional DNA motions entitled “Supplemental Motion To
Exclude Nuclear DNA ‘Match’ Evidence, DNA Expert Testimony, and ‘Random
Match Probability’ Calculation” (hereinafter “Defendant’s Supplemental
Motion”) and “Motion To Exclude DNA ‘Inclusion’ Evidence, Expert Testimony,
And Frequency Statistics Because There Is No General Acceptance As To The
Statistical methods Of Interpretation Of DNA Evidence That Derives From A ‘Cold
Hit’ In A DNA Database, With Points And Authorities In Support” (hereinafter
“Defendant’s Cold-Hit Motion”). Defendant’s challenges to the DNA evidence
can be divided into two general categories: (1) the method by which the FBI
amplifies, analyzes, and interprets DNA profiles; and (2) the method by which
the FBI computes the statistical significance of DNA matches. The Defendant’s
Original Motion discusses both of these issues. The Defendant’s Supplemental
Motion merely repeats the same issues set forth in Defendant’s Original Motion,
all of which have been resolved in favor of the government by the Honorable
Robert I. Richter (in United States v. Orlando Roberts, F-771-01 and United States
v. David Veney, F-3986-00)1/, the Honorable Ann O’Reagan Keary (in United
States v. Henry Thompson, F-6540-02)2/, and the Honorable Judith E. Retchin (in
United States v. Sidney Smith), F-9156-98.3/ Defendant’s Cold-Hit Motion purports
to raise a new statistical issue resulting from the fact that the defendant was first
identified through a search of a DNA offender database. As discussed at length
below, the defendant’s motions are without merit. Due to the passage of time,
and in the interests of efficiency, the United States, by and through its attorney,
the United States Attorney for the District of Columbia, hereby files this
1/
Judge Richter’s ruling is attached hereto as Appendix II, Tab X.
2/
Judge Keary’s oral ruling of June 17, 2003, is attached hereto as
Appendix II, Tab Y.
3/
Judge Retchin’s oral ruling of October 2001, is attached hereto
as Appendix I, Tab S. In each of these cases, the judges resolved
the issues without a hearing. In the Orlando Roberts/David Veney
and Henry Thompson cases, the defense specifically requested a
Frye hearing. In the Sidney Smith case, the parties adopted the
original DNA pleadings in this case and agreed to have the court
resolve the DNA admissibility issue based upon the Jenkins
2
superceding pleading along with superceding appendices respectfully
opposing all three of defendant’s DNA pleadings. As grounds for this
superceding opposition, the United States relies on the following points and
authorities, and such other points and authorities as may be adduced at any
hearing on this matter:
BACKGROUND OF THE CASE
The government expects the evidence to show that, on Friday June 4,
1999, at approximately 4:15 p.m., Metropolitan Police Department (“MPD”)
officers were called to the home of Dennis Dolinger at 1516 Potomac Avenue,
S.E., Washington, D.C., where they discovered Mr. Dolinger’s body in the
basement. He had been stabbed many times in the head. The District’s
Medical Examiner ruled the death a homicide.
Based on the condition of the crime scene, it appeared that an assailant
had been injured during the assault. Blood stains were found on clothing and
other surfaces in the basement where the decedent’s body was discovered,
there were traces of blood leading from the basement to the first and second
floors of the house, and outside to the front walkway and sidewalk, and bloody
clothing was found in a room on the second floor. The police also determined
pleadings.
3
that, among other things, a diamond ring, a gold chain, and possibly some cash
were missing from the decedent’s house.
The MPD soon learned that a man identified as Stephen Watson made
several purchases using the decedent’s credit card within 24 hours of the
murder. After further investigation revealed that Watson had other items
belonging to the decedent in his possession, and that he had been seen in the
vicinity of decedent’s house on the day of the murder, Watson was arrested on
a warrant for Felony Murder While Armed.
MPD detectives sent evidence samples taken from the murder scene
(“evidence samples”) to the Federal Bureau of Investigation (“FBI”) for forensic
analysis. After conducting an analysis of DNA extracted from blood found in
several of the evidence samples and DNA from blood samples taken from
Watson, the decedent, and other individuals (“known samples”), the FBI forensic
laboratory reported on November 8, 1999, that the blood of the decedent was
contained in a number of the evidence samples, that Stephen Watson could be
excluded as the contributor of the blood from any of the tested crime scene
samples, and that a single individual, whose identity was unknown at that time,
appeared to be the contributor of the blood in a significant number of the
evidence samples.
On November 16, 1999, the Virginia Division of Forensic Science ("the
Division") was asked to assist in the investigation. The Division was sent a copy of
4
the FBI’s report, which contained the DNA profile of the unknown contributor of
the blood evidence from the crime scene. Using a portion of this profile4/, the
Division searched the Virginia DNA Databank and concluded that the profile
was consistent with the DNA profile of one “Robert P. Garrett.” Law
enforcement records revealed that the name “Robert P. Garrett” was an alias
used by the defendant Raymond Anthony Jenkins, and that Jenkins’s personal
information matched the personal information of the individual known to Virginia
authorities as Robert P. Garrett.
As a result, MPD obtained a search warrant for a sample of defendant’s
blood, which it acquired on November 23, 1999. The FBI performed a DNA
analysis of defendant’s known blood sample using the same methods and tools
it had used to analyze the DNA in the samples from the crime scene. A
comparison of defendant’s DNA profile with the DNA profile of evidence
samples revealed that defendant’s DNA profile matched the profiles of blood
from several locations at the Dolinger crime scene. In particular, the FBI
identified defendant’s blood on: (a) a pair of jeans found in the basement near
4/
As discussed in greater detail infra, the DNA profiles were
developed by the FBI by typing information at certain locations of
the DNA known as “loci.” The DNA profile developed by the FBI of
the unknown contributor consisted of a 13 locus profile. However,
at the time the database search was performed back in 1999, the
Virginia Division of Forensic Science catalogued offenders in its
database system utilizing an 8-locus DNA profile.
Thus, in
searching the Virginia database, the Virginia Division of Forensic
Science only utilized a portion of the profile developed by the
FBI, i.e., 8 out of the 13 loci.
5
the decedent; (b) a shirt found in the upstairs exercise room; (c) a towel on the
basement bathroom rack; (d) the sink stopper in the sink of the same bathroom;
and (e) a railing between the first and second floors of the residence. The FBI
had previously determined that the decedent’s blood was also on the jeans
and shirt that contained defendant’s blood.
After identifying defendant as a suspect, the police also received
information from a witness who reported that, the day after the murder, the
witness saw the defendant in possession of a diamond ring, gold chains, and
over $1,000 in cash. The defendant also appeared to have numerous scratches
or cuts to his face.
Defendant was arrested on January 13, 2000, and charged with firstdegree murder. Throughout the course of these proceedings, the government
furnished defendant’s counsel with discovery materials relevant to the DNA
profile evidence in this case. These materials included, among other items, MPD
crime-scene examination reports, MPD evidence reports, correspondence with
the Virginia Department of Criminal Justice Services regarding that office’s initial
identification of defendant through the Commonwealth’s DNA profile database,
reports of the FBI tests of the blood-sample evidence, FBI DNA laboratory
protocols for performance of the DNA tests in this case, and the curriculum vitae
for the FBI scientist who oversaw the testing. In fact, in an effort to
accommodate the defense, the United States has gone well beyond the scope
6
of Rule 16 by allowing the defendant’s counsel to conduct full interviews of FBI
employees, including the DNA analyst, the hair and fiber analyst, and the
fingerprint analyst.5/
DNA EVIDENCE TO BE OFFERED AT TRIAL
5/
Defendant’s assertion that it may be necessary to supplement the
various DNA pleadings with additional information because discovery
in this case is allegedly incomplete (Defendant’s Supplemental
Motion at 23) is utterly groundless.
The United States has
fulfilled its obligations under Rule 16. Moreover, as noted above,
the Unite States has gone beyond its obligations under Rule 16 by
permitting defendant’s attorneys to interview a number of forensic
witnesses. Hence, the Court should not permit any further eleventh
hour pleadings by the defense.
7
The FBI laboratory identified and compared the DNA found in the crime
scene evidence samples with the DNA found in defendant’s and decedent’s
blood samples using two complementary scientific methods: first, samples of
DNA were amplified, or copied at specifically-targeted locations, using a
technique called polymerase chain reaction (“PCR”); and, second, certain
segments of DNA (called short tandem repeats, or “STRs”) were identified, or
“typed,” compared to each other, and found to match either the defendant or
the decedent.6/ To facilitate its lab analysis, the FBI used two commercial kits
manufactured by the Perkin Elmer Corporation (“Perkin Elmer”),7/ called
AmpFLSTR Profiler Plus (“Profiler Plus”) and AmpFLSTR Cofiler (“Cofiler”). These
kits enable FBI DNA analysts to locate, mark, and amplify a total of 13 separate
STR sites on the DNA samples under study. The analysts then used a machine
called a 310 Prism Genetic Analyzer (“310 Analyzer”) to separate the STRs found
at each of the targeted 13 sites by the method of laser fluorescent capillary
electrophoresis. Each of the 13 STR sites found in each sample of DNA was
identified, or typed, according to the number of STRs found at that site.
Together, the types of STRs found at all 13 sites constitute the DNA profile for
each sample of DNA. After finding that defendant’s or decedent’s DNA profile
6/
These methods will be described in greater detail infra.
7/
The company is now called Applied Biosystems. Because most of
the cases addressing the company’s kits use the company’s former
name, we do the same in this brief.
8
was identical to the DNA profile from the evidence samples, the FBI calculated
the statistical probability that the same profile might be found at random in a
population of unrelated individuals. These calculations were made using
statistical methods that included a procedure known as the product rule.
The United States intends to offer expert testimony at trial pertaining to items
of evidence that were the subject of the above analysis. There are two types of
DNA evidence that were recovered from the crime scene: (1) “sole source
samples” that comprised blood from a single individual; and (2) “mixture samples”
that contained blood from two or more individuals. With respect to the sole source
samples, the government’s DNA expert will testify that the DNA profile of blood
developed from thirteen sole source evidence samples is identical to the
defendant’s DNA profile, and that the DNA profile of blood developed from twenty
two sole source evidence samples is identical to the decedent’s DNA profile.
Hence, there are a total of thirty five sole source samples. In all but two of these
sole source samples, the FBI was able to amplify the DNA profile at 13 loci. In two of
the sole source samples (matching the defendant’s DNA profile), the FBI was able
to amplify the samples at only 8 loci.
The statistical calculations of the various sole source samples will vary
depending upon the specific allelles present at each locus. Instead of stating a
single statistic, the statistical calculations for each sole source sample will be broken
down into four categories representing separate populations, i.e. African American,
9
Caucasian, South Eastern Hispanic, and South Western Hispanic. This is easily
illustrated by a single piece of evidence taken from a blood stain on a shirt
recovered from the crime scene. The blood stain was determined to be a sole
source evidence sample that matched defendant’s DNA profile at 13 loci. The
statistical calculation for this evidence sample is stated as follows:
POPULATION
RARITY OF DNA PROFILE
AFRICAN
AMERICAN
1 / 26,000,000,000,000,000,000
CAUCASIAN
1 / 870, 000,000,000,000,000,000
SOUTH EASTERN
HISPANIC
1 / 1,000,000,000,000,000,000,000
SOUTH WESTERN
HISPANIC
1 / 4,000,000,000,000,000,000,000
When the probability calculation results in an estimate that is more than one in 260
billion, it will be reported in the above format. However, when the probability
calculation results in an estimate that is more rare than one in 260 billion, the
government’s expert will opine that either the defendant or the decedent (where
appropriate) was the source of the detected DNA, to a reasonable degree of
scientific certainty.
The government’s DNA expert will also discuss mixture samples. In some of
the mixture samples, the FBI analyst will testify that the major contributor of sample is
defendant and decedent can not be excluded as an additional contributor.
Conversely, in other mixtures, the FBI analyst will testify that the major contributor is
10
the decedent and the defendant can not be excluded as an additional
contributor. Finally, in one mixture, the FBI analyst will testify that the decedent and
defendant are both contributors. In all but one of the mixture calculations, the FBI
analyst was able to discern a major contributor profile at 13 loci in the mixture and
calculate the statistical significance of the profile as if a single source. In one
instance, however, the FBI analyst calculated the match probabilities as though he
had no information about possible contributors. In that instance, he used a formula
known as the combined probability of inclusion.8/
ARGUMENT
I.
Defendant’s Supplemental Motion
In Defendant’s Supplemental Motion, defendant moves under Frye v. United
States, 54 U.S. App. D.C. 46, 293 F. 1013 (1923), to exclude the DNA evidence on the
grounds that (1) the collection, analysis, interpretation of nuclear DNA under PCR
amplification of short tandem repeats is not generally accepted within the relevant
scientific community; (2) the Profiler Plus and Cofiler kits used to apply the PCR/STR
methods, and the 310 Analyzer used to identify the STRs at the 13 loci, are not
generally accepted; (3) the FBI’s method for calculating the probabilities of a
random match at 13 loci is not generally accepted; and (4) the FBI’s alleged failure
to follow proper procedures, and its failure to conduct blind proficiency tests, make
8/
This formula is discussed at length, infra.
11
the results of the its DNA testing scientifically unreliable (Defendant’s Supplemental
Motion at 1-2).
The defendant’s supplemental motion should be denied. As the defendant
has noted, the arguments he raises include a “significant amount of material” that
has been provided to other judges in D.C. Superior Court considering similar
challenges (Defendant’s Supplemental Motion at 3-4). In fact, the defendant has
submitted to this Court the same arguments and supporting materials that were
submitted to the Honorable Robert I. Richter in the consolidated Frye proceedings
involving United States v. Orlando Roberts, F-771-01, and United States v. David
Veney, F-3986-00, and to the Honorable Ann O’Regan Keary
in the Frye
proceedings in United States v. Henry Thompson, F-6540-02. In addition, Judge
Richter denied the Roberts and Veney motions in a 20-page written order, a copy
of which is included in the government’s Appendix II, Tab X. Judge Keary, primarily
for the reasons given by Judge Richter, also denied the motion to exclude DNA
evidence in the Thompson case. A copy of Judge Keary’s oral ruling of June 17,
2003, is included for the record in Government’s Appendix II, Tab Y.
These issues were also raised before the Honorable Judith E. Retchin in United
States v. Sidney Smith, F-9156-98, in which the parties adopted the original DNA
pleadings filed in this case and requested that the Court issue a ruling based upon
those pleadings. Based upon the original DNA pleadings in this case, Judge
Retchin denied the defendant’s motion to exclude DNA evidence. A copy of
12
Judge Retchin’s oral ruling of October 23, 2001 is included for the record in
Government’s Appendix I, Tab S. Likewise, the government will put forth in this
opposition arguments that are the same or consistent with the previous oppositions
filed, and provide to this court the same exhibits.
The defendant has requested that this court not look to a ruling issued by
Judge Richter in the Roberts and Veney cases for guidance in this case
(Defendant’s Supplemental Motion at 4). The defendant finds fault in the fact that
Judge Richter did not
conduct an adversarial hearing, but, as the court will see upon review of this
opposition, such a hearing is not necessary.9/
9/
The defendant further argues that “Judge Richter also engaged
in impermissible burden-shifting” concerning the issue of
independent defense testing of the evidence (Defendant’s
Supplemental Motion at 4). That argument also must fail. After
finding that the FBI’s methods for analyzing DNA and formulas for
calculating random match probability were generally accepted, Judge
Richter opined that “The extent to which a defendant could
theoretically be prejudiced by the possibility of a false positive
result is mitigated by the fact that defendants are now
legislatively given the right to independent testing under the
IPA.”
(United States v. Orlando Roberts, F-771-01, and United
States of America v. David Veney, F-3986-00, Order by Judge Robert
Richter dated March 25, 2003 at 19 (“Roberts/Veney Order”). Judge
Richter so recognized independent testing to be a control on false
positives in the context of admissibility (see Id.). Judge Richter
is recognizing a safeguard put into place by the D.C. City Council
that responds to an argument that the defense made concerning a
fear of false positives. Because it concerns the admissibility of
evidence, this order does not shift the burden to the defendants.
13
The government notes that there are no new arguments raised in
Defendant’s Supplemental Motion. Judge Richter’s, Judge keary’s, and Judge
Retchin’s opinions can be utilized by this Court as it conducts its own thoughtful
inquiry into the issues raised by the defendant. Moreover, this Court could choose
to adopt the record and findings created in those cases, and the government
would encourage it to do so.
Specifically, this Court should decline to consider the defendant’s complaints
about the reliability of the specific kits and instruments used to conduct the DNA
analysis, the alleged failure to conduct the tests properly, and the lack of blind
proficiency tests because, under Frye, those issues go to the weight of the
evidence, not its admissibility. The challenges to the PCR/STR process, and to the
process of calculating random match probabilities should be rejected because
those processes are scientifically accepted, as courts throughout the country have
repeatedly found.
The District of Columbia Court of Appeals (“DCCA”) has not addressed the
admissibility of DNA profile evidence since United States v. Porter, 618 A.2d. 629
(D.C. 1992) (“Porter II”).10/ When Porter II was decided, the use of DNA typing for
forensic purposes was still in its nascent stage. Ours was among the first jurisdictions
10/
In Porter II, the DCCA reviewed, and remanded, a decision
excluding the DNA evidence. See United States v. Porter, 1991 WL
319015 (D.C. Super. Ct. Sept. 20, 1991) (“Porter I”). On remand,
the DNA evidence was admitted. See United States v. Porter, 1994
WL 742297 (D.C. Super. Ct. Nov. 17, 1994) (“Porter III”).
14
to admit DNA evidence, which at the time was obtained
by the restriction
fragment length polymorphism (“RFLP”) method. The field of forensic DNA analysis
has evolved rapidly. In the 12 years since the Porter opinions, identification by DNA
typing has become commonplace; the methods used to perform DNA analyses
have become more powerful and more discriminating; the tools used to apply
those methods have been standardized; and forensic laboratories have adopted
quality assurance standards that reflect the maturation of the field of forensic DNA
analysis. The methods applied in this case – PCR amplification, STR typing, analysis
by laser fluorescent capillary electrophoresis, and calculation of the match
probabilities by the unmodified product rule – reflect that maturation.
Because there is no published appellate opinion in this jurisdiction affirming
the admissibility of the PCR/STR method and the methods for calculating match
probabilities used in these cases, those methods are theoretically proper subjects
for a Frye hearing. Nonetheless, this Court does not need to conduct an extensive
Frye inquiry. The PCR/STR methods used in this case have been scrutinized by the
scientific community and other courts for years, and there is virtually universal
agreement that they are generally accepted by the relevant scientific community
as reliable for forensic DNA analysis purposes. As a result, DNA evidence derived
from those methods is routinely admitted in state and federal criminal cases across
the country.
Similarly, the FBI's methods for calculating the random match
probabilities are generally accepted by scientists, and those statistics are routinely
15
admitted to explain the significance of a match between evidence and suspect
samples. Courts that adhere to the Frye standard have also consistently rejected
arguments, like the defendant’s, that laboratory proficiency testing procedures and
laboratory error rates, or the way in which scientific procedures were performed in
an individual case, are issues that affect the scientific acceptance of methods of
DNA analysis.
II.
Defendant’s Cold-Hit Motion
In Defendant’s Cold Hit Motion, defendant moves to exclude DNA evidence
under Frye on the grounds that the statistical calculation utilized by the government
to explain the significance of a DNA profile match that is initially derived from
trawling through a DNA database is currently the subject of a “raging debate with
scientists divided into three separate camps calling for three starkly different
approaches” (Cold Hit Motion at 1). The defendant submits that the Court should
exclude the DNA evidence until the alleged controversy is quelled. Id. at 2.
Defendant’s Cold Hit Motion is equally meritless. Defendant attempts to
concoct a scientific controversy over statistical methodologies when, in reality,
the various positions cited by the defendant merely reflect answers to different
questions that can arise when calculating the statistical probabilities relating to a
particular DNA profile in cases where the defendant is initially found by trawling
through a DNA database. As we show, defendant’s argument rests on three
false premises: 1) there is only one question that statistics can answer in a cold-
16
hit case; 2) the existence of more than one approach to addressing a question
means that none is generally accepted; and 3) a debate about the relative
merits of different statistical approaches is the equivalent of the “raging
controversy” over the fundamental reliability of those approaches.
Importantly, there is no controversy regarding the relevance of the
estimated rarity of the DNA profile at issue or the general acceptance and
admissibility of the Random Match Probability (“RMP “) to answer that question.
The RMP answers the question how rare is a DNA profile in a particular
population. The statistical method utilized to calculate RMP is generally
accepted and the rarity of a particular DNA profile never changes, regardless of
whether a defendant is first identified by searching a database. Thus, the rarity
of the DNA profile is always relevant for the trier of fact.
In 1992, the National Research Council (NRC I) formulated an approach
to statistical calculations in the context of a cold-hit case which understated the
rarity of the DNA profile to compensate for technological shortcomings in the
methodologies being used to amplify DNA in the early 1990s. Under the NRC I
approach, DNA markers used to perform the database search would be
discarded and the rarity of the DNA profile would be artificially understated by
limiting the RMP calculation to a completely new set of DNA markers. As
discussed below, this approach, is outdated and impractical, and deprives the
jury of relevant evidence. Hence, this approach should not be followed.
17
The RMP answers only one question that can arise in the context of a coldhit case, i.e. how rare is a DNA profile in a population (Question one). In 1996,
the National Research Council (NRC II) issued a second report in which the
committee addressed a second question that arises when a suspect is identified
through a search of a database, i.e., what are the chances of finding a
particular DNA profile in a database of a particular size (Question two). Since
this question is different from the one answered by the RMP, it results in a
different statistical calculation. NRC II assumes the relevance of Question Two
and advocates providing a Database Match Probability (DMP) to answer it. To
the extent there has been a scholarly discussion regarding statistical calculations
in a cold-hit case, the discussion has centered on the relevance of Question
Two. While NRC II assumed the relevance of Question Two, another group of
scholars opine that, although the second question might be of interest to
academicians, and the NRC II formula is an acceptable way to answer it, that
question is the wrong one to address in a criminal case. This group believes, in
effect, that no other probability figure needs to be introduced with, or instead
of, the RMP.
The government intends to introduce only the RMP numbers that represent
the estimated frequency with which the DNA profiles found in the evidence
samples would be expected to occur in four major population groups. We
show, the rarity of the DNA profile is always relevant and presentation of the RMP
18
alone does not risk suggesting potentially prejudicial information about the
defendant’s criminal record. Additionally, presentation of the RMP in a cold hit
case is consistent with the practice of almost every DNA forensic laboratory in
the country.
If the Court believes that the likelihood of finding a match to the evidence
profile in the offender database is relevant, the government does not object if
the defense wants to introduce, in addition to the RMP figures, the DMP figure as
calculated by the generally accepted formula recommended by the NRC II
committee in 1996. There is no controversy in the relevant scientific community
that the use of the NRC II formula is both a correct and conservative (as well as
a defendant-favoring) way to answer the second question.
III.
The law in the District of Columbia.
District of Columbia courts evaluate the admissibility of novel scientific
evidence by the standard first announced in Frye v. United States, 54 U.S. App.
D.C. 46, 47, 293 F. 1013 (1923): where expert testimony is not based on a "wellrecognized scientific principle or discovery, the thing from which the deduction
is made must be sufficiently established to have gained general acceptance in
the particular field in which it belongs." Id. at 1014. See Bahura v. S.E.W.
Investors, 754 A.2d 928, 943 n.15 (D.C. 2000) (affirming that Frye test remains in
effect in the District of Columbia).11/
11/
The defendant incorrectly suggests that this Court would be free
19
to apply the federal standard for admissibility announced in
Daubert v. Merrell Dow Pharmaceutical, Inc., 509 U.S. 579
(1993)(Defendant’s Supplemental Motion at 9 n.10). The Court of
Appeals has recently affirmed that the Frye test still applies in
the District of Columbia, see Bahura, 754 A.2d at 943, and this
Court is not free to disregard that binding precedent.
20
“Under Frye, the proponent of a new technology must demonstrate by a
preponderance of the evidence that this technology has been generally
accepted in the scientific community.” Porter II, 618 A.2d at 633. “‘The issue is
consensus versus controversy over a particular technique, not its validity.’” Id. at
634 (quoting Jones v. United States, 548 A.2d 35, 42 (D.C. 1988)). “[T]he focus is
primarily on counting scientists’ votes rather than on verifying the soundness of a
scientific conclusion.” Jones, 548 A.2d at 42. However, unanimity among
scientists is not required. Porter II, 618 A.2d at 634.
Contrary to the defendant’s contention (Defendant’s Supplemental
Motion at 10-11), the Frye test in this jurisdiction does not condition admissibility
on a pre-trial showing that generally accepted techniques have been
appropriately applied by the laboratory performing the DNA analysis. “[T]he
Frye test ‘begins – and ends – with . . . whether there is general acceptance of a
particular scientific methodology, not an acceptance, beyond that, of
particular study results based on that methodology.’” Porter II, 618 A.2d at 634
(quoting Porter I, [1991 WL 319015 at *15] (in turn quoting Ibn-Tamas v. United
States, 407 A.2d 626, 637-39 (D.C. 1979))). “Any failure by the scientists to adhere
to the appropriate procedure is, of course, a proper subject of inquiry, but does
not raise an issue which implicates Frye.” Id. at 636.12/ “Once the scientific
12/
Like the District of Columbia, many states apply the Frye
general-acceptance standard to the theory and technique of a novel
scientific method, but treat the question of whether a generally
21
method is shown to be generally accepted, it is presumptively reliable, although
the opponent may challenge the weight of the evidence.” United States v.
Bridgett, 120 Daily Wash. Law Rptr. 155, at 1702 (D.C. Super. Ct. Aug. 11,
1992)(citing Williams v. District of Columbia, 558 A.2d 344, 346 (D.C. 1989)).
This Court has broad discretion as to the kinds of evidence it may consider
in a Frye inquiry. The DCCA has held that “the appellate court, like the trial court,
may, and often should, pay attention not only to expert evidence of record but
also to judicial opinions in other jurisdictions that have considered the question,
accepted technique was properly performed as one of weight, not
admissibility. See, e.g., State v. Cauthron, 846 P.2d 502, 507
(Wash. 1993) (conditioning admissibility on absence of error is
“inappropriate in jurisdictions utilizing the Frye standard of
admissibility [because the] core concern of Frye is only whether
the evidence being offered is based on established scientific
methodology”).
Other states add requirements to Frye’s “general acceptance”
standard before admitting novel scientific evidence.
This
variation is known as “Frye-Plus.” See Taylor v. State, 889 P.2d
319, 325 n.13 (Okla. 1995) (comparing jurisdictions, like Oklahoma,
that adhere to a “pure” Frye test with those that apply a “FryePlus” test). See also, e.g., People v. Kelly, 549 P.2d 1240 (Cal.
App. 3d 1976) (adopting three-part admissibility standard: Part I
incorporates Frye general acceptance test; Part II looks at
qualifications of the expert witness; Part III requires proof that
the scientific test was performed according to a generally accepted
methodology); State v. Nose, 649 N.W.2d 815, 819 (Minn. 2002)
(state's Frye-Mack test "asks first whether experts in the field
widely share the view that the results of scientific testing are
scientifically reliable, and second whether the laboratory
conducting the tests in the individual case complied with
appropriate standards and controls"); People v. Castro, 545
N.Y.S.2d 985 (N.Y. Sup. Ct. 1989) (applying three-part test that
adds requirement that techniques be properly performed).
22
as well as to relevant legal and scientific commentaries in which the technique
or test has been scrutinized.” Jones, 548 A.2d at 41 (emphasis added)
(upholding trial court's admission of EMIT drug-test results based on judicial
notice of evidentiary record compiled in different case, and other court opinions
that relied on expert testimony and review of scientific literature).
In determining the admissibility of scientific evidence under Frye v. United
States, 54 U.S. App. D.C. 46, 293 F.1023 (1923), this Court may take judicial notice
of extra-record materials, including expert testimony from other proceedings.
See District of Columbia ex rel. J.A.B. v. W.R., Jr., 1991 WL 214204, *7-*8 (D.C.
Super. Ct. (1991) (“[E]xpert testimony in other cases, subject to crossexamination, can be probative of the general acceptance of a scientific
technique. . . . This Court can also take judicial notice of such expert testimony.”)
(citing Jones v. United States, 548 A.2d 35, 36 (D.C. 1988)); see also United States
v. Bridgett, 120 Daily Wash. Law Rptr. 155, at 1697 (D.C. Super. Ct. Aug. 11, 1992)
(taking judicial notice of expert testimony from proceedings in Porter I). The
testimony does not have to come from a court in this jurisdiction to be helpful to
the admissibility determination. See Porter I, 1991 WL 319015, *28 n.47
(acknowledging usefulness of expert testimony from admissibility hearing in Ohio
federal district court); accord Porter II, 618 A.2d at 631 n.4.
Where the scientific literature, and opinions and records from other cases
clearly demonstrate the general acceptance of a scientific method, a court
23
may even dispense with live testimony. See, e.g., Porter II, 618 A.2d at 635;
Bridgett, 120 Daily Wash. Law Rptr. 155, at 1697.13/ In fact, the Court of Appeals
rejected a challenge to the reliability of a scientific procedure used to test
sobriety (the Horizontal Gaze Nystagmus Test (“HGN”)) simply by taking judicial
notice that “‘the great weight of scientific literature supports [the] reliability [of
the HGN] and [that] the majority of jurisdictions around the country have
declared HGN testing to be reliable.’” Karamychev v. District of Columbia, 772
A.2d 806, 812 (D.C. 2001) (quoting Schultz v. State, 664 A.2d 60, 74 (Md. App.
1995)). Moreover, although the relevant scientific communities include those of
forensic DNA science, molecular biology, and population genetics, “the views
of forensic scientists have weight and must be considered.” Porter II, 618 A.2d at
634.
IV.
DNA analysis by the PCR/STR method is universally
accepted in the relevant scientific community and the
courts.
A.
Background of DNA analysis.
13/
Although this Court may take judicial notice of judicial
opinions and expert testimony from other hearings on the same
issue, we object to, and ask the Court to disregard, the
defendant’s citations to opinions and testimony that are not
readily available and have not been provided to counsel and the
Court for inclusion in the record in this case.
See People v.
Morganti, 50 Cal. Rptr. 2d 837, 852 n.19 (Ct. App. 1996) (court
declines to consider unpublished opinions that have not been made
part of record in admissibility proceedings).
24
The theories behind DNA typing are now relatively familiar. See, e.g.,
Porter II, 618 A.2d at 632; Bridgett, 120 Wash. L. Rptr. 155, at 1697, 1700.14/ The
nucleus of most cells in a human body contains 23 pairs of worm-like
microscopic bodies called chromosomes, each pair containing one
chromosome inherited from the mother and one from the father. At the core of
each chromosome is a long thin strand of the molecule deoxyribonucleic acid,
or DNA. In general, the DNA within an individual is identical, but, as with
fingerprints, no two individuals have the same DNA (with the exception of
identical twins).
The DNA molecule looks like a rope ladder twisted into a helix. The sides
of the ladder are phosphate-sugar strands. The rungs are pairs of “bases” or
nucleotides. There are four types of nucleotides: adenine (“A”), thymine (“T”),
guanine (“G”), and cytosine (“C”). A always pairs with T, and G always pairs
with C, so there are only four possible combinations of base pairs at a single rung
(AT, TA, GC, CG).
The entire human DNA makeup, or “genome,” contains approximately
three billion base pairs, ninety-nine percent of which are identical among
humans. Forensic DNA identification is based on the ability to recognize
14/
For additional information on the theory, methods, and history
of forensic DNA testing, see generally Butler, J., Forensic DNA
Typing: Biology & Technology Behind STR Markers (Academic Press
2001).
25
differences in selected sequences of base pairs at specific sites, or loci, in the
remaining one percent – approximately three million base pairs – which may
vary from person to person. A variation in a base-pair sequence at a particular
site, or locus, is called an “allele.” There could be several or even hundreds of
variations, or alleles, at a locus. Typically, the DNA sites chosen for forensic
examination contain highly variable, non-functional DNA sequences that are
repeated over and over again next to each other. These repeat regions are
called “variable number of tandem repeats” (“VNTRs”). One individual can be
distinguished from another by the number of tandem repeats found at these
VNTR sites.
B.
The PCR process.
As a general matter, polymerase chain reaction (“PCR”) is merely a
method of amplifying, or copying, a small DNA sample so that it can be easily
analyzed using other techniques. Thus, by itself, PCR “is not an analytic tool[.]
[R]ather [PCR] facilitates forensic (as well as other) applications by allowing a
scientist to take a sample of DNA [that] would generally be insufficient to detect
the characteristics of the DNA[] and amplify it until enough copies are available
for further analysis.” Office of Technology Assessment, Congress of the United
States, Genetic Witness: Forensic Uses of DNA Tests, at 48 (July
1990)(characterizing PCR as “molecular photocopying”). As explained in a 1996
report by the National Research Council (“NRC”):
26
The [PCR] process is similar to the mechanism by which DNA
duplicates itself normally. [It] consists of three steps. First, each
double-stranded segment [of DNA] is separated into two strands by
heating.15/ Second, these single-stranded segments are hybridized
with primers, short DNA segments (20-30 nucleotides in length) that
complement and define the target sequence to be amplified.16/
Third, in the presence of the enzyme DNA polymerase, and the four
nucleotide building blocks (A, C, G, and T), each primer serves as
the starting point for the replication of the target sequence. A copy
of the complement of each of the separated strands is made, so
that there are two double-stranded DNA segments. This three-step
cycle is repeated, usually 20-35 times. The two strands produce four
copies; the four, eight copies; and so on until the number of copies
of the original DNA is enormous. The main difference between this
procedure and the normal cellular process is that the PCR process is
limited to the amplification of a small DNA region.
Committee on DNA Technology in Forensic Science, National Research Council,
The Evaluation of Forensic DNA Evidence (1996) (“NRC II”), Appendix II, Tab A, at
69-70.
15/
The strands are separated lengthwise down the middle between
the two complementary nucleotides that form each base pair – a
process often described as “unzipping.”
16/
If the primer reads ACTT, then it will attach itself to a
segment that reads TGAA. A more detailed description of how the
PCR hybridization process works can be found in Butler, J. Forensic
DNA Typing, at 39-52; see also, e.g., State v. Lyons, 863 P.2d
1303, 1307-08 (Or. App. 1993), aff’d, 924 P.2d 802 (Or. 1996).
27
The defendant asserts that “[e]xcept in observing the high risk of
contamenation from multiple amplification cycles, he "does not take issue with
the PCR process as a method of amplifying nuclear DNA for analysis purposes"
(Defendant’s Supplemental Motion at 6 n.9).17/ The overwhelming weight of
scientific and legal opinion finds PCR to be generally accepted in the relevant
scientific community, and the results of PCR-based DNA typing are today
routinely admitted in courts throughout the country. As early as 1994, courts
deciding the admissibility of evidence derived from PCR-based DNA methods
found the PCR process to be “routine in many settings,” and “used by nearly
every molecular biologist in the world.” State v. Russell, 882 P.2d 747, 765 (Wash.
1994) (en banc) (describing various non-forensic applications of PCR-based DNA
17/
Other courts have reviewed alleged deficiencies in PCR-based
DNA typing systems, such as the risk of contamination, and
concluded that “the potential testing problems that [defendant]
cites are either detectable or preventable.” State v. Russell, 882
P.2d 747, 765, 767-68 (Wash. 1994) (en banc) (rejecting challenges
to PCR admissibility based on the alleged unreliability caused by
differential amplification, misincorporation, and contamination);
see also Commonwealth v. Sok, 683 N.E.2d 671, 679-81 (Mass. 1997)
(identifying 20 potential problems that “might inhere in any PCR
analysis,” but concluding, nonetheless, that “PCR-based testing . .
. is a scientifically valid means of comparing DNA profiles”),
abrogated on other grounds, In re Canavan, 733 N.E.2d 1042 (Mass.
2000); State v. Tankersley, 956 P.2d 486, 492 (Ariz. 1998) (en
banc)(the risk of contamination "has not rendered PCR-based
techniques unacceptable by the scientific community.
In fact,
erroneous amplification is far more likely to result in the false
exclusion, not inclusion, of a suspect. . . .
Moreover, the
possibility of contamination ‘may present an open field for crossexamination.'")
(internal
quotations
and
citation
marks
omitted)(emphasis added).
28
typing methods). The acceptance of PCR theory and technology in forensic
and non-forensic DNA analysis was well documented in the scientific literature.
See, e.g., State v. Lyons, 863 P.2d 1303 1310 (Or. App. 1993) (taking judicial
notice of a bibliography listing some 4,000 scientific articles and publications
relating to PCR-based DNA analysis). In addition, “PCR-based DNA analysis has
been used to clear persons suspected of a crime and to exonerate defendants
who have been wrongfully convicted.” Sok, 683 N.E.2d at 674 n.8.
The general acceptance of PCR-based techniques was affirmed by the
National Academy of Science's National Research Council (“NRC”), which
conducted two studies devoted exclusively to the use of DNA technology for
forensic purposes. In 1990, the NRC convened a special committee of
molecular biologists, population geneticists, and other scientists and experts,
which concluded after two years of study that “the theory of PCR analysis . . . is
scientifically accepted and has been accepted by a number of courts.” See
Committee on DNA Technology in Forensic Science, National Research Council,
DNA Technology in Forensic Science, at 70 (1992) (“NRC I”) (Appendix II, Tab
B).18/ Four years later, the NRC observed in a follow-up report that much more
18/
The conclusions of the NRC were central to the Court of
Appeals' decision in Porter to admit DNA evidence with some form of
random probability calculation. Porter II, 518 A.2d at 642 n.24,
643 n.26 (calling NRC report "authoritative" and "definitive").
The Court observed that the NRC’s conclusions regarding the
reliability of forensic DNA typing and appropriate methods for
calculating random match probabilities could “easily be equated
with general acceptance of those methodologies in the relevant
29
had been learned about PCR-based testing, and reaffirmed its acceptance as
a reliable technology for DNA profiling. See NRC II, Appendix II, Tab A, at 2, 23,
26. In light of the NRC’s endorsement of the PCR method, and the extent to
which PCR has been subject to scientific examination, it is not surprising that
“[t]he majority of courts . . . that have considered the issue have held that DNA
evidence derived from the PCR testing method satisfies the standards for
admissibility under either Frye or [Colorado Rule of Evidence 702's
relevance/reliability standard].” People v. Shreck, 22 P.3d 68, 79 n.15 (Colo.
2001)(collecting cases); People v. Butterfield, 27 P.3d 1133, 1143 (Utah 2001)
(same).
C.
The current generation of PCR-based analysis:
STRs.
1.
Background.
Because the PCR method alone merely copies DNA segments, a second
technique must be used to identify or “type” certain sites on the DNA strand for
use in comparison to a second DNA sample to determine if there is a match.
Since 1992, when Porter II affirmed the admissibility of the RFLP method, at least
four PCR-based typing methods have come into widespread use. The most
scientific community.” Id. at 643 n.26. See also Bridgett,
Daily Wash. Law Rptr. 155, at 1702 (bodies such as the
“serve[] as a voice of reason not only with respect to
divergent views postulated by the various experts who [testify]
. , but also with respect to the divergent views expressed in
numerous scientific articles submitted by the parties”).
30
120
NRC
the
. .
the
current method – which examines DNA segments called short tandem repeats
(“STRs”) – was used in the Jenkins case.19/
19/
The other three techniques, which are predecessors to the PCRSTR methods used here, involve 1) a single locus called DQ-Alpha
(also denoted “Dqα,” “DQ-α,” or “DQA1"); 2) five loci (low-density
lipoprotein receptor (LDLR), glycophorin A (GYPA), hemoglobin B
gamma globin (HBGG), D7S8, and group-specific component (GC)) that
are analyzed through the AmpliType® Polymarker PCR amplification
and typing kit (“PM”); and 3) another single locus named D1S80,
which is a 16-base-pair VNTR. See, e.g., Sok, 683 N.E.2d at 679-81
(describing various systems). Courts have routinely admitted DNA
match results from these three testing methods based on findings
that the methods are generally accepted in the scientific
community. Id.
31
The PCR/STR method represents, to date, the most powerful of the analytic
tools used for DNA typing. Just like the RFLP process accepted in Porter, STR
technology examines non-functional DNA sites, or loci, where there are basepair sequences that repeat themselves in varying numbers. Unlike the RFLP
process, which examines alleles that range from 500 to 10,000 base pairs in size,
the STR process focuses on tandem repeats in which the alleles are much
smaller, ranging from 100 to 400 base pairs.20/
Once DNA for analysis is obtained, the target STRs in that DNA are
identified and marked during the first cycle in the PCR amplification process. A
20/
Much of the theory and technology behind the RFLP method is
similar to the theory and technology behind the PCR/STR method,
although the STR method is much simpler. RFLP testing involves a
seven-step process: removal of the DNA from the evidence sample
("extraction"); use of an enzyme-based process to separate targeted
sequences of base pairs from the DNA molecule ("digestion"); use of
a gel-electrophoresis process to further separate the targeted
sequences by length ("separation by gel electrophoresis"); severing
of the targeted sequences lengthwise into complementary halves and
transfer to a different medium for further processing ("Southern
transfer"); application of radioactively charged single-stranded
complementary segments of DNA, called probes, to identify the
target DNA fragments ("hybridization"); placement of radioactivelymarked segments between x-ray film to create visual patterns of
bands, or autoradiographs, unique to each targeted DNA fragment
("autoradiography"); and comparison, first by a trained analyst,
then by a computer process, of the autoradiographs produced by the
evidence samples and the known samples (e.g., from a victim and a
suspect) to determine whether there is a match ("interpretation").
Porter I, 1991 WL 319015, at *3-*5. RFLP testing cannot identify
the exact number of VNTRs, so the length must be estimated, and
comparisons must be made using “match windows” which compensate for
known measurement error. Id. at *5. If fragments from a suspect’s
DNA sample fall within the same match window as fragments of DNA
from the evidence sample, then the samples will be called a match.
32
piece of DNA is heated until it splits into two strands, then short pieces of
synthetic DNA, called primer pairs, are added to the DNA. Each primer pair will
attach itself at either end, and outside of, an area of DNA known to contain a
specific STR. Chemicals are then added to induce replication, or copying of
only the desired STR sites. This process is repeated many times, until an enormous
number of copies of the targeted STRs are obtained from the original source of
DNA.
The simplest way to mark and copy an STR is to use a “monoplex” process,
in which only one primer pair is used during the PCR cycle and, thus, only one
targeted STR locus is amplified. More useful, however, is a “multiplex” process,
during which several primer pairs are used simultaneously and multiple targeted
STR loci are amplified concurrently. In a multiplex process, the various primers
for the targeted loci contain different colored fluorescent dyes, so that alleles at
different STR loci can be distinguished from one another later in the process.
The two commercial STR kits used in this case together identify 13 separate
STR loci on the DNA molecule. Profiler Plus enables the amplification and typing
of the following loci: D3S1358, D7S820, vWA, FGA, D8S1179, D21S11, D18S51,
D5S818, and D13S317. Cofiler enables amplification and typing of the loci
D16S539, THO1, TPOX, and CSF1PO, as well as two loci also targeted by Profiler
Plus, D3S1358 and D7S820.21/ By testing the same two loci, the two kits act as
21/
The labels usually identify the chromosome and the specific
33
internal accuracy controls for every analysis in which they are both used. Those
combined loci correspond to the 13 loci used in a national databank containing
DNA profiles of persons convicted of crimes, the Combined DNA Index System or
“CODIS,” which Congress authorized in 1994. See 42 U.S.C. § 14132 (West 2000).
The 13 loci were selected for CODIS through a collaborative process involving
FBI and 21 forensic laboratories based on underlying genetic research that had
validated these sites for the variability and genetic independence necessary to
allow them to be used for identification purposes. See United States v. Trala, 162
F. Supp. 2d 336, 343 (D. Del. 2001). The Profiler Plus and Cofiler kits were
developed to identify the CODIS loci.
After the target STR loci are amplified through PCR, the different STR
segments of DNA are separated by a process called capillary electrophoresis
(“CE”). Like the gel-electrophoresis process approved in Porter I, see 1991 WL
319015, *4, the CE process uses an electric current to draw the amplified DNA
through a sieve-like medium. A series of DNA fragments of known size, called
“standards,” are marked with a red dye and drawn through the medium along
with the unknown DNA fragments. The length of each STR can be used to
determine how many repeats are present in a fragment and thus to determine
an allele designation. The length of the STR can be calculated by how long it
site on the chromosome at which these particular STRs can be found.
34
takes it to move through the medium in comparison to the time it takes the size
standard to move through the gel. Shorter STRs move more quickly.
Instead of running the DNA fragments across a flat bed of gel, as in RFLP,
the CE process in the instant cases was conducted with a machine called the
310 Analyzer, which draws the DNA fragments through a narrow capillary tube
filled with a polymer. Also, instead of recording the position of the fragments
using radioactive probes to create autoradiographs, as in RFLP, the 310 Analyzer
sends a laser beam through a small window in the capillary, which illuminates
the fluorescent dyes attached to the target sequences and the red size
standard as they pass the window. The Analyzer distinguishes the various dye
colors by the differences in fluorescent wavelengths, and records how long it
takes each unknown fragment and the known size standard to travel through
the gel.
After the 310 Analyzer completes the fragment separation and collection
of data on the colors and relative speeds of the DNA fragments, that information
is analyzed by two computer programs, and the results are reported on a graph,
or electropherogram. Typically, an electropherogram will show three or four
rows of lines with a series of clusters of peaks of varying heights and colors on
them.22/ Each cluster represents an allele site, or locus. If sufficiently high, each
22/
Sample electropherograms depicting the results of the Profiler
Plus and Cofiler tests can be found at pp. 9-3 to 9-6 of the FBI
Laboratory’s “Short Tandem Repeat Analysis Protocol” (hereafter
35
peak within a cluster, or locus, will represent an allele. Each peak is labeled with
a number representing the number of repeats found at that allele. The analyst
interprets the electropherogram to determine, among other things, whether the
peaks shown represent true alleles, and whether they indicate one or more
contributors of DNA. In contrast to RFLPs, whose length could only be
approximated, STRs can be measured down to the number of repeated base
pairs constituting each allele. For each individual, the genotype at a locus will
be described by two numbers, one each for the number of repeats on each of
the paired chromosomes (maternal and paternal) within the allele (e.g., “16,
18").
Once the allele pairs are determined for each of the 13 separate loci
identified by the Profiler Plus/Cofiler/310 Analyzer system, the evidence sample
profiles are compared to the known sample profiles to see if there is, or is not, a
match. As is true with all of the DNA typing methods, if a profile match is found,
then the analyst goes on to calculate the random-match probabilities. See infra
at Section VII.
“FBI Protocols”) (Appendix II, Tab F).
36
2.
The STR method is generally
accepted.
Because STR-based typing is of more recent vintage than the PCR
method, the courts began to address the admissibility of results from STR testing
more recently. Nonetheless, since 1997, when the first appellate decision to
address STR typing appeared, the overwhelming majority of courts to address
this issue has found the STR process to be well accepted in the scientific
community.23/ Those courts rely in large part on the NRC’s endorsement of the
STR method in its 1996 report (“NRC II”). Judge Richter recognized this
acceptance in the Roberts and Veney cases concluding that “The government
has met its burden in establishing that STR-based typing is generally accepted.”
(Roberts/Veney Order at 13).
Although the authors of NRC II acknowledged that the use of STRs was
relatively new in 1996, they expressed no reservations about the scientific
acceptance of the underlying principles and techniques. In fact, the report
emphasized the scientific acceptance of all of the profiling techniques
considered, which included PCR-based STR analysis:
23/
Following an extensive admissibility hearing at which seven
expert witnesses testified, one Michigan trial judge concluded:
“The use of STRs is so accepted that journals will no longer accept
articles regarding their use; there is nothing left to explore in
the judgment of the world’s scientists.” People v. Phillips, Case
No. 00-02025-FC, Op. at 7 (Mich. Cir. Ct., Kent Co., Oct. 20, 2000)
(Appendix I, Tab L).
37
We affirm the statement of the 1992 report that the molecular
technology is thoroughly sound and that the results are highly
reproducible when appropriate quality-control methods are
followed. The uncertainties that we address in this report relate to
the effects of possible technical and human errors and the
statistical interpretation of population frequencies, not to defects in
the methodology itself.
NRC II at 23. Similarly, the National Institute of Standards and Technology “has
determined that there are several advantages of using STRs over conventional
techniques, and that the use of STRs for genetic mapping and identity testing
has become widespread among DNA typing laboratories.” Shreck, 22 P.3d at
80 (citing John M. Butler & Dennis J. Reeder, “Short Tandem Repeat DNA Internet
Database,” http://www.cstl.nist.gov/biotech/strbase/intro.htm).
Appellate courts in at least ten states have found DNA profile evidence
from PCR/STR multiplex testing to be admissible, and many have admitted the
results of testing conducted by the same kits used in this case - the Perkin Elmer
Profiler Plus and/or Cofiler kit, and the 310 Analyzer. See State v. Traylor, 656
N.W.2d 885 (Minn. 2003)(reversing decision to exclude DNA evidence; state
supreme court finds that PCR/STR testing using the Profile/Cofiler kits and the 310
Analyzer is generally accepted); Troxell v. State, 778 N.E.2d 811, 815-816 (Ind.
2002)(affirming trial court’s determination that PCR/STR testing by FBI laboratory
was “reliable and generally accepted in the relevant scientific community”);
People v. Hill, 107 Cal. Rptr. 2d 110, 117-18 (Ct. App. 2001) (affirming trial court's
38
refusal to conduct hearing on admissibility of results of Profiler Plus test kit,
because kits are just a means of implementing PCR/STR technique which has
already achieved general acceptance (citing People v. Allen, 85 Cal. Rptr. 2d
655, 659-60 (Ct. App. 1999) (STR testing found generally accepted under
California's Frye-Plus standard));24/ Shreck, 22 P.3d at 81 (adopting Colorado
Evidence Rule 702 relevance/reliability test in place of Frye; finding STR method
reliable; no need to examine particular Profiler kit); Yisrael v. State, 827 So. 2d
1113, 1114-1115, (Fla. Ct. App. 2002) (affirming admissibility under Frye of results
of Profiler Plus and 310 Genetic Analyzer); State v. Lemour, 802 So. 2d 402, 40508 (Fla. Ct. App. 2001) (admitting, under Frye standard, results of PCR/STR triplex
kit created by private lab), review denied, 821 So. 2d 297 (Fla. 2002);
Commonwealth v. Rosier, 685 N.E.2d 739, 743 (Mass. 1997) (PCR-based tests,
including STR, are scientifically valid); Watts v. State, 733 So. 2d 214, 222-23, 227
(Miss. 1999) (affirming, under a Frye-Plus test, trial court’s admission of PCR-based
typing, which included analysis by an STR triplex system); State v. Salmon, 89
S.W.3d 540, 542-545 (Mo. Ct. App. Oct. 8, 2002) (upholding, under Frye, results of
PCR/STR-based tests, based on testimony of one expert and judicial notice of
24/
The PCR/STR test kit at issue in Hill was the Profiler Plus
kit used in the instant case.
The court found no legal
significance in the fact that the Allen opinion, on which the Hill
court relied for the general acceptance of STR testing, decided the
admissibility of a different kit that tested fewer loci (a kit by
Promega that tested only four loci). Hill, 107 Cal. Rptr. 2d at
117-18.
39
appellate decisions from other states admitting results from similar PCR/STR tests);
State v. Jackson, 582 N.W.2d 317, 325 (Neb. 1998) (upholding admission of results
of PCR/STR testing under Frye-Plus standard); Butterfield, 27 P.3d at 1141-45
(reliability test under state rules of evidence; taking judicial notice of general
acceptance of PCR/STR analysis, including acceptance of the Profiler Plus and
310 Genetic Analyzer, as expressed in scientific publications and opinions from
other jurisdictions).
In addition to those recent appellate decisions, the trial courts that have
examined PCR/STR-based DNA analyses have overwhelmingly found those
methods to be generally accepted in the scientific community. As indicated
below, most of those courts applied the Frye general-acceptance standard, or
a Frye-Plus standard, and many admitted the results of the Perkin Elmer Profiler
Plus and/or Cofiler kits, and the 310 Analyzer. Copies of unpublished opinions
listed below are provided in Appendix I, at the tab indicated.25/
State v. Lynch, CR 98-11390, Ruling at 6 (Ariz. Super. Ct., Maricopa
Co., Aug. 20, 1999)(Frye jurisdiction [see Tankersley, 956 P.2d at 491];
“DNA analysis using STR testing [Profiler Plus and Cofiler] is generally
(actually universally) accepted in the forensic science community”)
(Tab A);
People v. Hunt, Case No. SA034500, Transcript of Oral Ruling (Cal.
Super. Ct., Los Angeles Co., Oct. 24, 2000) (Frye-Plus; admitting
evidence from Profiler Plus and Cofiler)(Tab B);
25/
The unpublished opinions appear in Appendix I as they are
listed in the text: in alphabetical order by state, and, within
each state, in reverse chronological order.
40
People v. Elizarraras, Case No. 50651, Ruling (Cal. Super. Ct., Tulare
Co., Oct. 13, 2000)(Frye-Plus; general acceptance hearing not
required for kits but ruling in the alternative that results from Profiler
Plus and 310 Analyzer admissible) (Tab C);
People v. Moevao, Case No. 168277, Opinion and Order (Cal.
Super. Ct., San Francisco Co., July 25, 2000)(Frye-Plus; admitting
results derived from Perkin Elmer Blue and Green I kits, which were
later incorporated in Profiler Plus and Cofiler kits, laser fluorescent
capillary electrophoresis, and 310 Analyzer; proceedings involved
25-day hearing with 8 witnesses and 60 exhibits, and resulted in over
2300 pages of transcripts) (Tab D);
People v. Hill, Case No. 232982, Ruling (Cal. Super. Ct., Santa
Barbara Co., April 18, 2000)(Frye-Plus; finding admissible PCR-based
STR tests using unnamed kits developed by Perkin Elmer) (Tab E);
aff'd, 107 Cal. Rptr. 2d 110 (Ct. App. 2001);
People v. Bertsch, et al., Case No. 94FO7295, Transcript of Oral
Ruling (Cal. Super. Ct., Sacramento Co., Oct. 20, 1999)(Frye-Plus;
holding that California law does not require kits or instruments used
to implement PCR/STR technique to meet general-acceptance
standard, but, if it did, Profiler Plus and 310 Analyzer meet that
standard) (Tab F);
State v. Flores, No. 99CR2960, Transcript of Oral Ruling (Colo. Dist.
Ct., City and Co. of Denver, Dec. 28, 2000), (Frye test; admitting
results of Profiler Plus and 310 Analyzer) (Tab G);
State v. Flores, No. 99CR2022, Transcript of Oral Ruling (Colo. Dist.
Ct., Adams Co., Oct. 20, 2000)(Frye test; admitting results of Profiler
Plus) (Tab H);26/
State v. Grant, 32 Conn. L. Rptr. 30, 2002 WL 853627 (Conn. Super. Ct.
April 9, 2002) (Daubert standard; court finds Profiler Plus/Cofiler
results admissible based on judicial notice of decisions from other
26/
There are two decisions, by two different Colorado trial
courts, involving the defendant Reynaldo Luna Flores.
41
jurisdictions and, in the alternative, after application of Daubert
factors to evidence);
State v. Yisrael, No. 99-20176CF10A, Ruling at 3-4 (Fla. Cir. Ct.,
Broward Co., Aug. 8, 2000)(“DNA typing using the Profiler Plus Kit
with the 310 Genetic Analyzer has now gained general
acceptance by the relevant scientific community and thus meets
the Frye standard”) (Tab I), aff'd, 2002 WL 31355273 (Fla. Ct. App.
2002);
Commonwealth v. Gaynor, Case No. 98-0965-0966, Memorandum
of Decision (Mass. Super. Ct., Hampden Co., Apr. 13, 2000)(may use
Frye general acceptance or modified Daubert test;27/ admitting
results of Profiler Plus, Cofiler, and 310 Analyzer) (Tab J);
People v. Kopp, et al., Case No. 00-04014-FH, et al., Opinion at 11
(Mich. Cir. Ct., Kent Co., Oct. 20, 2000)(Frye-Plus jurisdiction; expert
witnesses “establish by what can only be called overwhelming
evidence that the PCR STR methodology as well as the Perkin-Elmer
CoFiler and ProFiler kits utilizing the 310 Genetic Analyzer . . . have
received broad and, in fact, universal acceptance in the scientific
community”) (Tab K), aff'd 2002 WL 31058350 (Mich. Ct. App. 2002)
(assuming, arguendo, there was error, error was harmless given
weight of evidence);
People v. Phillips, Case No. 00-02025-FC, Opinion (Mich. Cir. Ct., Kent
Co., Oct. 20, 2000) (Frye-Plus; finding that prosecution and defense
witnesses agree that PCR-based STR analysis is generally accepted,
and rejecting defense expert’s opinion that results from 310 Genetic
Analyzer are not) (Tab L);
People v. Cavin, Case No. 00-4395-FY, Opinion and Order (Mich.
Cir. Ct., Lake Co., Oct. 18, 2000) (Frye-Plus; after considering
27/
Massachusetts courts are allowed to evaluate the admissibility
of novel scientific evidence under either the Frye generalacceptance standard or a modified relevance/reliability standard as
expressed in Daubert, 509 U.S. 579. See Commonwealth v. Lanigan,
641 N.E.2d 1342 (Mass. 1994) (noting that in most cases general
acceptance will be the significant and “often the only issue”).
42
testimony of seven expert witnesses, court finds results of Profiler Plus
and 310 Analyzer admissible)(Tab M);28/
State v. Roman Nose, 649 N.W.2d 815 (Minn. 2002)(trial court originally
admitted the DNA evidence without conducting an evidentiary hearing.
The state supreme court later held that, under Minnesota law, such a
hearing was required. On remand, after receiving numerous articles and
other exhibits, and hearing the testimony of thirteen witnesses, some of
which addressed topics beyond the issues relevant to general
acceptance, the trial court in Roman Nose concluded that “it is generally
accepted in the relevant scientific community [including scientists
experienced in molecular genetics, population genetics, and forensic
science] that” 1) PCR/STR amplification and typing methods, 2) PCR/STRbased capillary electrophoresis analysis of DNA, and 3) application of the
PCR/STR method of analysis by the Profiler Plus and Cofiler kits, the 310
Genetic Analyzer, and the Genescan and Genotyper software “produce
results that are scientifically reliable as accurate, and that the combined
methods of PCR/STR analysis and statistical formulas used in the field of
population genetics accurately determine certain frequencies necessary
to understand the significance of the results of DNA profile matches or
non-matches” (see Order dated January 3, 2003, Appendix VI Tab B at 2729). The trial court also concluded that using a random match probability
calculation for a single-source DNA sample, or, in some circumstances, for
a mixed DNA sample (i.e., a sample containing DNA from more than one
contributor) where the profile of an individual contributor can be
discerned, is generally accepted. (Appendix VI at Tab B)
28/
The Kopp, Phillips, and Cavin cases from Michigan were decided
by different judges based on the same evidentiary hearing at which
six experts testified that the PCR and STR methods, and the Perkin
Elmer kits and 310 Analyzer, all were generally accepted by the
scientific community.
See Kopp, Op. at 2 (Appendix I, Tab K).
Under Michigan law, the judges who presided jointly over this
consolidated record were required to find that the experts were
disinterested witnesses before they could give their testimony any
weight. See Kopp, Op. at 3-4, 11 (Appendix I, Tab K); Phillips,
Op. at 2-3, 7-8 (Appendix I, Tab L); Cavin, Op. at 17-18 (Appendix
I, Tab M). The Cavin opinion, at 18-43, summarizes the testimony.
43
State v. Kirkendahl, Case No. 00044987, Order (Minn. Dist. Ct., 4th
Dist., Hennepin Co., Jan. 16, 2001) (Frye-Plus jurisdiction; although
theory and techniques of PCR/STR analysis are all that must pass
general acceptance test, “tools” applying those techniques –
Profiler, Cofiler, and 310 Analyzer – also pass State’s additional
reliability standard) (Tab N);29/
State v. Dishmon, File No. 9947345, Order and Memorandum at 8-9
(Minn. Dist. Ct., 4th Dist., Hennepin Co., Mar. 3, 2000) (Frye-Plus; Frye
does not require that kits and instruments be generally accepted in
scientific community, but if it did, Profiler Plus, Cofiler, and 310
Analyzer would meet that standard; findings based on testimony
from 11 experts) (Tab O);
State v. Keightley, Case No. 30R090100013, Docket Entry (Mo. Cir.
Ct., Webster C., May 22, 2002) (Frye jurisdiction; finding hearing not
necessary, and admitting results of Profiler Plus/Cofiler test kits based
on review of cases and scientific articles) (Tab P);
State v. Staples, Case No. CR1999-03841, Order (Mo. Cir. Ct.,
Jackson Co., Nov. 15, 2000)(Frye jurisdiction; admitting PCR-based
STR analysis conducted by FBI using an unnamed Perkin Elmer
system) (Tab Q);
State v. Whittey, Case No. 00-S-273-275, 942, Order (N.H. Super. Ct.,
Merrimack Co., May 22, 2001) (under Frye-Plus test, admitting results
from Profiler Plus/Cofiler/310 Genetic Analyzer kits and system) (Tab
R);
State v. DeLoatch, 804 A.2d 604 (N.J. Super. Ct. 2002) (upholding,
under Frye, admission of results of Profiler Plus/Cofiler/310 Genetic
Analyzer based on testimony of one expert and judicial notice of
opinions from other jurisdictions);
29/
The Kirkendahl court did not hear live testimony, but relied
instead on the transcripts of the testimony from 11 expert
witnesses in the Dishmon case, infra. The Minnesota Supreme Court
has recently disapproved of the practice of relying exclusively on
judicial notice of extra-record material in determining the general
acceptance of novel scientific techniques under that state's twopart Frye-Plus admissibility standard.
See State v. Nose, 649
N.W.2d 815 (Minn. 2002).
44
People v. Owens, 725 N.Y.S.2d 178 (Super. Ct., Monroe Co., 2001)
(denying, without a Frye hearing, motion to exclude DNA evidence
because admissibility of PCR/STR test results well established; here
tests performed by Profiler Plus and Cofiler kits).
Scientific and legal opinion weighs so heavily in favor of the admissibility of
the PCR/STR method of DNA typing that this court may, with confidence, hold
that the PCR/STR method is admissible under Frye by taking judicial notice of
those authorities. See Karamychev, 772 A.2d at 812; Porter II, 618 A.2d at 635.
V.
The defendant’s arguments against the DNA typing
methods in this case go to weight of the evidence, not
its admissibility.
Despite the weight of authorities that find the PCR and STR methods
admissible under Frye, the defendant contends that this Court cannot admit
evidence derived from those methods unless it also finds that the kits and
instruments by which those methods are applied, and the actual application of
those techniques by the individual FBI analyst in the Jenkins case, is also
generally accepted in the scientific community. The defendant asserts that the
DNA evidence in this case is inadmissible because Perkin Elmer does not disclose
the primer sequences used in its Profiler Plus and Cofiler kits; the FBI lab does not
conduct blind proficiency tests of its examiners and does not "track and disclose
(or estimate) error rates"; and the methodology used by the individual analyst in
his analyses of the DNA samples was unreliable. The defendant is wrong as a
matter of law and fact.
45
A.
The Court does not have to find that the
tools used to apply the PCR/STR technique
are generally accepted; even if it did, the
kits and instrument used in these cases are
generally accepted.
The defendant’s argument – that the DNA test results cannot be found
generally accepted under Frye because the Perkin Elmer company has not
publicized the primer sequences used in Profiler Plus and Cofiler – has been
rejected by courts across the country.
1.
No inquiry is required under
Frye.
This Court should decline to consider the defendant’s argument primarily
because, under Frye, the reliability of the tools used to apply generally
accepted scientific methods goes to the weight of the evidence, not its
admissibility. For example, appellate courts in California and Colorado reversed
trial courts that had excluded DNA evidence on the grounds that the kits had
not been generally accepted. See People v. Bokin, Case No. 168461, Order
(Super. Ct., San Francisco, May 6, 1999) (Frye-Plus standard); People v. Shreck,
Case No. 98CR2475, Ruling and Order (Dist. Ct., Boulder Co., Apr. 12, 2000) (Frye
standard), overruled, People v. Shreck, 22 P.3d 68 (Colo. 2001). The appellate
courts reversed the Bokin and Shreck trial courts in large part because the trial
courts extended the Frye test beyond its scope when they began to scrutinize
the tools used to apply otherwise accepted scientific techniques. The Colorado
Supreme Court overturned the trial court’s ruling in Shreck, saying, in part, that
46
the trial court erred by subjecting the Profiler Plus and Cofiler kits to an
admissibility analysis because “questions as to the reliability of the particular type
of multiplex kit go to the weight of the evidence, rather than its admissibility.”
Shreck, 22 P.3d at 81 (citing State v. Russell, 882 P.2d 747, 768 (Wash. 1994) (en
banc)).30/ Similarly, a California appellate court has effectively rejected the trial
court opinion in Bokin by affirming another trial court’s decision to admit the
results of the Profiler Plus kit without conducting any hearing on admissibility. See
People v. Hill, 107 Cal. Rptr. 2d 110 (Ct. App. 2001) (affirming Hill, No. 232982,
Appendix I, Tab E). The court of appeals held that California law did not require
the trial court to find that the Perkin Elmer kit used to perform the DNA analysis
was generally accepted because
The Profiler Plus kit does not embrace new scientific techniques. To
the contrary, it uses the PCR and STR testing methods which are
generally accepted by the scientific community. It is just more
sophisticated because it examines a greater number of genetic
markers.
Id. at 118.
30/
In reversing the trial court’s decision in Shreck, the
Colorado Supreme Court took the occasion to change from a Frye
admissibility standard to one based on Colorado Rule of Evidence
702 which, like its federal counterpart, looks at relevance and
reliability. Shreck, 22 P.3d at 78. However, as illustrated by
the Russell opinion, the Colorado Supreme Court’s reasoning
concerning the scope of a general-acceptance inquiry applies with
equal force to a Frye inquiry.
47
Other courts agree that, where methods such as PCR and STR are found
to be generally accepted in the scientific community, there is no need to
establish the general acceptance of the tools used to implement those
methods. See, e.g., Elizarraras, Ruling at 3-4 (Appendix I, Tab C) (where same
basic scientific principles are at work, and principles have been accepted by
scientists and the courts, kits not subject to general-acceptance test); Lemour,
802 So.2d at 407 (Frye test does not require court to find admissible the noncommercial PCR/STR triplex kit developed by private lab); Kirkendahl, Op. at 15
(Appendix I, Tab N) (“Frye evaluated a lie detector technique, not a specific
blood pressure cuff. The principles underlying fingerprint comparison are
generally accepted, so a crime lab should not have to show general
acceptance of its choice of every new fingerprint powder.”); Russell, 882 P.2d at
768 (Frye test does not require the general acceptance of the means by which
a DNA testing method is implemented because “[t]he . . . kit is simply one tool
for carrying out generally accepted [PCR-based DNA typing] methodology,
and any concerns about its implementation in a given case are matters to be
addressed to the trial court.”); cf. United States v. Trala, 162 F.Supp. 2d 336, 346
(D. Del. 2001) (applying Daubert standards, district court finds that "kits do not
represent separate part of the typing process, but rather, simply contain
materials for beginning of the [already accepted] PCR process").31/
31/
But cf. Bertsch, Tr. at 20363-65, 20373-74 (Appendix I, Tab F)
48
(kits and 310 Analyzer not subject to general-acceptance test;
however, court suggests that “information regarding an individual
kit may be relevant to initial general acceptance evaluation of a
test such as STRs,” id. at 20365).
49
This Court should decline to review the general acceptance of the Perkin
Elmer kits for the same reasons. Frye speaks in broad terms of novel scientific
theories and methods. In the Porter cases, neither the trial court nor the Court of
Appeals suggested that it was necessary to scrutinize the tools employed to
implement the RFLP method of analysis. Each court readily affirmed the rule in
this jurisdiction that the Frye inquiry “begins – and ends – with . . . whether there is
general acceptance of a particular scientific methodology,” not an
acceptance of anything beyond that. Porter I, 1991 WL 319015, *22; accord
Porter II, 618 A.2d at 633. It would be inconsistent with this reasoning to subject
the kits used in this case to a Frye inquiry. Rather, as other courts have done, the
Court should permit the defendant to scrutinize the application of otherwise
admissible scientific methods through the ordinary methods of cross-examination
and defense evidence at trial.
2.
The kits are generally
accepted.
Even if the general acceptance of the kits were a proper subject for a
Frye inquiry, this Court could find the kits admissible based solely on the findings
and opinions of the many courts that have held, within the past five years,
extensive evidentiary hearings and concluded that the results derived from the
Profiler Plus and Cofiler kits and 310 Analyzer are admissible. See, e.g., Traylor,
656 N.W.2d at 893, at 900 (court finds results from Profiler/Cofiler310 Analyzer
system both “generally accepted” and “reliable” under state’s Frye-plus
50
admissibility standard); Flores, 12/28/99 Tr. at 161-65 (Appendix I, Tab G)(based
on expert testimony and scientific literature, court finds DNA typing using Profiler
Plus and 310 Analyzer to be generally accepted); Yisrael, Ruling at 3-4
(Appendix I, Tab I)(“DNA typing using the Profiler Plus Kit with the 310 Genetic
Analyzer has now gained general acceptance by the relevant scientific
community and thus meets the Frye standard”); Kopp, Op. at 11 (Appendix I,
Tab K)(testimony of six expert witnesses “establish by what can only be called
overwhelming evidence that the PCR STR methodology as well as the PerkinElmer CoFiler and ProFiler kits utilizing the 310 Genetic Analyzer . . . have
received broad and, in fact, universal acceptance in the scientific
community”); Owens, 725 N.Y.S.2d at 841 (admitting DNA evidence without a
Frye hearing, based in part on finding that "[c]ourts throughout the country have
found that the Short Tandem Repeat (STR) DNA profiling, using the AmpF/STR
Profiler Plus and Cofiler PCR kits are reliable and generally accepted by the
scientific community") (collecting cases); Butterfield, 27 P.3d at 1144 ("the
forensic community and those quarters of the scientific community that have
used the [Profiler Plus and 310 Analyzer] uniformly assert the system's
reliability")(collecting scientific studies).32/
32/
The defendant’s cursory challenge to the 310 Analyzer and its
related Genescan and Genotyper software is wholly baseless. The
National Institute of Standards and Technology (“NIST”) considers
the method of laser fluorescent capillary electrophoresis ("CE") to
be an “established technology.”
See NIST, “STR Typing Technology
51
Judge Richter, recognizing this case law, further found the tools used by
the FBI to implement the PCR/STR technology were generally accepted, and
that the FBI laboratory’s protocols for implementing this technology were
minimally reliable and generally accepted. (Roberts/Veney Order at 13).
a.
Adherence to the TWGDAM
guidelines is not required for general
acceptance.
Review” (Appendix II, Tab H). So do courts throughout the nation.
See, e.g., Moevao, Op. at 30-38 (Appendix I, Tab D) (analysis by
CE method, particularly as applied by 310 Genetic Analyzer,
generally accepted, as shown by expert testimony and 21 scientific
articles); Yisrael, Ruling at 4 (Appendix I, Tab I)(finding 310
Analyzer has been subject to peer review because over 30 articles
have been published dealing with it or comparable instrument using
CE).
52
There is no merit to the defendant’s assertion that the kits cannot be found
to be generally accepted because Perkin Elmer did not comply with the
validation guidelines promulgated by the Technical Working Group on DNA
Analysis Methods (“TWGDAM”).33/ (Defendant’s Supplemental Motion at 21-22).
Our courts have never suggested that the scientific acceptance of a particular
DNA typing method depends on adherence to the TWGDAM guidelines, and
the vast majority of courts to have addressed this question concludes that the
TWGDAM guidelines were not intended to be used to restrict the admissibility of
DNA evidence. See, e.g., State v. Tankersley, 956 P.2d 486, 493 (Ariz. 1998)
(TWGDAM guidelines are not mandatory); Hill, 107 Cal. Rptr. 2d at 118 (rejecting
as "without merit" the argument that "TWGDAM guidelines on developmental
validation of DNA test kits are mandatory and the sine qua non for admissibility");
Elizarraras, Op. at 6 (Appendix I, Tab C)(“[TWGDAM] guidelines are [not]
mandatory; rather, as stated in the Introduction to the 1991 [TWGDAM]
Guidelines, failure to comply with each and every guideline, or use of
33/
TWGDAM was created by scientists at the FBI research
laboratory in the late 1980s to address the need for quality
assurance and quality-control standards for forensic laboratories,
which were increasingly using DNA analyses. Porter III, 1994 WL
742297, at *7.
TWGDAM recommended procedures for forensic DNA
laboratories to follow in such areas as validating new DNA
technologies, monitoring analysts’ proficiency, and documenting
test results. The first guidelines took effect in 1991. TWGDAM
updated them in 1995, primarily to address PCR-based systems. The
TWGDAM guidelines were later superseded by guidelines developed by
the DNA Advisory Board ("DAB") created by Congress in 1994. See
infra at note 33.
53
alternative or equivalent methods does not necessitate a finding of unreliable
results”);34/ Moevao, Op. at 26 (Appendix I, Tab D) (“failure to adhere literally to
the TWGDAM guidelines does not warrant exclusion of otherwise relevant
evidence”); Bertsch, Tr. at 20369 (Appendix I, Tab F)(TWGDAM guidelines “are
not conditions precedent that have to be met in order for a court to find
general acceptance”); Lemour, 802 So. 2d at 407 (TWGDAM guidelines are
merely advisory and, in any event, have been replaced by DAB guidelines);
Kopp, Op. at 13 (Appendix I, Tab K)(Frye-Plus law does not require that
validation studies meet standards set by a federal committee); Owens, 725
N.Y.S.2d at 183 (adherence to proper protocols and quality-assurance standards
goes to weight not admissibility); see also Bridgett, 120 Daily Wash. Law Rptr. 155,
at 1703 (noting that NRC called TWGDAM guidelines an “instructive example” of
quality-assurance and quality-control guidelines); cf. State v. Jobe, 486 N.W.2d
407, 419 (Minn. 1992) (chairman of TWGDAM testified that “the guidelines were
designed to be guidelines and not an inflexible set of rules”).
34/
The guidelines say
These are only guidelines and should be used as a model
for laboratory managers to set up an appropriate QA
program for their laboratory. This document should not
be construed as a mandate; it does not mean that failure
to comply with each and every guideline, or that the use
of an alternative or equivalent method is insufficient or
likely to produce incorrect or unreliable results.
Technical Working Group on DNA Analysis Methods, Guidelines for a
Quality Assurance Program for DNA Analysis (April 1991) (“TWGDAM
54
Guidelines”) (Appendix II, Tab G).
55
Moreover, the 1995 TWGDAM guidelines have been replaced by the
quality-assurance standards developed by the DNA Advisory Board (“DAB”),
which became effective in October 1998. See DAB Quality Assurance
Standards for Forensic DNA Testing Laboratories (1998) (“DAB Standards”)
(Appendix II, Tab C).35/ See, e.g., Traylor, 656 N.W.2d at 899 (TWGDAM guidelines
superseded by DAB standards); Cavin, Op. at 14 (Appendix I, Tab M)(same);
Kirkendahl, Op. at 17-18 (Appendix I, Tab N)(same; also noting that even
defense expert recognized the DAB as “an appropriate group to speak for the
scientific community on appropriate guidelines”); see also Porter III, 1994 WL
742297, at *7 (recognizing that Congress authorized DAB to set policy for quality
assurance in forensic DNA testing, and that TWGDAM guidelines would serve as
interim standards until DAB standards were issued). Although the defendant
argues that the TWGDAM guidelines should be followed because they have the
35/
Recognizing the importance of forensic DNA analysis, Congress
enacted the DNA Identification Act of 1994, which authorized
creation of a national convicted-offender DNA database, and
established a DNA Advisory Board (“DAB”), composed of scientific,
legal, and ethics authorities, to develop and recommend to the FBI
quality assurance standards for forensic DNA laboratories.
See
Porter III, 1994 WL 742297, at *7. Members were appointed by the
director of the FBI from a list of experts nominated by the
National Academy of Sciences and professional criminal forensic
societies. NRC II at 24. Using the 1995 TWGDAM guidelines as a
model, the DAB developed new laboratory standards that were issued
in final form in October 1998. The DAB expired in December 2000,
and its oversight responsibilities reverted to TWGDAM, which is now
called the Scientific Working Group on DNA Analysis Methods
(“SWGDAM”). No changes have been made in the quality-assurance
standards since the DAB expired.
56
imprimatur of the NRC, the NRC did not suggest that those were the only
adequate quality-assurance guidelines. In fact, in its 1996 report, the NRC
recommended that laboratories aspire to high quality standards “such as those
defined by TWGDAM and the DNA Advisory Board.” NRC II at 88.
“The DAB recommendations, which supersede TWGDAM guidelines, do
not require that scientists developing new DNA technologies publish
developmental validation studies in peer reviewed scientific journals.” Hill, 107
Cal. Rptr. 2d at 119; see DAB Standards, Appendix II, Tab C, at § 8. The DAB
Standards do require that novel methodologies undergo “developmental
validation to ensure accuracy, precision and reproducibility,” that such
validation be documented, and that laboratories conduct internal validation
studies before using new products. See DAB Standards, §§ 8.1.2, 8.1.3.36/ The kits
and instruments used in this case met all of those standards.
b.
The Profiler Plus/Cofiler/310
Analyzer system has been
proven reliable by laboratory
validation studies, published
peer-reviewed research, and
actual experience.
36/
“Developmental validation” refers to the basic research,
typically undertaken by a manufacturer, to ensure the reliability
and accuracy of its testing products before selling them to
laboratories. Laboratories perform “internal validation” studies,
which the DAB standards define as “an accumulation of test data
within the laboratory to demonstrate that established methods and
procedures perform as expected in the laboratory.” DAB Standards
(Appendix II, Tab C), Definitions, § 2(ff)(2).
57
In any event, whether or not the Perkin Elmer company publishes its
developmental validation studies, the Profiler Plus/Cofiler/310 Analyzer system
has been proven reliable in numerous other ways.
The vast majority of courts agrees that DNA typing methodologies can be
validated in a variety of ways, and that internal validation by the laboratories
that actually use the methodologies is particularly persuasive. This makes sense.
As one trial court that examined the Profiler, Cofiler, and 310 Analyzer system
concluded, after considering the testimony of 11 expert witnesses:
The system has been shown to work, time after time, by lab after
lab, with or without studies from [Perkin Elmer]. The system is like a
Model A Ford. Thousands of owners can tell us it works even if Henry
Ford can’t or won’t explain it. The customers have thoroughly and
scientifically validated this system.
Dishmon, Order at 15 (Appendix I, Tab O). See also, e.g., Gaynor, Op. at 3
(Appendix I, Tab J)(quoting Dishmon with approval); State v. Traylor, 656 N.W.2d
at 900 (reversing lower court, Minnasota Supreme Court held that PCR-STR
testing methodology was generally accepted in the relevant scientific
community; the standards of the DNA Advisory Board (“DAB”) were the
appropriate standards in determining foundational reliability, as required by
Minnesota law; the state laboratory complied with DAB standards; and
admission of the DNA test results, without public disclosure of primer sequences
or the manufacturer’s developmental validation studies, did not violate Traylor’s
right to due process); Lynch, Ruling at 5 (Appendix I, Tab A) (relying on testimony
58
from court-appointed neutral expert witness, court concludes that, “Rather than
focus on primer sequences[,] it seems that the focus should be on whether the
results obtained from kits are reproducible. . . . Primer sequences are not
necessary to see if the kits are working appropriately because labs can validate
the results on their own.”); Elizarraras, Ruling at 5-6 (Appendix I, Tab C) (“lack of
identification of the actual primer sequences is not fatal in being able to
determine whether the [Profiler Plus] kit is working properly because the various
laboratories can validate the results on their own.”); Bertsch, Tr. at 20377
(Appendix I, Tab F) (defense expert testified that he has no difficulty using Profiler
Plus kit without access to the manufacturer’s validation information, including
primers).37/ A Michigan court summarized the current legal consensus, saying
that, “although developmental data has been released slowly and in an almost
random manner, the extensive use of the system and recognized merits of . . .
Perkin Elmer . . . testing kits show mutual national and even international
37/
Interestingly, it has been reported that a NIST scientist has
determined the composition of the Perkin Elmer primers on his own,
apparently through “reverse engineering.” See J. Butler and P.
Vallone, “Determination of Commercial STR Kit Primer Sequences,”
(abstract attached at Appendix II, Tab I, p. 105). See also Cavin,
Op. at 39 (Appendix I, Tab M) (expert witness, an associate
director of a paternity-testing laboratory, testifies that, “with
access to proper lab,” he could determine Perkin Elmer primer
sequences “in a relatively short time”).
59
acceptance in the scientific community.” Cavin, Op. at 47 (Appendix I, Tab
M).38/
38/
The one study cited by the defendant (Defendant’s
Supplemental Motion at 20-21) does not support the argument that
the primer sequences are flawed.
See Shewale, J.G., et al.,
“Anomalous Amplification of the Amelogenin Locus Typed by AmpFLSTR
Profiler
Plus
Amplification
Kit,”
2(4)
Forensic
Science
Communications (October 2000) (Appendix II, Tab Q).
The study
found "anomalous amplification" in 3 out of 7,600 samples at the
amelogenin (sex typing) locus when Profiler Plus was used. As a
result, the allele for the X chromosome did not amplify, although,
because all 3 anomalies occurred in male samples, they did not lead
to an inconclusive result as to the sex of the contributor. The
study's authors concluded that the most probable explanation for
the anomaly was the presence of a mutation at the primer binding
site.
The study does not suggest that Profiler Plus is not a
reliable method of DNA typing and analysis, or that the primer used
in that particular kit needs to be changed; rather it alerts
analysts to the possibility of such an anomalous, but “rare” result
and cautions that more careful interpretation of the data would be
required when such an anomaly is observed. As a result, analysts
will be able to recognize such an anomaly and take appropriate
steps (such as retesting the sample).
Scientific literature often may identify issues that affect
the use of a scientific method, but that does not mean that the
method itself has become unreliable. For example, phenomena such
as potential contamination, are routinely addressed in laboratory
procedural manuals such as the FBI’s “Short Tandem Repeat Analysis
Protocol” (“FBI Protocols”) (Appendix II, Tab F).
60
Contrary to the defendant’s argument, validation studies have been
made available to the scientific community. This Court should take judicial
notice of the conclusion of the Michigan trial court in Kopp, which, after
reviewing the testimony of several experts, as well as the scientific literature, held
that the “[PCR/STR] methodology and the Perkin Elmer kits [Profiler Plus and
Cofiler] as well as the 310 and 377 Genetic Analyzer have been subjected to a
staggering amount of what can only be called peer review.” Kopp, Op. at 13
(Appendix I, Tab K). Perkin Elmer has described its developmental studies in
numerous public documents and scientific forums; scientists from the FBI’s
research lab have testified that they participated in the developmental studies
with Perkin Elmer scientists; and, numerous laboratories, including the FBI DNAanalysis lab, have conducted internal validation studies comparing the results of
the Perkin Elmer Profiler/Cofiler/310 Analyzer analyses with the results of older,
previously validated systems, and found the results from the Perkin Elmer systems
to be reliable.39/ Moreover, at least three more studies of the Profiler Plus/Cofiler
and 310 Analyzer have been published in peer-reviewed scientific journals.40/
39/
See, e.g., Lynch, at 5 (Appendix I, Tab A)(court-appointed
neutral witness testifies that validation studies of Profiler and
Cofiler kits have been done by scientists at Perkin Elmer, the FBI
DNA lab, and the Virginia and Florida crime labs, all in accordance
with the national quality-assurance standards promulgated by the
DNA Advisory Board); Flores, 12/28/00 Tr. at 162-66 (Appendix I,
Tab G)(summarizing scientific literature in support of reliability
of Perkin Elmer kits); Kirkendahl, Op. at 18-20 (Appendix I, Tab
N)(reviewing various ways in which Perkin Elmer systems had been
61
B.
The general acceptance of DNA typing
methods does not turn on whether the
validated).
40/
Holt, C.L., et al., “TWGDAM Validation of AmpFlSTR PCR
Amplification Kits for Forensic DNA Casework,” 47(1) Journal of
Forensic Sciences 55 (2002) (Appendix II, Tab W) (conducting
validation studies designed as recommended by the TWGDAM guidelines
and DAB standards; studies showed that kits produced consistent and
reliable results); Moretti, T., et al., “Validation of Short Tandem
Repeats (STRs) for Forensic Usage: Performance Testing of
Fluorescent Multiplex STR Systems and Analysis of Authentic and
Simulated Forensic Samples,” 46(3) Journal of Forensic Sciences 647
(2001) (Appendix II, Tab U) (evaluating PCR/STR typing kits from
Promega Corp. and Perkin Elmer; concluding that “commercially
available multiplex kits can be used to amplify and type STR loci
successfully” and that “[t]here was no evidence of false positive
or false negative results”); Moretti, T., et al., “Validation of
STR Typing by Capillary Electrophoresis,” 46(3) Journal of Forensic
Sciences 647 (2001) (Appendix II, Tab V)(concluding that 310
Analyzer “provides efficient separation, resolution, sensitivity
and precision, and the analytical software provides reliable
genotyping of STR loci”).
The Court should reject the defendant’s attempt to discredit
research conducted by FBI scientists (Defendant’s Supplemental
Motion Mot. at 22-23). FBI researchers are widely acknowledged to
be leaders in the field of forensic DNA analysis. Their work in
this area has withstood the scrutiny of scientists around the world
for more than a decade.
A desire by some FBI researchers to
publish more of the results of their research is an understandable
response to arguments, like that of the defendant, that scientific
methods can only be validated by publication in peer-reviewed
journals.
The defendant also seems to misunderstand the peerreview process when he says that FBI examiners are not the “peers”
envisioned by the courts. When FBI researchers submit an article
to a peer-reviewed journal, it must pass an initial peer review by
outside experts before the journal will agree even to publish the
article. Upon publication, the research is open to even further
scrutiny by other scientists.
62
laboratory applying those methods is
subject to blind or open proficiency testing.
The defendant’s complaint about the lack of blind proficiency testing at
the FBI lab may go to weight, but it does not preclude the admissibility of the
DNA evidence. See, e.g., Bridgett, 120 Daily Wash. Law Rptr. 155, at 1704 & n.29;
Porter I, 1991 WL 319015, at * 21-22; see also, Sok, 683 N.E.2d at 681 n.21
(absence of blind proficiency testing not automatic bar to use of DNA
evidence). The FBI laboratory follows the quality-assurance guidelines
promulgated by the DAB, under which its analysts must undergo frequent open
proficiency tests, and the practices of the laboratory have been certified by the
Laboratory Accreditation Board of the American Society of Crime Laboratory
Directors.
Neither the superseded TWGDAM guidelines nor the most current
recommendations of the NRC support the defendant’s assertion that the
acceptance of a DNA-typing technique depends on whether the lab
performing the technique has passed blind proficiency tests. The defendant’s
reliance on TWGDAM rests on two fallacies: that the TWGDAM guidelines were
intended to be mandatory standards for acceptance of DNA typing methods,
and that the guidelines required, rather than expressed a preference for, blind
proficiency tests over open proficiency tests (Defendant’s Supplemental Motion
at 14-18). As previously shown, the TWGDAM guidelines do not impose
mandatory standards for general scientific acceptance. Even if the guidelines
63
were conditions precedent to scientific acceptance, they do not say that blind
proficiency tests are mandatory. See 1991 TWGDAM Guidelines (Appendix II,
Tab G), § 9.2 (“It is highly desirable that the DNA laboratory participate in a blind
proficiency test program, and every effort should be made to implement such a
program.”); NRC II at 79 (“TWGDAM guidelines recommend one full-blind
proficiency test per laboratory per year if such a program can be
implemented”) (emphasis added). That blind proficiency testing may be "highly
desirable" does not mean that its absence renders a laboratory's DNA-typing
results inadmissible.
Nor were the quality-assurance recommendations of the NRC intended to
be an obstacle to findings of scientific acceptance. The thrust of the quality
assurance section of the first NRC report was the urgent need – in 1992 – to
develop reliable standards for forensic DNA typing. Thus, the report
recommended development of national quality assurance standards, frequent
proficiency testing of lab personnel, and monitoring and accreditation by
external organizations. E.g., NRC I at 104-105. In a couple of isolated
statements, the report endorsed blind proficiency testing as the ideal method of
estimating lab error, without any substantive comparison of the benefits and
drawbacks of blind versus open testing. See NRC I at 88, 106. See Bridgett, 120
Daily Wash. L. Rptr. 155, at 1704 n.33 (Court “is not compelled under the Frye
standard to require the ideal but only the generally acceptable”).
64
The second NRC report clarified that the recommendations regarding
quality-assurance standards were just that – policy recommendations – and
strict adherence to those recommendations was not a prerequisite for scientific
acceptance of lab results. See NRC II at 185.41/ In addition, the 1996 NRC
committee found that blind proficiency tests, although seemingly advantageous
in theory, are impractical, and, for that reason, should not be mandatory:
[T]he logistics of constructing fully blind proficiency tests [to ensure
that the forensics laboratory will not suspect that it is being tested]
are formidable. The “evidence” samples have to be submitted
through an investigative agency so as to mimic a real case, and
unless that is done very convincingly, a laboratory might well
suspect it is being tested.
NRC II at 24.42/
41/
The 1996 committee explained that, in the 1992 report, “[w]e
emphasized the importance of minimizing laboratory error . . . .
[However,] [t]hose recommendations rest not on a judgment that
current error rates are so high that test results are
scientifically unacceptable, but on a desire to reduce the
incidence of errors to an extremely low value.” NRC II at 180.
42/
The second NRC committee had the benefit of the preliminary
results of a Congressionally mandated study which concluded that a
widespread policy of blind proficiency testing was unworkable. See
“The United States DNA Advisory Board and Its Role in Setting
Quality Assurance Standards,” Remarks by Arthur J. Eisenberg, 1st
International DNA User’s Conference, November 24-26, 1999, at 2
(National Institute of Justice (“NIJ”) study concluded that “blind
proficiency
tests
via
law
enforcement
agencies,
conduit
laboratories and/or blind analyst models, is not feasible at this
time”) (emphasis in original) (Appendix II, Tab N). The NIJ study
did not, as the defendant mistakenly contends, endorse the use of
blind proficiency tests (Defendant’s Supplemental Motion at 14).
See NRC II at 79-80.
The final 250-page NIJ report, entitled
"Developing Criteria for Model External DNA Proficiency Testing,"
65
The Porter courts anticipated the later conclusions of the NRC, when they
rejected the argument that the admissibility of DNA evidence depended on a
showing that the testing laboratory had complied with certain quality-assurance
standards:
[T]he defendant’s multi-prong arguments regarding proficiency
testing are largely public policy pronouncements which have not
been the basis of any court’s decision regarding the admissibility of
scientific evidence. Simply put, if a new scientific evidence is
generally accepted by the scientific community, whether the
technique which generates it is performed competently is a matter
of weight to be assigned by the jury.
Porter I, 1991 WL 319015, at *22; accord Porter II, 618 A.2d at 636; see also
Bridgett, 120 Wash. Law Rptr. 155, at 1703 n.27 (“[T]he Frye standard does not
require the admission of utopic scientific methodology, but rather generally
accepted scientific
can be accessed at www.uic.edu/pharmacy/depts/forensicsci/.
66
methodology.”).43/ For the same reasons, this Court should reject the
defendant’s complaints regarding blind proficiency testing.44/
43/
Although Judge Kennedy acknowledged in Porter III that the
first NRC report had endorsed the use of blind proficiency tests,
he also recognized the difference between policy recommendations
and factors that affect the scientific acceptance of new methods
under the Frye test. He declined Dr. Eric Lander’s recommendation
that the court decide whether a specific kind of proficiency
testing program was appropriate, saying that “[t]he specific
features of a proficiency testing program are better left to
policymakers, i.e., legislators.” Porter III, 1994 WL 742297, *7.
Accordingly, Judge Kennedy held that he would defer to the
recommendations of the congressionally authorized DNA Advisory
Board. Id. The DAB standards do not mandate blind proficiency
testing.
44/
We address the defendant’s related argument – that the results
of the proficiency tests should be combined with the probability
statistics – in the section on random match probabilities, infra.
67
Even if it were necessary under Frye to demonstrate compliance with a
sound quality assurance program, the FBI has a rigorous program of proficiency
testing that complies fully with the current quality assurance standards issued by
the DAB, which are consistent with the conclusions of the 1996 NRC report.45/
See FBI “DNA Analysis Unit I Quality Assurance Manual” (“Quality Assurance
Manual”) (Appendix II, Tab C). The DAB standards say that “examiners and
other [designated] personnel . . . shall undergo, at regular intervals of not to
exceed 180 days, external proficiency testing . . . [which] shall be an open
proficiency testing program.” See DAB Standards (Appendix II, Tab C), § 13.1.
Consistent with those currently accepted quality control standards, each of the
FBI DNA lab examiners must pass open proficiency tests at least every 180 days.
See Quality Assurance Manual(Appendix II, Tab C), § 17.2.1 . To date, no
examiner has called a match where there was none. In addition, since the
Porter decisions, the FBI DNA analysis lab also has participated in the
accreditation program of, and been accredited by, the Laboratory
Accreditation Board of the American Society of Crime Laboratory Directors. See
45/
The defendant places undue emphasis on the references in the
1992 NRC report to an unusually high number of errors in two blind
proficiency tests conducted at a private California laboratory
(Defendant’s Supplemental Motion at 15-16). The 1996 NRC report,
which had the benefit of several more years of experience with DNA
analysis for forensic purposes, concluded that those errors were
unlikely to be repeated because of increased emphasis on quality
control. NRC II at 86.
68
Certificate of Accreditation, Appendix II, Tab D, and FBI analysts routinely testify
about its accreditation status. Although the Melton “minimal reliability” standard
is not implicated in this case, if it were,” the FBI’s decision not to submit to blind
external proficiency testing does not undermine minimal reliability under
Melton.” (Roberts/Veney Order at 18).
We agree that, although the risk of error in a forensic analysis is not a
factor affecting admissibility, it is a proper subject for a jury to consider when
deciding the weight to be given the results of such analyses. For that reason, FBI
experts routinely testify about the results of recent proficiency tests. That
practice is consistent with what Judge Kennedy expected the DNA expert to do
in Porter III, 1994 WL 742297, *7 n.22 (the government “is prepared to report that
the FBI has made no false matches in its seven blind proficiency tests. This is
acceptable, not misleading, and can be easily understood and evaluated by
the jury.”); id. at *8 (error rate shall be stated by “presentation of expert
testimony that the FBI laboratory has made X errors in Y blind proficiency tests”;
also noting that such a presentation was in accordance with the [1992] NRC
Report). It is also what Judge Richter contemplated in Bridgett. 120 Wash. L.
Rptr 155, at 1703.
C.
The general acceptance of a scientific
method does not turn on whether the
quality assurance standards and protocols
69
for that method are also generally
accepted, or whether the laboratory
applying that method has followed
accepted protocols.
The defendant continues to quarrel with the fact that “[t]here is no basis in
the law of this jurisdiction for holding hostage new scientific evidence which is
“generally” accepted because of the absence of standards.” Porter I, 1991 WL
319015, *28 n.59. Yet they have produced no contrary authority in this
jurisdiction, and, as shown in this opposition, the few cases from other jurisdictions
that arguably hold otherwise are not persuasive. Although the defendant
suggests that this Court does not have to follow Porter I, the trial court’s
reasoning was adopted by the Court of Appeals. The Court of Appeals was well
aware of the Porter trial court’s extensive discussion of the defense argument
that the results of an accepted scientific method could not be admitted
because the government did not show that the laboratory had followed
generally accepted standards and protocols. See Porter I, 1991 WL 319015, *21*22; Porter II, 618 A.2d at 635 & n.9. After noting that the trial court had
addressed this contention, and other contentions, “in considerable detail,” the
Court of Appeals affirmed, “for the reasons stated by the trial court,” the trial
70
court’s conclusion that the RFLP method of DNA analysis was nonetheless
generally accepted. Porter II, 618 A.2d at 635, 636.46/
If the RFLP methods could be found generally accepted in the relevant
scientific community at a time when there were no industry-wide mandatory
quality assurance standards, or wide-spread external accreditation programs, a
fortiori, it is no barrier to a finding of general acceptance that the defendant
thinks that the extensive quality assurance standards created by the DNA
Advisory Board are insufficient. Even if the existence of sufficient standards were
required for a finding of general acceptance, the defendant’s complaints
come down to three issue: 1) the absence of public disclosure of the primer
sequences used in Profiler Plus and Cofiler; 2) the alleged failure to ensure
external validation of the Profiler Plus/Cofiler/310 Analyzer system, and 3) the
46/
One of the other contentions was the closely related
contention that the DNA evidence could not be introduced because
the laboratory had failed to perform the right kind of proficiency
tests. The Porter I trial court reached the same conclusion about
objections to the nature of proficiency tests, as it did about
objections to lack of industry-wide standards.
As with his objections, regarding the absence of uniform
standards,
the
defendant’s
multi-prong
arguments
regarding proficiency testing are largely public police
pronouncements which have not been the basis of any
court’s
decision
regarding
the
admissibility
of
scientific evidence. Simply put, if a new scientific
evidence is generally accepted by the scientific
community, whether the technique which generates it is
performed competently is a matter of weight to be
assigned by the jury. Porter I, 1991 WL 319015, *22;
accord Porter II, 618 A.2d at 635-36.
71
fact that forensic laboratories are not required to undergo blind proficiency
tests. The government has already demonstrated why those arguments do not
undermine the general acceptance of the methods used in this case.
The affidavit of Arthur Eisenberg, former chairperson of the DNA Advisory
Board (DAB), explains that the TWGDAM guidelines, on which the defendant
formerly relied for the position that revelation of primer sequences and
evaluation of laboratory performance by blind proficiency testing were
mandatory, did not intend to make those recommendations a mandatory
requirement for scientific acceptance. Eisenberg Aff. ¶11. He also explains that
the DAB modified those particular provisions because experience and research
indicated that they were no longer advisable. Eisenberg Aff. ¶¶15, 23-28, 33-34.
The DAB was created by Congress to create industry-wide standards for DNA
forensic laboratories. Eisenberg Aff.¶12. It was recognized by the National
Research Council and the Porter III court to be the appropriate body to create
such standards. NRC II at 88; Porter III, 1994 WL 742297 *7 (D.C. Super. Ct. Nov.
17, 1994). Even if it were appropriate for this Court to determine the correctness
of the quality assurance standards applied to forensic laboratories, the
defendant has offered no reason why the Court should substitute the
defendant’s view of sufficient standards for the judgment of the scientists
appointed to the DAB (or those appointed to the NRC Committee on DNA
72
forensic science who believed that the DAB was an appropriate body to
develop such standards).
The FBI maintains detailed quality control and quality assurance
procedures to regulate the performance of forensic PCR and STR typing in its
laboratory. From a quality control standpoint, the FBI has developed a protocol
for performing the PCR amplification and typing of the thirteen core STR loci
using the Profiler Plus and Cofiler amplification kits. Budowle Tr. at A-155; App. II
Tab F.47/ The protocol provides a procedure for performing each stage of the
amplification and typing process, from extracting the samples through the
typing stage. Id. The protocol was developed after research and validation
studies of the technology and methodology by the FBI laboratory research unit,
as well as after internal validation studies by the case working unit. Budowle Tr.
at A-156. Since its development, the FBI has widely disseminated its STR protocol,
including presentations at scientific meetings. Id. at A-157. There do not appear
to be any peer-reviewed scientific publications that have found the FBI protocol
to be unreliable or invalid for use in performing STR typing. Id.
47/
Citations to the expert testimony from the Trala case will be
designated by witness name and page number as indicated in those
original transcripts. The transcripts are bound in two appendices
to the brief; Appendix IV, Part One, and Appendix IV, Part Two.
The dates of the testimony are designated by a letter: May 7 - A;
May 8 - B; May 9 - C; May 10 - D.
73
If one uses properly calibrated instruments and follows the FBI protocol,
one should obtain essentially the same result (within established measurement
error conditions) each time a technique is applied to the same DNA sample.
Budowle Tr. at A-158. That is, while any analytic system will be subject to
measurement error (as well as human errors), if the protocol is followed the
results will have a zero error rate insofar as obtaining a wrong result (i.e., typing
sample “B” as sample “A”) is concerned.48/ Id. at A-158-59.
As for quality assurance, the FBI laboratory maintains a Quality Assurance
Manual for the forensic case working unit, as well as an audit process. Budowle
Tr. at A-159, App. II Tab E. Some of the specific procedures used to ensure
quality assurance and quality control in the laboratory include:
·
·
·
·
·
maintaining separate rooms with dedicated equipment for pre- and
post-amplification samples;
use of hoods and safety sheeting with chemical operations;
use of gloves, masks, and pipettes;
separation of the extraction of the question and reference samples;
use of positive and negative controls in the amplification and typing
process;49/
48/
Measurement errors are common to any analytic system. Take,
for example, the measuring of a person’s height with a ruler. The
same person could be measured at five-eight and one quarter on one
occasion, and measured ay five-eight and three-eighths on another
occasion. Although the results here are different by virtue of
measurement error (assuming the person has not grown), the results
can be considered the same within established tolerance limits for
scientific purposes. Budowle Tr. at A-158.
49/
A positive control is a known sample of DNA that is run in
every PCR reaction; they typing result of the positive control
should be the same every time. Budowle Tr. at A-162. Negative
controls generally contain no DNA in them. When these controls are
74
·
technical peer review and administrative review of case work.
Tr. at A-160-63; D-69.
Thus, even if the Court were required to approve of
admissibility standards before admitting DNA evidence,
the standards followed by the FBI would pass muster.
D. Allegations of interpretive errors in individual
cases go to weight, not admissibility.
1.
The Frye test does not require
proof of adherence to correct
procedures in each particular
case.
run in each reaction, they should show no result at the end of the
process; if they generate results, it indicates the presence of a
contaminant in the reaction. Id. at A-163.
75
It is not the law of this jurisdiction that "the proponent of the DNA
[evidence] must also satisfy and demonstrate adherence to correct scientific
procedures in the particular case at hand" (Defendant’s Supplemental Motion
at 10).50/ The defendant’s reliance on cases from other jurisdictions which apply
such a standard, such as United States v. Two Bulls, 918 F.2d 56 (1990), vacated
on other grounds, 925 F.2d 1127 (8th Cir. 1991), and People v. Castro, 545
N.Y.S.2d (Super. Ct. 1989), is misplaced. The same case authority and argument
was presented to Judge Kennedy in Porter I, but he refused to examine the
reliability of the particular test results in Porter because neither the traditional Frye
50/
The defendant tries mistakenly to derive such a rule from
United States v. Melton, 597 A.2d 892 (1991) (en banc) (Defendant’s
Supplemental Motion at 7). Melton addressed whether a trial court
must find the factual information on which an expert bases her
opinion independently admissible and reliable before allowing
testimony about the opinion. That case involved a psychiatrist's
reliance on hearsay statements from hospital records and the
defendant's family members to opine on the defendant's mental
health. The scientific acceptance of the methods applied by the
expert to those facts was not at issue, so Melton is not a gloss on
the Frye standard.
Nor does that case create an evidentiary
obstacle to the admissibility of the DNA evidence in the instant
case.
Relying on the principles expressed in Federal Rule of
Evidence 703, the Court of Appeals held in Melton that the facts or
data on which an expert witness relies for her opinion do not have
to be independently admissible, so long as they are "of a type
reasonably relied upon by experts in the particular field in
forming opinions or inferences upon the subject."
Id. at 901.
Because this was intended to be a “deferential” standard, id, the
en banc Court overruled the panel's holding that the underlying
information, if not otherwise admissible, must be "of a type for
which the underlying reliability of the data can be sufficiently
explored through cross-examination of the testifying expert." Id.
at 904.
Instead, the en banc Court required only that the
76
test nor precedent in this jurisdiction permitted such an examination.51/ Porter I,
1991 WL 319015, at *18 (holding that many of the defendant's objections to
admissibility were "simply irrelevant, perhaps because of his erroneous equation
of reliability with general acceptance").
The Court of Appeals expressly affirmed Judge Kennedy's understanding
of the law in this jurisdiction, Porter II, 618 A.2d at 634, and emphasized that
“[a]ny failure by the scientists to adhere to the appropriate procedure . . . does
not raise an issue which implicates Frye.” Id. at 636. Given that express holding,
and the Court of Appeals’ admonition in an earlier case that “[t]he answer to
the question about the reliability of a scientific technique or process does not
vary according to the circumstances of each case,” Jones, 548 A.2d at 40, the
suggestion at the end of Porter II that it sometimes might be appropriate to
conduct a pretrial inquiry into how well a procedure was performed must be
read narrowly, and in the context of the state of the art of DNA analysis in 1992.
See 618 A.2d at 644 n.28.
underlying information be of minimal reliability.
51/
Judge Kennedy recognized that, even if a trial court agreed
with the approach taken in Two Bulls and Castro, "trial judges in
this jurisdiction are not permitted to disregard precedent because
of an ad hoc determination that it is 'wrong.'" Porter I, 1991 WL
319015, *16 n.45.
77
The precaution of a pretrial "reliability" hearing on DNA typing might have
been necessary on occasion in 1992, but such precautions are not necessary
today. As Judge Richter has noted, “The world of forensic DNA science has not
remained unchanged since DNA was first admitted in a criminal proceeding. If
anything, DNA science has matured, becoming increasingly familiar, widely
used, powerful, discriminating, and accurate.” (Roberts/Veney Order at 4-5). In
1992, DNA typing for forensic purposes was still relatively new; there was more
variation in the products used to conduct the RFLP typing method; the forensic
community had only begun to develop national quality-assurance standards for
DNA analysis; and forensic laboratories were not routinely accredited in DNA
procedures by external organizations. Examination of the application of
accepted methods in a particular case is unnecessary twelve years later,
especially in cases like the ones before the Court, in which the laboratory has
applied a standardized and widely used PCR/STR system such as the
Profiler/Cofiler/310 Analyzer system; the laboratory adheres to accepted
national quality-assurance standards such as those promulgated by the DNA
Advisory Board; and it is accredited by an outside organization such as the
American Society of Crime Laboratory Directors Laboratory Accreditation
Board.52/ See NRC II at 76-78 (components of high laboratory standards program
52/
The reasoning in Bridgett, 120 Daily Wash. Law Rptr. 155, at
1697, does not compel a different conclusion.
After finding
evidence derived from the RFLP process admissible under Frye, Judge
78
include adherence to quality-assurance guidelines and accreditation by
professional organizations).53/
2.
The defendant’s allegation
that the methodology applied
in this particular case is
unreliable does not
demonstrate deficiencies in
the underlying scientific
methods.
The defendant broadly claims that “The DNA examiner’s methodology in
determining the profiles contained in each sample from the crime scene is
unreliable and, therefore, renders his report of these profiles and his statistical
conclusions inadmissible under Frye/Dyas.” (Defendant’s Supplemental Motion
at 24). First, the defendant fails to articulate any examples of interpretive error
Richter decided to conduct a separate pretrial hearing “to
guarantee that the FBI followed its own procedures in this case.”
Id. at 1703. The Court said that, in the absence of appellate
guidance, it was taking this extra step solely as a prudential
matter, and observed that “the precaution of a pretrial hearing
should not be necessary, once admissibility is more firmly
established.”
Id.
Bridgett was decided before the Court of
Appeals reaffirmed, in Porter II, that how a laboratory performed
the accepted scientific tests was a matter of weight, not
admissibility.
53/
It is conceivable that, in a rare case, a laboratory might
deviate from accepted methods so significantly that the reliability
of the underlying methods is undermined. However, "[a]n allegation
of failure to properly apply a scientific principle should provide
the basis for exclusion of an expert opinion only if ‘a reliable
methodology was so altered . . . as to skew the methodology
itself.’” United States v. Martinez, 3 F.3d 1191, 1198 (8th Cir.
1993)) (citation omitted).
The defendant’s complaints do not
remotely rise to that level.
79
which could lead this court to conclude that the methodology used by this
particular examiner was unreliable. Second, even if the defendant could do so,
“[t]he mere fact that a body of data may be interpreted in two different ways
does not establish a lack of general acceptance of the technique, experiments,
or procedures by which those data were produced.” Whittey, Order at 14, 15
(Appendix I, Tab R) (holding, under Frye test, that such interpretative issues “pose
no bar to the admissibility of PCR-based STR test results”). Challenges to an
analyst's interpretation of data in a particular case are distinguishable from
claims that a particular method or system cannot "repeatedly produce the
same electropherogram from a sample of the same genetic material," id. at 15.
The latter claims may affect admissibility under a Frye or Frye-Plus standard; the
former do not.
Further, to the extent that there is any argument by the defendant that
interpretive errors occurred, he has not identified any expert who would support
the idea that those mistakes undermine the scientific validity of the underlying
methods, or even the weight that a factfinder should give the evidence as a
whole. Because any allegations involving the application of methodology by a
particular lab analyst raise no more than issues concerning the weight to be
given the evidence, and not admissibility issues, they are not the proper subject
of a Frye hearing. Porter II, 618 A.2d at 634, 636; see also Whittey, Order at 14, 15
(Appendix I, Tab R).
80
The defendant also argues that the FBI’s work does not pass muster under
Frye because of problems with a particular analyst, Jacqueline Blake, and an
investigation launched by the U.S. Department of Justice Inspector General
(Defendant’s Supplemental Motion at 1 n.3). Ms Blake was a laboratory biology
technician in one of the FBI Laboratory's two DNA Analysis Units who failed to
perform a step in the standard operating protocol necessary for the detection of
possible contamination that may have been introduced during analysis. She did
not work on this case, and this problem does not extend beyond the work of
that particular technician. Further, that technician's omission alone cannot
cause a false positive result, and there is no evidence to date of a false positive
among that technician's cases. 54/
Specifically, the technician violated the Laboratory's standard operating
protocols by not processing negative control specimens to completion in
approximately 100 cases over a two-year period. Those negative controls
constitute a quality-assurance component of the analytical processing and
reporting of DNA analysis by the method used in the instant case, which involves
Polymerase Chain Reaction (PCR) amplification of Short Tandem Repeats (STR).
There are two such negative controls: one is called a reagent blank, and it is
added to the process at the initial extraction and purification step; the second is
called a negative amplification control, and it is added at the step where the DNA
obtained through extraction and purification is amplified for analysis. The negative
controls function to monitor the PCR/STR process for the possible presence of
contamination.
The FBI Laboratory takes several measures to prevent contamination from being
introduced during the PCR/STR process. The nature of the technician's omission
affects the Laboratory's ability to confirm that contamination was not introduced
during the DNA tests in which that omission occurred. However, even if
contamination was introduced and went undetected in a particular test, it is highly
unlikely that it could cause a false positive result. As stated in the scientific
literature, contamination is more likely to cause inconclusive results, or a false
54/
81
exclusion, than a false positive. The FBI Laboratory is taking steps to address cases
handled by that technician, to include the retesting of evidentiary and known
source materials where possible and appropriate. When retesting in the
technician's cases has taken place and yielded viable results, those new results
have not changed the ultimate conclusions regarding DNA profile inclusions or
exclusions.
82
This matter was referred to the Justice Department's Office of the
Inspector General and resulted in the resignation and subsequent conviction of
hte technician. In addition, since learning of the technician's omissions, the
Laboratory has revised its practices in an effort to detect and prevent such
noncompliance with required protocols.
Of greater importance, the analyst in the instant case has reviewed the
underlying data, previously made available to the defendant in discovery, and
can confirm that the negative controls were run in all of the tests in this case.
Those controls confirmed that no contamination occurred. Thus, any omissions
by Jacqueline Blake in unrelated cases clearly have little or no relevance to the
analysis in this case. Nevertheless, to the extent relevant at all, any arguments
the defendant may make about Jacqueline Blake or the investigation go to the
weight of the evidence, not its admissibility.
VI.
The procedures by which the FBI determines statistical
match probabilities, which include use of the product
rule, are generally accepted by the relevant scientific
community.
Typing and comparison of DNA types at the selected loci are the first part
of forensic DNA analysis. If a match is found, the analyst must next determine
the significance of the match by calculating the coincidental, or random,
match probabilities. The random match probability “essentially expresses the
expected frequency of the observed DNA profile in a pertinent population.”
United States v. Shea, 957 F. Supp. 331, 335 (D. Mass. 1997), aff’d, 159 F.3d 37 (1st
83
Cir. 1997). Our Court of Appeals has held that “the probability of a coincidental
match is an essential part of the DNA evidence,” Porter II, 618 A.2d at 640, and,
therefore, the statistical “procedures for determining a match must pass muster
under Frye.” Id. at 631.
The United States intends to offer expert testimony at trial regarding two
types of DNA evidence that were recovered from the crime scene: (1) “sole
source samples” that comprised blood from a single individual; and (2) “mixture
samples” that contained blood from two or more individuals. With respect to
the sole source samples, the government’s DNA expert will testify that the DNA
profile of blood developed from thirteen sole source evidence samples matches
defendant’s DNA profile, and that the DNA profile of blood developed from
twenty two sole source evidence samples matches decedent’s DNA profile.
Hence, there are a total of thirty five sole source samples.
The government’s DNA expert will also discuss seven mixture samples. In
some of the mixture samples, the FBI analyst will testify that the major contributor
of sample is defendant and decedent can not be excluded as an additional
contributor. Conversely, in other mixtures, the FBI analyst will testify that the
major contributor is the decedent and the defendant can not be excluded as
an additional contributor. Finally, in one mixture, the FBI analyst will testify that
the decedent and defendant are both contributors.
84
Whether the evidence involves a single source sample or an indiscernible
mixed sample, the procedure used by the FBI for calculating the random match
probabilities begins by obtaining, from published tables, the frequencies of the
alleles that were observed at each locus in the DNA profile from the examined
sample. Shea, 957 F. Supp. at 335-36. Through studies of sample population
databases, FBI and other research scientists have previously determined and
published the frequency with which the alleles observed at each of the 13
CODIS loci have been found in the pertinent population. For a sole source DNA
sample, or a mixed sample in which major and minor contributors can be
discerned, or an intimate sample can be subtracted, the frequency of the
genotype at each tested locus, i.e., the frequency with which the observed
maternal and paternal alleles appear together at that locus, is calculated by
established formulas based on a genetic principle known as the HardyWeinberg principle. For a mixed-sample of DNA – one in which there appear to
be two or more contributors and there is no way to distinguish among the
contributors – the FBI essentially adds the frequencies of all the possible
combinations of alleles observed at a locus to obtain a frequency for the
combined genotype at that locus. This approach is consistent with a statistical
technique found acceptable by the NRC. Regardless of the method used to
determine the frequency of a genotype at a particular locus, the frequencies of
the genotypes at all the tested loci are multiplied together to obtain the
85
probability of a random match of the entire DNA profile. This last process is the
product rule.55/
The FBI currently calculates match probabilities according to the methods
approved by the National Research Council in its 1996 report (NRC II), which
involve use of the product rule. See FBI Protocols, at pp. 10-6 to 10-8, Appendix
II, Tab F. The defendant claims that these statistics cannot be admitted in
evidence because the FBI does not incorporate a lab-error rate in its probability
calculations; its use of the product rule is invalid because the databases from
which its allele frequency charts are derived are too small, and use of the rule
does not account for population substructuring; and the method used for mixed
samples is not generally accepted in the relevant scientific community
(Defendant’s Supplemental Motion at 24). The Court should reject these claims
because the FBI’s methods for calculating random match probabilities are
currently accepted by the relevant scientific community, as reflected in the
recommendations of NRC II; that same scientific community has expressly
rejected the defendant’s proposal to include lab-error rates in those
calculations; and, as already shown, the alleged errors in interpreting data go to
the weight of the evidence, not its admissibility. See Porter II, 618 A.2d at 636.
55/
The product rule provides that "if two events are independent
of each other, the probabilities of each occurring can be
multiplied, and the resulting product is the probability of both
events occurring." State v. Link, 25 S.W.3d 136, 144 (Mo. Banc),
cert. denied, 531 U.S. 1040 (2000).
86
A.
Although not admissible twelve years ago,
probability calculations based on the
product rule are now admissible because
the scientific consensus has changed.
The defendant’s arguments about the size of the underlying databases
and the existence of population substructuring were raised over twelve years
ago in opposition to use of the product rule to calculate DNA match
probabilities. Those concerns initially caused some scientists to hesitate to
endorse that method, and that lack of consensus in turn caused our Court of
Appeals to reject use of the unmodified product rule to calculate DNA match
probabilities. See Porter II, 618 A.2d at 636. Scientific opinion has changed
significantly since Porter II, and there is now consensus that the product rule can
be used as the FBI now uses it to calculate reliable estimates of match
probabilities. As Judge Richter has found, “Courts re-visiting the admissibility of
DNA have found that that (sic) the scientific community no longer endorses the
Porter II era safeguards, and accepts the product rule, either unmodified or with
minor adjustments as described in NRC II.” (Roberts/Veney Order at 16). Thus,
this Court can now admit estimates based on those methods.
Reluctance to use the product rule arose primarily because of debate
about the extent to which population “substructuring” existed, and the related
extent to which substructuring could affect the reliability of match probabilities
calculated by the product rule. See Porter II, 618 A.2d at 636-40; Bridgett, 120
Daily Wash. Law Rptr. 155, at 1704 & nn. 18-19; Porter I, 1991 WL 319015, at *2487
*28.56/ That perceived controversy caused the Porter trial court initially to refuse
to admit match probabilities as calculated by the FBI at that time. Porter I, 1991
WL 319015, at *28. Because the court also held that the match statistics were an
essential component of DNA profiling, it excluded the DNA evidence. Id. The
government appealed.
56/
As Judge Kennedy explained,
Substructure refers to distinct groups within a larger
population whose members do not mate randomly with the
rest of the subpopulation, but, rather tend to mate only
with members of their group.
If members of a
subpopulation do not mate randomly with members of the
larger population, that population may be out of HardyWeinberg equilibrium and the frequency with which certain
alleles appear in the population could be different than
the frequency of the same alleles in the subpopulation.
Therefore, a database comprised of alleles from the
larger population and which does not account for the
allele frequency in the subpopulation could lead to an
erroneous estimate of finding a coincidental match
because the DNA of a suspect who is a member of the
subgroup could be compared to the DNA of a population
having genetic attributes different than his.
Porter I, 1991 WL 319015, *10.
88
Between the trial court’s initial ruling and consideration by the Court of
Appeals, the NRC published its first report on forensic DNA typing. That report
acknowledged the debate over the use of the product rule to determine match
probabilities. See NRC I at 80. Without resolving that debate, the report
assumed that population substructuring may exist to a significant degree. Id.
The NRC concluded, however, that the possibility that such problems existed
should not prevent the introduction of DNA evidence because the assumed
deficiencies “may be corrected by ensuring that the probability estimates of a
coincidental match between the evidentiary and known samples are
‘appropriately conservative.’” Porter I, 618 A.2d at 643. NRC I proposed
methods, called the “ceiling principle” and the “interim ceiling principle”, by
which such conservative adjustments could be made.57/ NRC I at 80-85.
Equating the NRC’s “conclusion regarding the proffer of a conservative
method for calculating probability estimates” with “general acceptance of
those methodologies in the relevant scientific community,” Porter II, 618 A.2d at
643 n.26, the Court of Appeals remanded the case back to the trial court to
determine “whether the requisite consensus now exists for a conservative
statement of the probability of a coincidental match and, if so, what the
probability is in the present case.” Id. at 642-43. On remand, the trial court ruled
57/
For an explanation of how the ceiling principles were applied,
see Bridgett, 120 Daily Wash. Law Rptr. 155, at *1704-05.
89
that probabilities derived from the modified ceiling principle recommended by
NRC I would be admissible. Porter III, 1994 WL 742297, *5; see also Bridgett, 120
Daily Wash. Law Rptr. 155, at 1704-05. Those ceiling principles were
acknowledged to place very conservative limits on the probability statistics.
NRC I at 80.
Since 1992, however, the scientific consensus has changed. The relevant
scientific community no longer thinks it is necessary, or appropriate, to impose
such conservative limits on statistics calculated with the product rule. This
change has occurred in part because the PCR-based typing methods can
define the alleles more accurately than the RFLP method, but mostly because
studies have since shown that, to the extent there may be population
substructuring that affects the frequencies with which particular alleles will be
observed, the effect is more modest than originally hypothesized, and the effect
can be compensated for in other ways. As a result, courts that have reexamined this question have concluded that the scientific community no longer
endorses the ceiling principles, but, instead, accepts the product rule, either
unmodified or with certain minor adjustments described in the 1996 NRC report,
as an appropriate method by which to calculate match probabilities in forensic
DNA analysis. See, e.g., People v. Soto, 981 P.2d 958, 976 (Cal. 1999) (collecting
cases).58/
58/
Among the recent decisions finding the unmodified product rule
90
There are at least three reasons why courts have concluded that scientists
no longer think it is necessary to impose artificial ceilings when using the product
rule, either for the older VNTR-based methods of analysis, like the RFLP method in
Porter, or for the current PCR-based methods, like the STR method used in this
case:
to be generally accepted under Frye or Frye-Plus tests are: Soto,
(Frye-Plus); Lindsey v. People, 892 P.2d 281 (Colo. 1995) (Frye),
abrogated on other grounds, People v. Shreck, 22 P.2d 68 (Colo.
2001); People v. Miller, 670 N.E.2d 721 (Ill. 1996) (Frye); People
v. Chandler, 536 N.W.2d 799 (Mich. App. 1995)(Frye); Watts v.
State, 733 So. 2d 214 (Miss. 1999)(Frye-Plus); State v. Freeman,
571 N.W.2d 276 (Neb. 1997)(Frye-Plus); State v. Marcus, 683 A.2d
221 (N.J. Super. Ct. App. 1996) (Frye); Commonwealth v. Blasioli,
713 A.2d 1117 (Pa. 1998); State v. Copeland, 922 P.2d 1304 (Wash.
1996) (Frye); see also State v. Gore, 21 P.3d 262 (Wash. 2001)
(product rule calculations admissible in cases involving PCR-based
tests).
Other cases have found general acceptance of the
unmodified product rule as part of their relevance/reliability test
under a Daubert-like standard. See, e.g., Commonwealth v. Rosier,
685 N.E.2d 739 (Mass. 1997)(finding product rule generally accepted
for RFLP typing case); Taylor v. State, 889 P.2d 319 (Okla.
1995)(product rule passes State’s relevance/reliability test or
Frye); see also Commonwealth v. Sok, 683 N.E.2d 671 (Mass.
1997)(relying on Rosier; product rule admissible in PCR case).
91
First, in 1993, the FBI conducted a survey of VNTR frequency data
and determined that population frequency calculations based on
the product rule were “reliable, valid and meaningful, without
forensically significant consequences resulting from population
substructure as had been postulated by some scientists.”59/ . . .
[Second, b]ased on the FBI study, Dr. Eric Lander, the leading
opponent in the scientific community to use of the product rule,
declared that the “DNA fingerprinting wars are over”60/ . . .
59/
See Laboratory Division, Federal Bureau of Investigation,
United States Department of Justice, VNTR Population Data: A
Worldwide Study 2 (Feb. 1993) (“FBI VNTR study”). The conclusions
of the VNTR study are summarized in Copeland, 922 P.2d at 1318-19.
In addition to the FBI study, courts have relied on “extensive
literature in peer-reviewed journals . . . [that] supports the
premise that [population] substructuring does not impact
significantly upon DNA population frequency estimates.” Soto, 981
P.2d at 976-77 (collecting cases); accord Blasioli, 713 A.2d at
1125-26; Copeland, 922 P.2d at 1319 (citing scientific journals).
60/
See E. Lander & B. Budowle, “DNA Fingerprinting Dispute Laid
to Rest,” 371 Nature 735 (Oct. 27, 1994) (hereafter, “Lander &
Budowle, ‘Dispute Laid to Rest’”) (see Appendix II, Tab J). Many
courts found it significant that Dr. Eric Lander, a critic of the
product rule who was one of the authors of the 1992 NRC report that
recommended the ceiling methods, had changed his mind. In his 1994
article, Dr. Lander, and his co-author Dr. Bruce Budowle, said that
NRC I “failed to state clearly enough that the ceiling principle
was intended as an ultra-conservative calculation, which did not
bar experts from providing their own ‘best estimates’ based on the
product rule.” Lander & Budowle, at 737. They also concluded that
the FBI’s population surveys
yielded a remarkable database for examining allele
frequency variation among ethnic groups. Reassuringly,
the observed variation is modest for the loci used in
forensic analysis and random matches are quite rare,
supporting the notion that the FBI’s implementation of
the product rule is a reasonable best estimate.
Lander & Budowle, at 738.
92
Finally, in its 1996 Report [NRC II], . . . , the NRC noted “‘[t]he ceiling
principles were intended for VNTRs with many alleles, no one of
which has a very high frequency [and the ceiling principles] are not
applicable to PCR-based systems.’” The 1996 Report concluded
that both the ceiling and the interim ceiling principles were
unnecessary and “‘[i]n general, the calculation of a profile
frequency should be made with the product rule,’” both for VNTR
and PCR-based systems.
Watts v. State, 733 So. 2d 214, 225-26 (Miss. 1999)(internal citations omitted). See
NRC II at 5. Accord Soto, 981 P.2d at 975-76 (Frye-Plus; RFLP); Commonwealth v.
Rosier, 685 N.E.2d 739, 745 (Mass. 1997)(modified Daubert test; RFLP; based on
same authorities, concluding that “the controversy has been resolved in large
part”); State v. Freeman, 571 N.W.2d 276, 291-93 (Neb. 1997) (Frye test; RFLP;
relying on Lander & Budowle article, NRC II, and expert testimony);
Commonwealth v. Blasioli, 713 A.2d 1117, 1125-26 (Pa. 1998)(Frye; RFLP; relying
on FBI VNTR study, Lander & Budowle article, NRC II); State v. Copeland, 922
P.2d 1304, 1318-1319 (Wash. 1996)(Frye; RFLP; relying on FBI VNTR study, Lander &
Budowle article, and pre-publication copy of NRC II; “use of the product rule in
establishing statistical probabilities of a genetic profile frequency in the human
population is generally accepted within the relevant scientific community and . .
. a significant dispute no longer exists on this matter”); cf. United States v. Lowe,
954 F. Supp. 401, 418-19 (D. Mass. 1997) (Daubert test; upholding admissibility of
probabilities based on product rule where there was statistical independence
among the loci examined by PCR-based processes (DQ-Alpha, Polymarker, and
93
D1S80)). Thus, the concerns that may have precluded scientific consensus over
use of the product rule when Porter II was decided were resolved shortly
thereafter, and it is no longer necessary to apply the ceiling principle when
calculating random match probabilities.61/
Although the Court of Appeals in Porter II did not find a scientific
consensus in favor of the unmodified product rule in 1992, that conclusion does
not prevent this Court from deciding whether, in view of the advances in
scientific knowledge since 1992, the product rule has now achieved scientific
acceptance. The DCCA did not rule as a matter of law that the ceiling
principles must be used indefinitely. The Court merely held that, when Porter II
was decided, there did not yet appear to be a scientific consensus regarding
use of the product rule for forensic DNA analysis purposes and, therefore, as
required by Frye, evidence calculated using that rule was not yet admissible.
61/
As a result of the NRC’s conclusions in 1996, even the few
remaining critics of the product rule “expressly concede [that] the
product rule/population substructure issue has indeed been laid to
rest.” Soto, 981 P.2d at 976. The Soto court was referring to
concessions by two law professors who often testify as experts in
opposition to DNA evidence: William Thompson and Richard Lempert.
See Thompson, “Accepting Lower Standards: The National Research
Council’s Second Report on Forensic DNA Evidence,” 37 Jurimetrics
405, 423 (noting that population structure studies have “tipped the
balance of scientific opinion in favor of the product rule (or
something close to it)”); Lempert, “After the DNA Wars:
Skirmishing With NRC II,” 37 Jurimetrics 439, 455 (lack of HardyWeinberg and linkage equilibria “seems hardly to matter. Empirical
studies suggest that conservatism in estimating allele frequencies
in the first instance can more than make up for any prejudice an
accused suffers from the untenability of the assumptions.”).
94
Porter II, 618 A.2d at 631. It would be contrary to the intent of Frye, and to the
Court of Appeals’ express reluctance to withhold relevant information from the
jury, see 618 A.2d at 640-42, to interpret the 1992 Porter decision as freezing the
law in perpetuity.
Other courts that initially rejected the product rule under a Frye or FryePlus standard have since concluded, first, that they are not barred by stare
decisis from deciding whether the product rule is now an acceptable method
by which to calculate match probabilities, and, second, that the scientific
community has now accepted use of the product rule for that purpose. See
Freeman, 571 N.W.2d at 293 (Frye-Plus jurisdiction; overruling prior decision that,
relying on NRC I, required use of ceiling principles; “[S]cientific opinion on a
particular scientific matter is not static, and therefore, a determination of
whether a particular type of novel scientific evidence is or is not generally
accepted within the scientific community must consider the current state of the
science.”); Dishmon, Order at 18-19 (Appendix I, Tab O)(Frye-Plus jurisdiction;
concluding that prior state supreme court decision approving use of interim
ceiling method was not stare decisis; 1996 NRC II report finding interim ceiling
method unnecessary and approving use of product rule “represents the best
scientific thinking of the scientific community on the subject,” and thus product
rule meets the Frye test as applied in Minnesota); accord, Kirkendahl, Order at
34-35 (Appendix I, Tab N)(Minnesota Frye-Plus test; 1996 NRC II report represents
95
current consensus among scientists). For the same reasons, this Court should
conclude that match probabilities calculated with the product rule are now
admissible.
B.
The FBI calculates probability statistics for
single-source evidence samples by
methods found acceptable by the
National Research Council.
The Court should admit the probability statistics developed by the FBI
analyst pertaining to the thirteen sole source evidence samples that match the
DNA profile of the defendant and the twenty two sole source evidence samples
that match the DNA profile of the decedent. The formula the analyst applied is
generally accepted as a reliable formula to apply to a single source profile.
In place of the ceiling principles, “‘[t]he [NRC] now recommends the use
of a modified version of the product rule which assumes the existence of some
undetected population substructure of a lesser magnitude than that reflected
by use of the ceiling principle.’” Blasioli, 713 A.2d at 1125 (internal citation
omitted). The minor modifications recommended by NRC II appear in
Recommendation 4.1. See NRC II at 5. As stated in its protocols for STR typing,
the FBI routinely applies the modifications recommended by NRC II when it
calculates match probabilities for single-source or major contributor samples.
See FBI Protocols (Appendix II, Tab F), at pp. 10-6 to 10-8.
96
The FBI uses the modified random match probability (RMP) formula
specified in NRC Recommendation 4.1 for single-source DNA profiles. See NRC II
(App. II, Tab A) at 122. As noted, the basic methodology in that formula is
premised on the product rule. Id. at A-178. In essence, the statistical frequency
of the DNA profile at issue is calculated by multiplying the frequency of each of
the alleles in the profile, and then correcting the result to account for inbreeding
or substructuring effects in the population, as well as applying additional
statistical qualifications. Id. at A-178; Chakraborty Tr. at D-104-05. The profile
frequency that emerges from these corrections/qualifications is more
conservative than would be obtained by use of the strict product rule.
Chakraborty Tr. at D-106, 108.
The NRC/FBI formula includes several conservative features to address
substructuring or inbreeding. The first is the inclusion of a value denoted by the
variable “theta.” Budowle Tr. at A-176; Conneally Aff. ¶8A. The degree of
inbreeding in a given population can be calculated by empirical population
studies. Budowle Tr. at A-167. As a result of such research, the NRC
recommended a theta of .01 for all but the most isolated populations (in which
case a value of .03 is recommended). See NRC II at 122.62/ The FBI laboratory
62/
The method of statistical analysis described above is not new
to STR analysis, and was used in essentially the same manner with
RFLP analysis of VNTRs.
Budowle Tr. at A-186-87.
Indeed, the
concept of the theta inbreeding coefficient correction has been in
use since the 1950s. Id. at A-187.
97
follows this recommendation, despite the fact that the weight of the current
empirical research on various world populations suggests that the actual
observed value of theta is well below .01, rendering the NRC II recommendation
highly conservative. Id. at A-176-77, Chakraborty Tr. at D-109-114; Conneally
¶8A.63/ In addition, the NRC/FBI formula does not use the actual allelic
frequencies for certain alleles that are very uncommon in the database.
Chakraborty Tr. at D-106; Conneally Aff. ¶8A. In other words, if the actual
frequency for a particular allele is below a particular threshold, the formula
requires the analyst to assign that allele a higher, and thus, a more conservative,
frequency for purposes of the calculations. Id. The FBI’s allelic frequency tables
incorporate this “floor.” Conneally Aff. ¶ 8A.
63/
The defendant’s expert in Trala, Dr. Shields, advocates use of
a theta value of .05, but his is a minority view that was first
presented to the 1992 NRC committee. Tr. at D-26-27. The 1996 NRC
report saw no need to adopt such a theta value. Tr. D-27-28.
98
The NRC also recommended that a tenfold tolerance limit be applied to
statistical estimates based on the RMP formula. NRC II at 27; Conneally Aff. ¶8A.
Application of such a “factor-of-ten” adjustment to an RMP of 1 in 100,000
would result in a margin of uncertainty from 1 in 100,000 to 1 in 10,ooo,ooo.
Conneally Aff. ¶8A. This adjustment corrects for genetic or sampling variation
that might occur. Conneally Aff. ¶8A. It generally conveys to the jury a more
conservative result (i.e., one that overstates the actual frequency). Budowle Tr.
at A-185. In the past, the FBI routinely applied that limit to its RMP estimates.
Id.at A-185. That practice is apparently no longer routine; however, on direct
examination, the government will ask the FBI analyst to apply that factor of ten
adjustment, after he reports the raw probability estimates.64/
Because the FBI applies the NRC’s recommended formula for calculating
random match probability estimates for single-source DNA profiles, and the
NRC’s views are the equivalent of general acceptance, the Court should admit
the sole source sample probability estimates.
64/
Even if the prosecutor forgets to ask the analyst to apply
that adjustment, the analyst will give the same answer on crossexamination.
99
The modifications to the random match probability formula contained in
NRC Recommendation 4.1 are appropriate if the underlying databases appear
to be in Hardy-Weinberg and linkage equilibrium, or the deviations from HardyWeinberg or linkage equilibrium are not statistically significant.65/ The FBI
typically reports random match probabilities derived from four databases that
represent the major population groups in the United States: Caucasian, Black,
Southeastern Hispanic, and Southwestern Hispanic.66/ Each of these major
databases contains approximately 200 samples.67/ The frequency of the
occurrence in each database of each allele at each tested locus has been
65/
“Hardy-Weinberg equilibrium . . . means that one allele at a
locus is not predictive of the other allele at that locus . . .
Hardy-Weinberg equilibrium depends upon an assumption of a large
population in which there is random mating.” Copeland, 922 P.2d at
1317 (internal citations omitted). “[L]inkage equilibrium . . .
means that the alleles at different loci are inherited independent
of each other.” Id.
66/
Analysts will refer to other databases if the circumstances of
a case suggest that a population subgroup (e.g., Apache,
Vietnamese, Caribbean) should be considered in addition to the
major groups.
67/
"These [STR] databases contain more than a statistically
sufficient number of samples to permit the calculations of valid
allelic frequencies." United States v. Trala, 162 F. Supp. 2d 336,
351 n.15 (D. Del. 2001) (noting also that FBI has published up to
41 of these databases and made the underlying raw data publically
available). See Budowle, B., et al., “CODIS STR Loci Data from 41
Sample Populations,” 46(3) Journal of Forensic Sciences 453 (2001)
(Appendix II, Tab T). See also State v. Salmon, ___ S.W.3d ___,
2002 WL 31245217, *5 (Mo. App. 2002) (Dr. Kenneth Kidd, professor
of genetics at the Yale School of Medicine, testified that "it was
a generally accepted practice in the forensic science community to
use the FBI database" to calculate random match probabilities).
100
compared with worldwide data compiled by the FBI and with data from other
laboratories’ databases. These studies amply demonstrate the acceptability of
the use of the FBI's databases to determine allele frequencies, and the use of
the product rule to calculate match probabilities from those frequencies.68/
These databases contain a more than statistically sufficient number of samples
to permit the calculations of valid allelic frequencies at the thirteen core STR
loci. Chakraborty Tr. at D-129, 166; Conneally Aff. ¶11.69/
68/
See, e.g., Holt, C., et al., “Practical applications of
genotypic surveys for forensic STR testing,” 112 Forensic Science
International 91 (2000)(concluding that reliable multilocus profile
estimates can be obtained by applying product rule to genotype
frequencies at the 13 CODIS loci) (Appendix II, Tab R); Budowle,
B., et al., “Population Data on the Thirteen CODIS Core Short
Tandem Repeat Loci in African Americans, U.S. Caucasians,
Hispanics, Bahamians, Jamaicans, and Trinidadians,” 44(6) Journal
of Forensic Sciences 1285 (1999)(concluding that the application of
the product rule is valid for estimating the rarity of a multiple
loci profile for the 13 CODIS loci) (Appendix II, Tab M); Lins,
A.M., et al., “Development and Population Study of an Eight-Locus
Short Tandem Repeat (STR) Multiplex System,” 43(6) Journal of
Forensic Sciences 1168 (1998)(concluding that the application of
the product rule is appropriate for estimating the rarity of a
PowerPlex profile, which examines eight of the loci examined by
Profiler Plus)(Appendix II, Tab L); Budowle, B., et al., “United
States Population Data on the Multiplex Short Tandem Repeat Loci –
HUMTHO1, TPOX, and CSF1PO – and the Variable Number Tandem Repeat
Locus
D1S80,”
42(5)
Journal
of
Forensic
Sciences
846
(1997)(concluding that the application of the product rule is
appropriate for estimating the rarity of a multiple loci profile
for these four loci, three of which are incorporated in Profiler
Plus) (Appendix II, Tab K);.
69/
The fact that the databases are convenience samples rather
that true random samples does not affect their validity.
See
Conneally Aff. ¶10; NRC II 30, 126-27.
101
The FBI has published up to 41 of these databases, and has placed all the
underlying raw data on the Internet for public review. Budowle Tr. at A-172-73;
App. II, Tab T. Since the time that this data was placed on the Internet, the FBI is
unaware of any peer-reviewed scientific articles critical of the databases or
suggesting that the databases are insufficient. Budowle Tr. at A-173; see also
Conneally Aff. ¶15.
Empirical research in peer-reviewed scientific journals has demonstrated
that the population data used by the FBI to calculate allelic frequencies meets
the statistical expectations - Hardy-Weinberg and linkage equilibrium underlying the formulas recommended by NRC II to generate a final profile
frequency.70/ See Conneally Aff. ¶10. In particular, a recent study in the peerreviewed scientific journal Electrophoresis demonstrates that the thirteen core
loci tested in this case could even be multiplied together using the strict (i.e.,
unmodified) product rule with statistically reliable results. Chakraborty Tr. at D116.
70/
Empirical research has demonstrated that there are sporadic
departures from the statistical assumptions of independence
underlying the use of the modified product rule for specific pairs
of loci in specific databases. Chakraborty Tr. at D-124. However,
the number of occurrences of such deviations is below the nominal
level of statistical significance. Id. at D-123-24. As a result,
even with these sporadic deviations, the thirteen core loci are
sufficiently independent to allow for the use of the modified
product rule. Id. at D-125.
102
The defendant contends that the FBI’s databases are improperly
structured along racial lines, and that this is an ineffective way to account for
population substructuring (Defendant’s Supplemental Motion at 25-26). The FBI
does not rely on its database categories to compensate for possible
substructuring. As shown above, the RMP formula used by the FBI contains its
own provisions to account for possible substructuring. The FBI maintains separate
databases for different population groups because empirical research still
suggests that, for purposes of forensic identification by DNA analysis, there is
some observable difference in allelic frequency rates between populations,
although it is widely understood that the greatest degree of genetic difference
will be lower within large population groups. Conneally ¶12. A simple
examination of the FBI’s allelic frequency charts, App. II, Tab F, at 10-9 to 10-24,
and the results of the probability calculations in this case reveals that there are
still observable differences between larger populations.
Nothing the defendant has presented demonstrates that the probability
formulas endorsed by the NRC are no longer generally accepted in the relevant
scientific community, or that those formulas should not have been used in these
cases. The Court should therefore admit the evidence and the accompanying
probability statistics.
Moreover, the defendant’s suggestion that the interpretation of mixed
samples is “mired in controversy” (Defendant’s Supplemental Motion at 26-27) is
103
unfounded. He relies solely on an abstract that discusses some of the issues that
arise in the interpretation of DNA from mixed samples, that that reliance is
misplaced (see Defendant Supplemental Motion at 26-27). The cited article
describes several ways in which such complex mixtures can be assessed, but it
nowhere suggests that any of the approaches that it describes is scientifically
unacceptable. See Ladd, C., et al., “Interpretation of Complex Forensic DNA
Mixtures,” 42(3) Croatian Medical Journal 244 (2001) (Appendix II, Tab S); see
also Testimony of Frederick Bieber in State v. Roman Nose (Government
Appendix VI, Tab B)(Dr. Bieber, a co-author of the Croatian Medical Journal
article, explains that FBI methods are generally accepted).71/ Moreover, the
71/
Dr. Bieber is an Associate Professor of Pathology at Harvard
Medical School who teaches mdical students, graduate students,
post-doctoral fellows, and medical residents and interns, and
directs two hospital laboratories that perform diagnostic genetic
testing. He holds a Ph.D. in human genetics, and completed a postdoctoral fellowship in medical genetics. Among other pforessional
affiliations, he is a member of the American Society of Human
Genetics, the American Board of Medical Genetics, and the American
Academy of Forensic Sciences, and he was appointed to the
Congressionally-mandated DNA Advisory Board (“DAB”). Of particular
significance to this case, Dr. Bieber was a co-author of the
article “Interpretation of Complex Forensic DNA Mixtures” on which
the defendant relies for the proposition that there is no consensus
on an acceptable method by which to interpret mixed DNA samples.
Dr. Bieber explains in his testimony that the challenges involved
in interpreting mixed samples do not undermine the reliability of
DNA typing by PCR/STR methods, or evidence a general inability on
the part of DNA analysts to accurately interpret mixed samples,
including, in appropriate circumstances, the ability to discern
individual DNA profiles from mixed DNA samples as was done in one
of the samples in this case (see, e.g., 10/28/02 Tr. 122-136). Dr.
Bieber also testified that the random match probability formulas
104
DNA Advisory Board, which represented a cross-section of experts in the field of
DNA typing, concluded that two of the methods discussed in the Ladd article –
the "combined probability of exclusion" (which is a different way of stating the
probability of inclusion figure calculated by the FBI), and the likelihood ratio
were equally accepted ways of expressing the probative value of DNA
evidence. See DNA Advisory Board, “Statistical and Population Genetics Issues
Affecting the Evaluation of the Frequency of Occurrence of DNA Profiles
Calculated From Pertinent Population Database(s),” 2(3) Forensic Science
Communications (July 2000) (Appendix II, Tab O).
In addition, because of the very low match probability estimates in this
case, the Court should permit the analyst to testify to his opinion that, to a
reasonable degree of scientific certainty, the defendant is the source of the
DNA found on thirteen sole source evidence samples and that the decedent is
the source of the DNA found on thirteen sole source evidence samples.
Under certain statistical circumstances, there is a point at which it would
be scientifically reasonable to attribute the source of a given DNA sample to an
recommended by the NRC II report were generally accepted methods
for calculating match probabilities for single-source DNA samples,
or individual DNA profiles derived from some mixed DNA samples;
that either probabilities of exclusion or likelihood ratios were
acceptable methods for expressing match probabilities for mixed
samples; and that error rates did not have to be included with
probability statistics for those statistics to be acceptable
(10/28/02 Tr. 62-66, 137-166, 168-171).
105
individual. NRC II at 136-37; Budowle Tr. at A-193. In particular, given a
confidence level of 99 percent, and given the current United States population
of 280 million, one can reach a source attribution conclusion to a reasonable
degree of scientific certainty if the profile frequency of the ostensible source and
the matching unknown sample is smaller than one in 280 billion. Tr. at A-195.
The FBI has adopted this formula for reaching source attribution conclusions. Id.
The probability statistics for all thirty five sole sourse evidence samples (13
matching the defendant; and 22 matching the decedent) in this case met the
source attribution threshold.
The NRC II committee concluded that source attribution was appropriate
when the RMP was low enough. It elected, nonetheless, not to recommend any
particular approach to determining the precise point at which the RMP would
be low enough to permit source attribution, leaving that issue to the courts. NRC
II at 136-37. It did, however, describe two methods for setting thresholds that
would allow an analyst to make such an attribution. When the DAB
reconsidered the issue, it concluded that, because DNA typing methods were
able to type such a high number of genetic markers, the magnitude of random
match probability estimates "has approached the point where it is unlikely that
two unrelated individuals carry the same type." Budowle, et al., Source
Attribution of a Forensic DNA Profile, App. II, Tab P. The DAB sought to develop a
106
formula to act as an objective measure by which an analyst could determine
when it was appropriate to make such an attribution. Id.
Although there has been debate over the DAB's recommendations, that
debate has not been over whether it ever can be appropriate to attribute a
source, but what is the best formulation for deciding when to reach such a
conclusion.72/ The FBI’s formulation is generally more conservative than other
approaches presented in the scientific literature. Budowle Tr. at C-36. In fact,
the FBI’s source attribution formula has been described by Dr. James Crow,
chair of the National Commission on the Future of DNA Evidence Research and
Development Working Group, and a leading expert in the field of genetics, as
“a very sensible one.” Tr. at D-10,11. As a result of the conservative approach
taken by the FBI, Dr. Crow further concluded:
So I think almost anybody would agree that [the FBI source attribution
formula] is a procedure that is safe in the sense it would be very, very
rarely would you make the mistake in the wrong direction; that is, in the
direction of wrongly convicting an innocent person. . . . And I guess we’ll
have to ultimately take the position, I would myself at least, that the FBI’s
procedure is the right thing to do. I’m happy to say that the DAB [DNA
Advisory Board] said the same thing.
72/
Even the defendant’s expert in the Trala case agreed that one
can make a source attribution under appropriate circumstances.
Shields Tr. at D-22.
107
Tr. at D-12-13 (emphasis added). The Commission’s final report, moreover, states
that a “high degree of confidence” can be obtained in these source attribution
conclusions. Tr. at C-106.
The DAB adopted a source attribution formula much like one
recommended by the NRC as valid for that purpose. Like the NRC, the DAB
represented a cross-section of the relevant scientific community. Its views on the
source attribution issue may fairly be equated with the views of the relevant
scientific community. Accordingly, the Court should allow the analyst in this
case to report a source attribution.
C.
The FBI’s method for calculating combined
probabilities for mixed sample DNA profiles
is generally accepted.
When the analyst calculated the match probabilities for INSERT # of the
mixed evidence samples as though he had no information about possible
contributors, he used a formula known as the combined probability of inclusion
(“CPI”). The CPI formula is inherently very conservative because it does not
consider how many contributors are present in the unknown DNA samples
based on other reliable information. Conneally Aff. ¶8B. Instead, the formula
creates a frequency profile for each locus based on all the possible
combinations of all the alleles actually observed at that locus. Whether there
were two contributors or a dozen, makes absolutely no difference to the result.
This ordinarily causes the combined frequency at each locus to be much higher
108
and, thus, much more favorable to a defendant than it would be if the
frequency were determined by the RMP formula appropriately used for single
source or major contributor profiles, which essentially multiplies alleles together.
Whether the CPI or RMP formula is used to determine the frequency at each
locus, after the combined allele frequency is determined for each of the tested
loci, the product rule is used to calculate the frequency of the entire DNA
profile, that is, the combined allele frequencies for each of the tested loci are
multiplied together to determine the match probability for the entire DNA profile.
The 1992 NRC committee expressly advocated the use of the combined
probability of exclusion (CPE) formula (NRC I at 59), which is based on the same
mathematical principle as the combined probability of inclusion (CPI) formula
used by the FBI. The 1996 NRC committee preferred a different approach – the
likelihood ratio – but it did not conclude that the CPE/CPI was an invalid
method. NRC II at 129-130. Instead, the NRC II report said that the CPE/CPI
approach was “hard to justify because it does not make use of some of the
information available,” i.e., the genotype of the suspect. NRC at 130.
The scientific community had another opportunity to examine the
formulas that could be used to apply to mixed samples through the work of the
DNA Advisory Board (DAB). Although defendant disparages the DAB,
suggesting that it was a pawn for the FBI, that suggestion has no basis in fact. Dr.
Arthur Eisenberg, who was the second chairman of the DAB, explains that,
109
although the Director of the FBI made the final selection of members, Congress
ensured that the Board represented a broad and independent cross-section of
the relevant scientific community by specifying the fields from which the
members were selected, and by limiting the Director’s choice of members to
persons nominated by the National Academy of Sciences, and professional
organizations. Eisenberg Aff. ¶14. DAB members were wholly independent from
the FBI. Eisenberg Aff. ¶14. The only control the Director had over the final
recommendations of the DAB was his ability to veto them; but he did not do so.
Eisenberg Aff. ¶¶14, 16. Because the membership of the DAB was diverse, and it
actively solicited the views of the scientific community, Eisenberg Aff. ¶14, it is
reasonable to treat its recommendations as reflecting a consensus within the
scientific community familiar with DNA forensic analysis.
The DAB affirmed that both the CPE/CPI and LR methods were
acceptable methods to apply to mixed samples. See App. II, Tab O, at 5. It
pointed out that the PE calculation “is particularly useful in complex mixtures,
because it requires no assumptions about the identity or number of contributors.”
Id. As Dr. Conneally observes, the choice of method depends more on policy
considerations than scientific validity, because both formulas are accepted.
Conneally ¶8B. The policy advantage of the CPE/CPI formula is that it is much
simpler to calculate, and to express correctly to a jury. Id. The authors of the
survey article about interpretation of complex mixtures, on which defendants
110
rely for many of their arguments, speak favorably of the CPE/CPI approach,
saying that it “provides a straightforward, conservative, yet still highly informative
calculation that avoids potential pitfalls associated with extrapolating the
genotypes of contributors.” See App. II, Tab S, at 245. In contrast, the authors
conclude that “[S]ome LR calculations and interpretations can be complicated,
and their significance to the case may not be apparent to the practitioner and
the trier of fact.” Id.
Based on the acceptance of the CPE/CPI formula by the NRC
committees, its endorsement by the DAB, and the inherently conservative nature
of the CPE formula, this Court should admit the CPI probability statistics
calculated by the analyst in this case.
D.
Inclusion of error rates in probability statistics is
unacceptable in the relevant scientific community,
and therefore not required under Frye.
The court should reject the defendant’s contention that “the FBI must
disclose its error rate information or limit its proffered random match probability
by the effect of an estimated error rate using the confidence interval”
(Defendant’s Supplemental Motion at 20). This is another issue that is not
properly before the Court because, in the District of Columbia, laboratory error is
an issue going to the weight of scientific evidence, not to its admissibility, see
111
Porter II, 618 A.2d at 636, a distinction that the defendant repeatedly ignores.
Accordingly, this argument should be rejected without further consideration.
Even if lab error were a proper subject for a Frye inquiry, the defendant’s
proposals must be rejected because they are contrary to scientific opinion:
“General acceptance does not require including error rate in probability
calculations. The scientific community has rejected using error rates to temper
the probability calculations.” (Roberts/Veney Order at 17). The NRC, whose
views are treated by our courts as representative of scientific consensus on DNA
issues, has expressly rejected the notion that error rates should be estimated from
the results of periodic proficiency testing, or that estimates of error rates should
be used to limit the random match probability numbers.
The first NRC report concluded that “[c]oincidental identity and laboratory
error are different phenomena, so the two cannot and should not be combined
in a single estimate.” NRC I at 88. The second NRC report also explicitly rejected
the idea that laboratory error rate was an appropriate component of the match
probability calculations, or even that something approaching a rate of error
could be reliably determined:
The committee offers these recommendations to improve
laboratory performance rather than to try to estimate the
probability that a particular laboratory makes a mistake by
reporting that two DNA profiles match when in fact they do not
match. Auditing and proficiency testing cannot be expected to
give a meaningful estimate of the probability that a particular
laboratory has made such an error in a specific case. An
unrealistically large number of proficiency tests would be needed
112
to estimate accurately even an historical error rate. For such
reasons, proficiency test results should not be combined with the
estimated frequency of an incriminating profile to yield the
probability that a laboratory would report that DNA from a person
selected at random contains the incriminating profile. No amount
of effort and improved technology can reduce the error rate to
zero, and the best protection a wrongly implicated, innocent
person has is the opportunity for an independent retest.
NRC II at 4 (emphasis added). See also id. at 24-25 (proposal to combine error
rates and probability statistics is “ill-advised”).
Because of this strong scientific opposition, courts that have considered
the defendant’s argument have rejected it. See, e.g., Shea, 957 F. Supp. at 340,
344 (proposal for combining error rates with match probabilities is “seriously
flawed because it would deprive the jury of the opportunity to determine the
probability of a false match based on all of the evidence”); Copeland, 922 P.2d
at 1320 (error rate not appropriately part of probability calculations); Kirkendahl,
Order at 35-36 (Appendix I, Tab N)(rejecting Dr. Lawrence Mueller’s proposal to
combine error rates and probability statistics because the NRC II called it “illadvised”); Dishmon, Order at xiii (Appendix I, Tab O)(same; adding that “no
court decision from any jurisdiction in the United States adopting this method
could be found”).73/
73/
Even the few courts that have been sympathetic to the
defendant’s other arguments have rejected the notion that lab error
rates must be included in order to make probability calculations
admissible.
There is no need to calculate the lab error rate along
113
Thus, neither the NRC nor courts in other jurisdictions have required laberror rates to be included in probability calculations. Nor have any courts in the
District of Columbia imposed such a requirement, although, in an abundance of
caution, two of our trial courts have required that information about the results of
proficiency tests be given during testimony about DNA test results. See Porter III,
1994 WL 742297, at *8; Bridgett, 120 Daily Wash. Law Rptr. 155, at 1704. Although
the results of proficiency tests are not relevant to a Frye inquiry, we recognize
that how well a lab performs generally accepted methods is a matter that the
jury is entitled to consider. Porter II, 618 A.2d at 636. Accordingly, the FBI analyst
who testifies at trial in this case will be prepared to address the forensic lab’s
recent practices and experiences with proficiency tests. There is no need to
address those issues before trial.
Finally, the defendant also claims that, regardless of the scientific
acceptance of the FBI's method for calculating probability statistics, the random
match probabilities must be excluded because they are substantially more
prejudicial than probative (Defendant’s Supplemental Motion at 27). That
with the likelihood ratio from DNA analysis. Our system
does not calculate lab error rates in any other forensic
evidence effort. To include the two together disregards
the empirical nature of scientific evidence. . . . Use
of defense experts, discovery, and full cross-examination
can address this form of error.
Bokin, Trial Court Order at 12 n.9 (specifically rejecting
Professor Koehler’s position that error rates be combined with
match probability statistics).
114
argument was rejected by the Court of Appeals twelve years ago in Porter II.
See 618 A.2d at 641 n.22 (refusing to hold that, merely because the numbers are
so high, "admission of statistics as to the minuscule probability of a random
match is unduly prejudicial"). To the extent that the PCR/STR analysis in these
cases analyzed more loci than were typically examined in the RFLP process
used in 1992, the counterbalancing probative value of the random match
probability statistics has only increased since the Porter II decision. As Judge
Richter has noted, “at its best, DNA is highly probative and accurate evidence.”
Roberts/Veney Order at 18. Thus, the defendant cannot show that the
probative value of the proffered statistics in this case will be substantially
outweighed by the danger of unfair prejudice. See Johnson v. United States,
683 A.2d 1087, 1101 (D.C. 1996) (en banc).
VII.
The fact that the defendant was first identified by a
“cold-hit” on a DNA database does not affect the
admissibility of the DNA evidence.
We demonstrated supra at 20-37 that the DNA evidence in this case was
identified and analyzed by methods that are generally, if not universally,
accepted in the relevant scientific community. We also showed that the FBI lab
estimates the rarity of the DNA evidence profile, expressed as the Random
Match Probability (RMP), based on statistical formulas that are also generally
accepted in the relevant scientific community (see supra at 67-77).
115
The defendant nonetheless contends that this court must exclude the
DNA evidence because he was first identified as a suspect by a search of a
convicted offender DNA database, rather than by non-DNA evidence, and, so
he claims, there is no generally accepted method by which to calculate the
relevant probability statistics in such a “cold-hit” case.74/ He points to the
existence of three separate approaches to presenting statistical information
about cold hits as proof of a “raging controversy” among scientists that
precludes general acceptance.
The defendant is manufacturing controversy. His argument rests on three
false premises: 1) there is only one question that statistics can answer in a coldhit case; 2) the existence of more than one approach to addressing a question
means that none is generally accepted; and 3) a debate about the relative
merits of different statistical approaches is the equivalent of a “raging
controversy” over the fundamental reliability of those approaches. When
defendant’s hyperbole is put aside, and the three statistical approaches he cites
as evidence of controversy are examined more closely, it becomes clear that 1)
there are at least two questions that statistics can answer in a cold-hit case; 2)
74/
Defendant raises this claim in a separate motion captioned
“Motion To Exclude DNA ‘Inclusion’ Evidence, Expert Testimony, And
Frequency Statistics Because There Is No General Acceptance As To
The Statistical Methods Of Interpretation Of DNA Evidence That
Derives From A ‘Cold Hit’ In A DNA Database.” Citations to that
motion will be designated “Cold-Hit Motion.”
116
there is more than one generally accepted way of answering each question,
although not all are equally favored; and 3) the issue defendant raises involves,
at most, a debate over whether, in addition to being given a statistical estimate
of the rarity of a DNA profile (Question #1), a jury also needs to be given a
statistical estimate of the chance that the same DNA profile would be found in a
database the size of the searched offender database (Question #2).
Thus, the differences of opinion that defendant relies on are nothing like
the controversy that arose in the early 1990s over whether the underlying
assumptions about population genetics were sufficiently reliable to allow any
calculation of probability statistics for a DNA match. See Conneally 9/04 Decl.
at ¶15. None of the approaches defendant cites undermines the relevance of
the estimated rarity of the DNA profile at issue (Question #1), or the previously
demonstrated general acceptance and admissibility of the RMP to answer that
question. See supra at 70-77. As for the admissibility of statistics concerning the
probability of finding a match in an offender database (Question #2), the
admissibility of numbers derived from the approaches defendant cites does not
turn on their general acceptance in the relevant scientific community under
Frye because all are accepted by scientists as valid ways to evaluate a match
from a database search. Instead, their admissibility turns on the legal relevance
of Question #2, and whether the proposed approaches to that question are
compatible with legal evidentiary rule. Those determinations rest entirely within
117
the discretion of this court, and are not dependent on the approval of
scientists.75/
75/
The defendant tries to suggest that the court is required to
apply a heightened admissibility standard to cold-hit cases “where
the science itself is the lodestar of the government’s evidence
against the defendant” (Cold Hit Motion at 3). That is not the
law. Defendant relies on a passing comment by Judge Richter during
the Roberts/Veney admissibility hearings. The Roberts and Veney
cases did not involve cold hits, so Judge Richter’s comment is
dictum at best. Moreover, the comment is directed toward cases in
which the DNA match is the only evidence, which is not true in this
case. See supra, at 3-6. Finally, the comment seems to conflate
standards of admissibility with standards for deciding whether to
allow a case to go to the jury or to grant a motion for judgment of
acquittal. No court would refuse to admit otherwise admissible
evidence, such as a fingerprint match, simply because there
appeared to be no additional corroborating evidence and the court
believed that, by itself, the fingerprint evidence was insufficient
to support a conviction. No different standard should be applied
to DNA evidence.
118
As we show, the first of the statistical approaches cited by defendant,
which was recommended by the NRC I committee in 1992, is outdated and
impractical, deprives the government of relevant evidence, and would mislead
juries as to the estimated rarity of the DNA profiles. The two remaining
approaches essentially reflect a disagreement over whether it is necessary to
answer the question “what is the likelihood of finding the DNA profile from the
evidence samples in a database of a certain size?” One school of thought,
represented by the recommendation of the 1996 NRC II committee, assumes the
legal relevance of that question and advocates providing a Database Match
Probability (DMP) number to answer it. The other school, as described in an
article by Professors Peter Donnelly and Richard Friedman, says that, although
that question might be of interest in some contexts, and the NRC II formula is an
acceptable way to answer it, that question is the wrong one to address in a
criminal case.76/ This group believes, in effect, that no other probability figure
needs to be introduced with, or instead of, the RMP. See Donnelly and
Friedman, 97 Mich. L. Rev. at 962.77/
76/
See Peter Donnelly and Richard Friedman, “DNA Database
Searches and the Legal Consumption of Scientific Evidence,” 97
Mich. L. Rev. 931 (1999), attached in Defendant’s Appendix VII, TAB
J.
Other proponents of this view include David Balding, A.P.
Dawid, Ian Evett, J. Mortera, and Bruce Weir.
77/
Donnelly and Friedman also point out that a database search
produces additional information that a fact finder might find
probative; that is, one DNA profile in a database was found to
119
match DNA from the evidence while many other profiles were found
not to match. Donnelly and Friedman, 97 Mich. L. Rev. at 962. To
illustrate, in this case, even though the Virginia database search
was conducted on only an 8-loci profile, only one match with the
DNA from the evidence samples was found and that match was with the
defendant’s DNA. That means that over 100,000 former offenders’
DNA did not match the DNA from the blood at the crime scene and,
therefore, over 100,000 people have been eliminated as the possible
source of that blood. Even defendant’s experts agree that this
information has probative value. Both Doctors Mueller and Krane
testified on this issue at a DNA admissibility hearing in State v.
Robinson, Case No. 00F06871 (Superior Court, County of Sacramento,
State of California). See excerpts of their testimony, Appendix
VII, TAB H, at pp. 1571 (Mueller).
120
The government intends to introduce only the RMP numbers that represent
the estimated frequency with which the 13-loci DNA profile found in the
evidence samples would be expected to occur in four major population groups.
See supra at 6-9.78/ We believe that the rarity of the DNA profile found in the
evidence samples is always relevant. Presentation of the RMP alone does not
risk suggesting potentially prejudicial information about the defendant’s criminal
record. In addition, presentation of the RMP is consistent with the practice of
almost every DNA forensic laboratory in the country. See Budowle Decl. at ¶12;
Sensabaugh Decl. at ¶ 21 79/
78/
The government has no intention of relying on the match
between the DNA from the evidence samples and the defendant’s 8loci DNA profile in the Virginia offender database, unless the
defendant opens the door to admission of that evidence. All of the
DNA evidence that the government will introduce in its case-inchief is based on the subsequent confirmatory re-testing and
examination by the FBI laboratory, which found a match between the
DNA from the evidence samples and defendant’s DNA at 13 loci.
79/
In support of our opposition to defendant’s cold-hit argument,
we have included in Appendix VII, the declarations of four experts:
Dr. Bruce Budowle, the Senior Scientist in the Laboratory Division
of the FBI, and one of the pioneers in the development of DNA
analysis for forensic identification purposes (TAB A); Dr. Michael
Conneally, Distinguished Professor of Medical Genetics and
Neurology
at
Indiana
University
Medical
Center,
whose
specialization is the statistical aspects of population genetics
(TAB B); Dr. James Crow, Professor Emeritus of Genetics at the
University of Wisconsin, who chaired the National Academy of
Sciences/National Research Council’s Committee on DNA Technology in
Forensic Science, which published the 1996 report “The Evaluation
of Forensic DNA Evidence” (NRC II) (TAB C); and Dr. George
Sensabaugh, Professor of Forensic Biology in the School of Public
Health at the University of California at Berkeley, who was the
121
However, if the court believes that the likelihood of finding a match to the
evidence profile in the offender database is relevant, we will not object if the
defense wants to introduce, in addition to the RMP figures, the DMP figure as
calculated by the generally accepted formula recommended by the NRC II
committee in 1996. There is no controversy in the relevant scientific community
that the use of the NRC II formula is both a correct and conservative (as well as
a defendant-favoring) way to answer that question.
The government objects to admission of statistics based on the NRC I
approach because it would unjustifiably keep from the jury the fact that the
defendant’s DNA matches the evidence profile at the 8-loci used in the Virginia
database search, in addition to matching the five remaining loci on the full 13loci matching profile.
only scientist to serve on both of the special committees on the
forensic use of DNA convened by the National Research Council of
the National Academy of Sciences (commonly known as NRC I and NRC
II) (TAB D).
Because we have also included in our appendix, in support of
other arguments, the declaration that Dr. Conneally submitted in
January 2003 in United States v. Roberts and United States v.
Veney, we will identify his declaration concerning cold-hit issues
as “Conneally 9/04 Declaration”.
122
A.
The Random Match Probability (RMP) is always relevant
and admissible to show the rarity of a DNA profile.
The RMP figure that the government intends to introduce with the DNA
evidence measures the estimated frequency, or rarity, with which a particular
DNA profile is expected to occur in a given population. The rarity of a profile is
relevant information, and can be highly probative. If the person who commits a
crime is believed to have a particular characteristic - whether it is height, eye
color, blood type, or a DNA pattern – then it is relevant that the defendant also
has that characteristic, because sharing that characteristic tends to make it
more probable that the defendant is the person who committed the crime. See
Winfield v. United States, 676 A.2d 1, 2 (D.C. 1996) (en banc) (evidence is
relevant if it tends “to make the existence or nonexistence of a fact more or less
probable than would be the case without that evidence”) (internal quotation
marks and citation omitted). If the characteristic is fairly common, then the fact
that the defendant also has that characteristic, while still probative of identity,
will nonetheless carry relatively little weight. Conversely, if the characteristic is
very rare, then the fact that the defendant has that characteristic can be highly
probative.
The relevance of the RMP as an indicator of the rarity of the DNA profile
found in an evidence sample is the same regardless of whether the suspect is
identified by non-DNA evidence or by a DNA database search. Crow Decl. at
123
¶9. In fact, the RMP can be calculated from the DNA profile in the evidence
sample before any suspect is identified. Sensabaugh Decl. at ¶ 21. Once
determined, the RMP of a DNA profile never changes, unless additional loci are
examined. Crow Decl. at ¶11; Sensabaugh Decl. at ¶ 21.80/ It is the common
practice of forensic laboratories to report the RMP regardless of whether the
defendant was first identified from a database search or from non-DNA
evidence. See Budowle Decl. at ¶12; Sensabaugh Decl. at ¶ 21.
Although not all cases involve a 13-loci match,81/ in a case like this one
where the DNA profiles from the evidence samples and from the defendant
match at 13 loci, the probative value of the match is very high. A profile
containing a particular combination of 26 alleles (13 loci X 2 alleles at each
locus) is an exceedingly rare event in statistical terms. See Crow Decl. at ¶¶ 13,
16. It is so rare that the government’s expert is prepared to opine that, to a
reasonable degree of scientific certainty, the DNA profile is unique. See supra at
8. The jury is entitled to learn of the rarity of the full evidence profile, in order to
give proper weight to the significance of a match at all 13 loci. The value of the
RMP should not be artificially diminished.
80/
For an explanation of the generally accepted formulas used to
develop the RMP in cases involving single-source DNA samples and
mixed-source DNA samples, see supra at 77-91.
81/
Sometimes there is insufficient DNA from which to obtain a 13loci profile.
124
The three statistical approaches described in defendant’s motion are not
substitutes for the RMP. Those approaches focus on an entirely different
question, and the way in which one chooses to address that question does not
affect the relevance and general acceptance of the RMP as a measure of the
rarity of a DNA profile.
The DNA Advisory Board (DAB) explained in a 2000 position paper that
there often are several statistical approaches to evaluating DNA evidence, and
all may be valid, depending on the question being asked:
When a comparison of DNA profiles derived from evidence and
reference samples fails to exclude an individual(s) as a
contributor(s) of the evidence sample, statistical assessment and/or
probabilistic reasoning are used to evaluate the significance of the
association. Proper statistical inference requires careful formulation
of the question to be answered, including, in this instance, the
requirements of the legal system. . . .
As the NRC II Report (1996) describes,82/ there are alternative
methods for assessing the probative value of DNA evidence. Rarely
is there only one statistical approach to interpret and explain the
evidence.
DNA Advisory Board, “Statistical and Population Genetics Issues Affecting the
Evaluation of the Frequency of Occurrence of DNA Profiles Calculated From
Pertinent Population Database(s)” (February 23, 2000), published in Forensic
Science Communications Vol. 2 No. 3 (July 2000) (hereafter “DAB Position
82/
See NRC II at 192.
125
Paper”) (Appendix VII, Tab E).83/ After repeating its general endorsement of the
NRC II report, the DAB explained that its position paper was written to clarify
issues that arose in special cases, including cases involving a felon database
search. DAB Position Paper at 2.
With respect to such cold-hit cases, the DAB said:
Two questions arise when a match is derived from a database
search: (1) What is the rarity of the DNA profile? and (2) What is the
probability of finding such a DNA profile in the database searched?
These two questions address different issues. That the different
questions produce different answers should be obvious.
Id. at 6.
The first question, which is relevant in all cases involving DNA evidence,
“addresses the random match probability, which is often of particular interest to
the fact finder.” Id. See Budowle Decl. at ¶11; Conneally 9/04 Decl. at ¶7; Crow
Decl. at ¶9; Sensabaugh Decl. at ¶¶ 21-22 . The second question – what is the
probability of finding such a DNA profile in the database searched? – is the
question at issue in the three approaches cited by defendant.
B.
The approaches cited by defendant are generally
accepted methods of answering questions other than
the rarity of a DNA profile, but not all are admissible
under legal evidentiary standards.
VII.
The NRC I Approach
83/
Defendant includes an incomplete excerpt from this position
paper in the Appendix to his Cold-Hit Motion. The government has
included the entire paper so that its meaning is not misunderstood.
126
The first, now discredited, approach to evaluating the relevance of a cold hit on a
database was recommended by the NRC I committee on forensic DNA evidence in 1992. It is
generally accepted in the relevant scientific community that the NRC I approach is outdated and
unnecessarily wastes probative information. For the same reasons, use of the NRC I formula is
not legally appropriate because it leads to the unjustifiable exclusion of probative information.
The NRC I report was issued more than a dozen years ago when DNA testing methods
were less reliable and less discriminating, and therefore scholars feared that they would be more
likely to lead to purely coincidental matches with innocent people. See Conneally 9/04 Decl. at
¶12; Crow Decl. at ¶12. The NRC I committee reacted by recommending an approach that keeps
from the jury not just the statistic based on the database match, but the fact of a database match
and any evidence that was used to obtain the database match.
NRC I recommended testing a limited set of DNA markers for comparison with a
database. If there was a match, then the evidence sample and the DNA of the person who
matched would be re-tested on an entirely different set of markers. Only the second set of
markers would be used to develop the random match probability number, and the jury would not
be told that the defendant’s DNA profile also matched the evidence profile at the first set of
markers. See NRC I at 124.
The NRC I approach was developed before there had been any cold hits on DNA
databases, and at a time when DNA testing was conducted by the restriction fragment length
polymorphism (RFLP) method. Sensabaugh Decl. at ¶ 17. RFLP tended to examine a much
smaller number of DNA markers than the modern system of PCR/STR analysis, and was less
precise, which meant that the possibility of a purely coincidental match was greater. The NRC I
127
committee recognized that there were alternative statistical approaches to evaluating the effect of
database searches; however, it rejected those approaches because of doubts about the ability
under then-current testing methods and sampling techniques to accurately estimate genotype
frequencies. NRC I at 124. Instead, it chose to avoid the database issue, by ignoring the markers
used in the initial database search. NRC I at 124.
A mere four years after the NRC I report was published, and before forensic laboratories
had applied the NRC I recommendation, the NRC II committee concluded that the NRC I
approach wasted information, and would create problems in cases in which there was insufficient
DNA for subsequent re-testing. NRC II at 34, 133. It recommended instead the reporting of a
database match probability (DMP) number, which is described infra at 112-116.
In addition to the deficiencies noted by the NRC II committee, the NRC I approach would
be costly and impractical. To reduce the possibility of an erroneous identification of a suspect
from a database, it would be desirable to use a significant number of validated markers in a
database search. The NRC I approach would require laboratories to develop and validate a
similarly large set of independent markers for use at trial. Maintaining the ability to test and
analyze DNA at numerous markers, and identifying and validating new markers for such testing,
would be very time-consuming and costly. See Donnelly and Friedman, 97 Mich. L. Rev. at 965
& n.85 (describing additional testing and validation costs).
Moreover, the NRC I approach is no longer appropriate. Even if, from a statistician’s
perspective, that approach may still be a technically acceptable way of addressing a database
search, it is generally agreed among knowledgeable scientists that the current ability to develop
more accurate and discriminating DNA profiles makes the NRC I recommendation outdated and
128
unnecessarily conservative. See Conneally 9/04 Decl. at ¶12; Crow Decl. at ¶15; Sensabaugh
Decl. at ¶18. Thus, like the ceiling principles that were adopted by the NRC I committee to
compensate for uncertainties about the reliability of the population genetics on which the
statistical probabilities were based, and that were later abandoned as further research and
experience erased those uncertainties, see supra at 70-77, the NRC I cold-hit case
recommendation has outlived its arguable relevance.
Defendant’s assertion that the NRC I approach “currently enjoys a number of followers”
does not withstand scrutiny. Cold-Hit Motion at 18. He cites the writings of Professors Newton
Morton, Richard Lempert, and Aidan Sudbury from seven or more years ago, before forensic
laboratories were widely using the more discriminating PCR/STR methods of developing and
analyzing DNA profiles. The fact that scientists might have agreed with the NRC I
recommendation years ago is not proof that they continue to hold those views today, particularly
in light of the shortcomings that were identified by the NRC II report, and the significant
advances in the science of DNA analysis since both NRC reports were published.
For example, Professor Richard Lempert, a member of the NRC I committee who often
serves as a criminal defense attorney, and who once agreed with the NRC I recommendation,
now rejects that approach. In Professor Lempert’s opinion, “the recommendation of NRC I is
outdated and defunct [, and] there is no need to type additional loci when a cold hit has been
made from a felon database. This is based on the fact that the current STR technology provides
sufficient power of discrimination.” Declaration of Dr. Richard Lempert [in People v. Robinson,
129
No. 00F06871, Superior Court for the County of Sacramento]; see App. VII at Tab G.84/ For
similar reasons, Dr. George Sensabaugh, the only scientist to serve on both NRC I and NRC II,
also rejects the NRC I recommendation. Sensabaugh Declaration at ¶18.
Moreover, the fact that some scientists may prefer this method does not mean that they
think that other methods are not generally accepted. For example, a scientist might well say that
testing blood samples is a more accurate and better way of assessing the degree of alcohol
intoxication of a suspect. Even if true, it would not follow that use of a Breathalyzer test would
not be generally accepted as a sufficiently reliably way to assess the same thing. In the same
vein, although Dr. Newton Morton has written in support of the NRC I approach, he also agrees
in principle with the NRC II approach; he does not endorse that approach because of concerns
that it would reveal to the jury prejudicial information about a defendant’s criminal record. See
Donnelly and Friedman, 97 Mich. L. Rev. at 963 n.81.85/
84/
It is surprising that defendant claims that Professor Lempert
still endorses the NRC I position (see Cold Hit Motion at 18). As
indicated by Professor Lempert’s declaration, he found it necessary
to correct that misrepresentation of his views in a California case
captioned People v. Robinson. Professor Lempert was responding
directly to inaccurate assertions about his position that
apparently had been made in the Robinson case by two of the
defendant’s proffered experts in this case – Dan Krane and Laurence
Mueller. Neither one repeats those inaccurate assertions here.
85/
It is worth noting that this reason for preferring NRC I has
nothing to do with the validity of the science, but relates to
legal concerns about the prejudicial effect of information on the
jury.
130
Nor is it significant that defendant’s experts – Dan Krane and Laurence Mueller – prefer
the NRC I approach.86/ Those defense experts advocated the same position in a recent California
case that dealt solely with the cold-hit issue. Their position was rejected because the trial court
concluded that they were not prominent experts in the relevant field, and their views were not
representative of such experts.
After considering the testimony of five expert witnesses, a Sacramento, California, trial
court found that it was generally accepted in the relevant scientific community to present just the
RMP as a measure of the significance of a DNA match in a cold-hit case. See Transcript of
Court’s Ruling Re: DNA Evidence, People v. Robinson, No. F06871 (Superior Court of the State
of California, County of Sacramento, Dept. 30, Feb. 20, 2003) [Honorable Peter Mering
presiding] (hereafter “Robinson Ruling”) at 21 (included in Govt App. VII, Tab F).87/ The
defendant in Robinson relied on the testimony of Drs. Krane and Mueller, who, as they have in
this case, attempted to persuade the court that there was a bitter controversy, and therefore no
consensus, about the correct way in which to present a statistic evaluating the significance of a
86/
The defendant also presents the declaration of Dr. Sandy
Zabell, but Dr. Zabell simply describes the relationship among the
three approaches described in the text. He does not suggest that
any of three approaches is wrong or not generally accepted, or that
the existence of three approaches is evidence of a lack of
consensus as to their general acceptance in the scientific
community.
87/
Although California adds requirements to the Frye test for the
admissibility of evidence derived from novel scientific methods,
the first step in its analysis is the general-acceptance standard
announced in Frye, which still applies in the District of Columbia.
See supra at 16-20.
131
match in a cold hit case. They also advocated use of the NRC I approach. The trial court
rejected their opinions, finding that:
[W]hile [Drs. Krane and Mueller] are qualified, . . . they are [not] heavy hitters
in the scholarly world. They are not persons whose articles are quoted or
considered authoritative in the field.
And it is a fact of some importance that they have consistently over the years
resisted virtually each and every development in DNA processing and DNA
science, and continue to resist many of them even though [the developments]
have, as time has passed, become accepted by the general scientific community.
So . . . either they are of the old school in some way are extremely conservative in
the way these things ought to appear, or they have discovered that their services
are in demand because they do adhere to the old system and reject the new. So I
don’t feel their position is one of substantial scholarly importance.
Robinson Ruling at 14.88/
88/
The California court’s conclusion was amply supported by the
record. For example, Dr. Mueller admitted that he does not attend
professional conferences at which current developments in DNA
analysis and interpretation are presented and discussed, does not
publish on forensic DNA subjects, and has testified for the
government only once in all of the 125-160 cases in which he has
previously testified (see App. VII, TAB H a pp. 1527, 1537-38).
Similarly, Dr. Krane does not attend relevant professional
conferences, is not a participant in working groups on DNA analytic
methods, has never published on the cold hit issue, and testifies
almost exclusively for defendants (App. VII, TAB H, at 1770-73,
1777-78).
He advocates positions, such as use of the ceiling
principle, that he acknowledges are not generally accepted in the
relevant scientific community. App. VII, TAB H at 1794-1795. In
another example, although Dr. Krane agrees that the rarity of the
tested DNA profile is relevant, and that the NRC I formula does not
give the “closest true frequency” of such a profile, he still
endorses the NRC I approach. Id. at 1873-1874. Dr. Krane candidly
admitted his bias toward proposals that favored the defendant in
the Robinson case, agreeing that it was his “inclination in every
criminal case, . . . that we should provide conservative statistics
that benefit the defendant.” App. VII, TAB H at 1795.
132
Finally, even if there were some scientists who still preferred the NRC I approach, that is
not a reason to choose that approach over other approaches that reflect more up-to-date science,
and do not result in the exclusion of probative evidence. As the Court of Appeals emphasized in
Porter II, “[I]f the evidence offered conduces in any reasonable degree to establish the probability
or improbability of the fact in controversy, it should go to the jury.” United States v. Porter, 618
A.2d 629, 640 (D.C. 1992). Thus, the NRC I approach unjustifiably would hide from the jurors
in this case the fact that the defendant’s DNA profile matched the DNA from the evidence
samples at the eight markers initially used to make the database match. It would also prevent the
jurors from learning of the RMP based on the entire 13-loci profile, and leave them with an
artificially reduced RMP that would give them the false impression that the DNA profile is more
common than it probably is.
Applying the NRC I approach to non-DNA evidence illustrates the absurdity of its result in
a criminal case. Suppose that a woman is robbed by a person whom she is able to describe to the
police in detail as: 1) male; 2) fair complected; 3) bald, but with 4) grey hair around the sides; 5)
blue-eyed; 6) with a moustache; 7) with ears that stick out; and 8) over 40 years old. The victim
also tells the police that the robber 9) held his gun in his left hand; 10) had a deep voice; 11) was
bow-legged; 12) stood about 5'11" tall; and 13) weighed about 300 lbs. After trawling through a
book of mug shots, the victim selects a photograph of a man who looks like the robber based on
the first eight characteristics that she described. To confirm that identification, the police have her
look at a line-up which includes that man. The line-up is arranged so that the victim can only see
the individuals in silhouette; that is, she is deliberately prevented from seeing any of the
133
characteristics by which she selected the photograph. The silhouettes reveal height and weight,
and, through demonstrations, the witness is able to observe whether the individuals in the line-up
are bow-legged, are left-handed, or have deep voices. Based on those five characteristics, the
victim selects the same man that she identified from the photographs. At trial, the government is
allowed to present evidence about the line-up identification, but it is precluded from mentioning
the photo identification or that the victim initially described 13 rather than five characteristics of
the robber, and the victim is permitted to testify only that the robber was 5'11" tall, about 300 lbs,
bow-legged, and left-handed, and had a deep voice. Obviously such a distorted procedure could
not be justified with respect to non-DNA evidence. Nor can it be justified for DNA evidence on
the basis of an outdated recommendation.
Defendant’s suggestion that the NRC I approach is justified because there is an increased
danger that an innocent person will be identified in a database search is misguided. The
discriminating power of a DNA profile increases as the number of markers included in the profile
increases. There is a greater likelihood of finding several persons whose DNA profiles match if
only four or five markers are compared (as was typically the case when the NRC I and NRC II
reports were issued). Sensabaugh Decl. at ¶ 17. That possibility decreases as additional markers
are compared until the likelihood of a coincidental match is infinitesimally small.89/ The DNA
89/
Thus it is not surprising to learn of a 9-loci match, and
certainly not surprising to learn of several 6-loci matches,
particularly where most of the 6-loci matches were among brothers.
Siblings are more likely to share similar DNA profiles, but even
they are not likely to be found to match at a higher number of
loci. Nothing suggests that relatives of the defendant should be
suspected of the murder in this case.
134
profiles developed from the numerous evidence samples in this case were, with few exceptions,
13-loci samples. See supra at 6-9. To date, genetic researchers have never seen a false
coincidental match between 13-loci profiles. Crow Decl. at ¶13.
Defendant correctly notes that the NRC I approach “could dramatically reduce the
government’s random match probability calculations by a number of magnitudes.” Cold-Hit
Motion at 17. This, in turn, would give the jury the false impression that a given DNA profile was
“dramatically” more common than it likely would be if all the matching markers were used to
calculate the RMP. There is no scientific imperative that requires the court to admit an artificially
deflated RMP, or keep from the jury the fact that the defendant’s DNA matched the DNA from
the evidence at the eight loci used in the database search.
The NRC I approach unjustifiably deprives the jury of otherwise probative and relevant
evidence. Even if the NRC I approach was not practically obsolete, statistics derived from the
NRC I approach should not be admitted.
2.
The NRC II Approach
A second approach was recommended by the NRC II committee in 1996. That committee
noted that NRC I’s approach wasted information unnecessarily and assumed that DNA samples
could be retested, which was not always the case. NRC II at 124. In its Recommendation 5.1,
NRC II recommended a method that uses information about all of the tested markers to develop
the RMP, then multiplies that RMP by the number of profiles searched in the database, or “N”.
The result is a number that represents the chance of finding a match – whether true or coincidental
– in a database of a certain size. That number is sometimes called the Database Match Probability
(DMP).
135
Knowledge of the DMP does not help the fact finder decide whether the match is true or
coincidental. However, if you assume that the true source of the DNA evidence sample is not in
the database, then the DMP can answer the question “what is the chance that the match between
the DNA evidence profile and the profile found in the database is coincidental?” Expressed that
way, the DMP might be information that the defense would want to introduce to a jury. The DMP
does not measure the rarity of a profile, however, and thus it is not a substitute for the RMP in
answering that question. The rarity of a profile is typically the more relevant question. For that
reason, forensic laboratories always report an RMP number in cold hit cases, and provide a DMP
number if it is requested by one of the parties. See Budowle Decl. at ¶12.90/
Although some commentators have treated the NRC II recommendation as though it
precludes giving the RMP, the NRC II committee did not say that, if the DMP was given, the
RMP should not also be used to express the rarity of the DNA profile. Even if the language of
Recommendation 5.1 is ambiguous in some respects, the subsequent DAB position paper clarifies
that the NRC II formula answers only one of two questions that arise in a cold-hit case. The
RMP answers the other.91/
90/
Defendant is misinformed when he insists that “no scientist
agrees with the government’s proposal to simply place before the
jury the random match probability [in a cold hit case] as one does
in more traditional DNA ‘confirmation’ cases.” Cold Hit Motion at
11.
Forensic scientists throughout the country do just that.
Moreover, that is essentially the effect of following the third
approach cited by defendant. See infra at 116-118.
91/
Defendant mischaracterizes by omission one of the important
points made in the DAB position paper, which is that there are two
relevant questions in a cold hit case.
Although the paper
expressly concerned itself with two of the alternative proposals
for addressing the likelihood of finding a DNA profile in a
136
database of a particular size, that does not mean that the DAB
thought that the rarity of a profile was unimportant.
To the
contrary, the DAB described that question as “often of particular
interest to the fact finder.” DAB Position Paper at 8.
137
Dr. George Sensabaugh, who is the only individual to have served on both NRC I and
NRC II, explains that, based on the language of the report and presentations and discussions at
NRC II meetings, it was not his understanding that the NRC II recommendation to report a DMP
was intended to preclude introduction of the RMP to express rarity of the profile. Sensabaugh
Decl. at ¶22. Nor was that the understanding of Dr. James Crow, a prominent population
geneticist who chaired the NRC II committee. Crow Decl. at ¶11.
That is the only logical way to read the NRC II report as a whole because, as even
defendant’s experts agree, the DMP and RMP measure different things, see App. VII, TAB H,
pp. 1568 (Mueller), and only the RMP measures rarity. See Conneally 9/04 Decl. at ¶7. In
addition, the fact that a suspect has been identified through a database search does not mean that
the DNA profile of interest has become more commonplace. All that a database search does is
make it more likely that you will find the profile that you are looking for, but that would be true
regardless of whether the profile was common or rare.
Moreover, providing just the DMP number to a jury would be misleading. For example, if
the RMP for an evidence profile was 1 in 1,000,000, that tells the jury that the estimated
frequency with which the profile would be expected to occur in a particular population is one
person in a million. See Budowle Decl. at ¶15. Suppose we then searched for that profile in a
database of 1 Million people. The DMP would be calculated by multiplying the RMP of
1/1,000,000 by the size of the database (1,000,000). The resulting DMP would be 1, which
suggests that you would expect to find that DNA profile in that database one hundred percent of
the time. If that were the only figure given to the jury, it could easily be misinterpreted as
meaning that everyone in the population has that DNA profile, or at least that the profile was
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extremely common, when in fact, at least 999,999 people were actually found not to have that
profile. Budowle Decl. at ¶15. Such a distortion of the evidence is unwarranted, and can be
avoided by ensuring that, in any case in which the DMP is introduced, the RMP is also provided
as a separate measure of the rarity of the profile.
That is essentially what would occur in a cold hit case if the position of the DNA Advisory
Board was followed. In its 2000 position paper, the DAB examined the arguments for and against
presenting a statistic that expresses the chance of finding the DNA profile of interest in an
offender database. It chose to endorse the NRC II recommendation that a DMP number be given,
primarily because that was a conservative approach. DAB Position Paper at 8; see also Budowle
Decl. at ¶18.92/ At the same time, the DAB would not oppose giving the RMP as well, because
the DMP measures only the probability of finding a profile in the database, and does not
supersede the need to introduce the RMP as a measure of the profile’s rarity. See Budowle Decl.
at ¶10.93/
92/
Dr. Budowle was one of the authors of the DAB Position Paper.
Budowle Decl. at ¶10.
93/
The
DAB
specifically
considered
whether
the
NRC
II
recommendation or the third approach cited by the defendant (the
Donnelly and Friedman approach) was preferable in a cold hit case.
The Board ultimately chose to endorse the NRC II approach because
it was more conservative. In its position paper, the DAB points
out that the reasoning of the Donnelly & Friedman approach depends
heavily on an understanding of the use of likelihood ratios and
Bayesian logic, concepts that are difficult for laymen to
understand and apply in a criminal setting. Thus, the DAB position
paper concludes that, even though the NRC II approach and the
Donnelly/Friedman approach both “yield a coherent evaluation of
the evidence” in the context of likelihood ratios, the Board
prefers the NRC II approach because it “communicates value of a
database search far better, and it is always conservative.” DAB
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3.
The Donnelly and Friedman Approach
Adherents to the third approach identified by the defendant agree with the NRC II
committee that the NRC I recommendation is unnecessarily wasteful and impractical. See, e.g.,
Donnelly & Friedman, 97 Mich. L. Rev. at 963-966. However, they also argue that it is
unnecessary to treat a cold hit case differently from a case in which the defendant is first identified
by non-DNA evidence.
Position Paper at 8; see also Budowle Decl. at ¶18.
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The third approach (hereafter “the Donnelly & Friedman approach”) reflects the intuitively
logical idea that “the value of a DNA match is attributable to the rarity of the profile.” Donnelly
and Friedman, 97 Mich. L. Rev. at 944.94/ The question of interest to the jury is how probable is it
that the defendant whose profile matched the evidence sample profile is in fact the source of that
sample, and that question can be answered in a simple way by the RMP. Id. at 947.95/ It is
undisputed that the fact that the defendant is first identified through a database search does not
change the rarity of the DNA profile at issue, as expressed by the RMP. Thus it does not change
the RMP’s value in proving that the defendant is the source of the DNA found in the evidence.
Donnelly & Friedman also point out that, if anything, the fact that the defendant’s profile was the
only profile found to match the evidence while many other profiles were found not to match
makes the evidence overall slightly more probative than the RMP alone. Id. at 948.96/
94/
Other notable scientists who generally agree with the position
described by Donnelly and Friedman include David Balding, A.P.
Dawid, Ian Evett, J. Mortera, and Bruce Weir. Conneally 9/04 Decl.
at ¶14.
95/
Although the proponents of the Donnelly & Friedman approach
typically rely on more complex ways of presenting statistical
information than simply statements of the RMP (such as likelihood
ratios and Bayesian logic), the logic of their reasoning is that
the RMP expresses the information that the jury needs to hear. See
Donnelly & Friedman, 97 Mich. L. Rev.
96/
Contrary to the defendant’s repeated assertions, Donnelly &
Friedman do not contend that, under their approach, the overall
value of the DNA evidence is significantly greater in a cold hit
case than in other cases. Therefore, their approach is far more
moderate, and the differences with the NRC II approach are far
less, than the defendant would have this court believe.
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To the extent that people interpret NRC II as dictating only the DMP, Donnelly and
Friedman also underscore the anomaly of the NRC II approach as the size of the searched database
approaches the size of the entire population in question. Basically, under the NRC II formula, the
probative value of the DNA match appears to decrease as the size of the database, or the number
of profiles actually searched, increases. Eventually, if all profiles in the population are searched,
and only one profile matches the evidence profile, then the logic of the NRC II formula leads to
the conclusion that the unique match has no probative value. Of course, if everyone else in the
population has been eliminated as a source of the evidence profile, then the match should instead
be conclusive proof of identity. See Donnelly and Friedman, 97 Mich. L. Rev. at 952-954. The
NRC II report recognizes this anomalous result, but offers no solution. See NRC II at 161.
The Donnelly and Friedman article presents cogent criticisms of the NRC II’s view that a
database match probability number must be presented to a jury, but this does not create a
controversy under Frye. Donnelly and Friedman emphasize that they are not saying that the NRC
II recommendation is based on unacceptable science. Rather, they contend that NRC II answers
an unnecessary question in a forensic setting. The question tested by the NRC II approach is
whether the source of the crime sample is in the database, a question that may intrigue
academicians, but is of little or no interest to a jury. Id. at 946. At bottom, Donnelly & Friedman
are arguing legal relevance, not scientific reliability.
At least one trial court to have addressed the various statistical approaches in a cold hit
case has found, under a Frye-Plus test, that the Donnelly and Friedman approach is generally
142
accepted in the relevant scientific community. See Robinson Opinion, App. VII, TAB F.97/ The
result is that the government will be allowed to introduce the RMP. Id. At the same time, that
court also held that the defendant would be permitted to introduce the DMP figure, as calculated
by the NRC II formula, if he chose to do so. Id. Because whether the DMP should be introduced
in addition to the RMP is a matter of legal relevance rather than scientific acceptance, that
decision is an acceptable compromise between the NRC II approach and the Donnelly and
Friedman approach.
Therefore, as previously noted, if this court believes that a measure of the chance of
finding the evidence profile in a database is relevant, and the RMP is admitted as a measure of the
rarity of the DNA profile, then the government has no objection to the defendant introducing the
DMP as calculated by the generally accepted and conservative NRC II formula.98/ Where the
RMP is also given, the DMP cannot be misinterpreted, and the introduction of both would be a
scientifically and legally acceptable, albeit conservative, approach to explaining the significance
of a database match. Where there is a choice between two differing approaches, but agreement
that one is acceptably conservative, then the court does not err by following the more conservative
path. Cf. Porter, 618 A.2d at 640-642.
97/
Applying a Frye-Plus test, a Minnesota trial court has also
recently rejected, without a hearing, the argument that a different
statistical rule than the RMP should be applied when a suspect is
identified from a database search. See State v. Johnson, Court
File No. 02096915, and State v. Grant, Court File No. 04031951,
District Court, Hennepin County (August 16, 2004) [Honorable Steven
A. Pihlaja]; attached at Appendix VII, Tab I.
98/
This could be done through cross-examination of
government’s expert or through a separate defense expert.
143
the
Of course, if the DMP figure is admitted in addition to the RMP, the court should bear in
mind the likely need to sanitize references to the database (as is often done, for example, when
arrest photos are introduced as part of a photo array); and the fact that introduction of the database
figure will open the door to appropriately sanitized cross-examination (or redirect) about how the
DMP was calculated, and how many individuals were actually excluded as sources of the DNA
from the crime scene evidence as a result of the database search.
C.
The failure to incorporate estimates of error rates into the
probability statistics does not preclude admission of the
DNA evidence in a cold hit case.
As he did in his Supplemental Motion with respect to all probability figures, defendant
contends that the probability figures used in a cold-hit case must incorporate estimates of laboratory
error, or “false positive,” rates before the probability statistics are admissible (Cold Hit Motion at 2426). We have previously demonstrated that this issue is not properly before the court because,
ordinarily, the question of error goes to the weight of the evidence and not its admissibility. See supra
at 91-94. In addition, such an approach is generally rejected by scientists. Id. For the same reasons,
defendant’s argument does not preclude the admissibility of the DNA evidence.99/
99/
Ironically, defendant cites in support of his error-rate
argument Professor David Balding’s 1997 article, which was written
in reaction to the NRC II report (Cold Hit Motion at 24). In that
article, Professor Balding agrees with the government’s position
that it is inappropriate to combine error rates with match
probabilities. See Balding, “Errors and Misunderstandings in the
Second NRC Report,” 37 Jurimetrics J. 469, 476 (1997) (attached in
defendant’s Cold Hit Appendix).
He also concludes that “what
matters are not the probabilities of any profiling or handling
errors, but only the probabilities of errors that could have led to
the observed DNA profile match.” Id. at 475-476.
144
In addition, defendant misses the mark when he suggests that the court should be concerned
about the possible error rate at the labs that administer the Virginia database program (Cold Hit
Motion at 26). The evidence that the government intends to introduce is derived solely from the
confirmatory testing by the FBI lab, which involved re-testing DNA from a new sample of
defendant’s blood. The practices of the Virginia lab are irrelevant.
D.
The probative value of the DNA evidence in a cold-hit
case is not outweighed by prejudicial effect.
Similarly, defendant repeats the argument that the probative value of the DNA evidence is
outweighed by its prejudicial effect, but his arguments are unpersuasive (see Cold Hit Motion at 2628). As we noted earlier in our opposition, the Court of Appeals in Porter rejected the argument that
jurors will be so overwhelmed by statistics suggesting “a minuscule probability of a random match”
that they cannot be trusted to consider the evidence. Porter II, 618 A.2d at 641 n.22. Except for
adding arguments about how error rates should reduce the probative value of random match numbers,
defendant’s Cold Hit Motion adds nothing else new to his argument about prejudice. That argument
should be rejected for the reasons we have stated before. See supra at 90-94.
Defendant also overstates the conclusions of an article by Professor Jonathan Koehler, by
suggesting that it supports the idea that “the power of the DNA evidence to mislead and confuse the
jury is great” (Cold Hit Motion at 27). The primary thrust of the article is how jurors’ perceptions of
DNA evidence can be changed by the way in which the prosecutor and defense attorney describe it,
which, to a trial attorney, makes the DNA evidence no different from other kinds of evidence.
145
E.
The chain of custody for defendant’s DNA sample in the
Virginia offender database is irrelevant to this case.
Defendant’s final complaint is that the United States cannot prove the chain of custody for the
sample of biological evidence from defendant that was entered into the Virginia offender database
(Cold Hit Motion at 28-29). The chain of custody in Virginia is irrelevant because, after the cold hit
on the Virginia database, the United States obtained a new sample from appellant and the FBI
performed a confirmatory test on that new sample. The defendant does not challenge the chain of
custody for that confirmatory sample.
Even if defendant had challenged the chain of custody for the relevant DNA samples, there is
no need to consider chain of custody issues before trial. The cases defendant cites stand for the
unremarkable proposition that, where the government intends to rely on real evidence that is fungible,
it must be able to establish, through a chain of custody, that the evidence offered at trial is connected
to the defendant. E.g., Turney v. United States, 626 A.2d 872, 843 (D.C. 1993) (government required
to prove that material recovered from defendant was same material analyzed by chemist and found to
be illegal drug); Novak v. District of Columbia, 82 U.S. App. D.C. 95, 95-96, 160 F.2d 588, 588-89
(D.C. Cir. 1947) (same regarding urine sample and urinalysis test results); Smith v. Deppish, 807 P.2d
144, 238 (Kan. 1991) (noting, in dictum, that DNA test results that are otherwise generally accepted
in scientific community may still be challenged on evidentiary grounds, such as those involving
chain-of-custody); State v. Scott, 33 S.W.3d 746, 760 (Tenn. 2000) (“witness must be able to identify
the evidence or establish an unbroken chain of custody”; also noting that chain of custody was
146
“especially important” in cases, like Scott’s, involving mitochondrial DNA (“mtDNA”) because
mtDNA is “hypersensitive” to contamination).100/
Ordinarily, “evidence of a break in the chain of custody only affects the weight to be given to
the evidence.” In re D.S., 747 A.2d 1182, 1187 (D.C. 2000). “[W]hen physical evidence is in the
hands of government, the presumption arises that it has been handled properly.” Id. Moreover, the
government does not have to prove such a chain beyond any doubt; “once the government has
established an ‘unbroken chain of custody as a matter of reasonable probability,’ defendant must
present evidence of tampering” before the challenged evidence may be excluded. Id. (internal citation
omitted).
In this case, the chain of custody will be established as it normally would be – through witness
testimony at trial. MPD officers will testify about how they obtained and handled the evidence until
they delivered it to the FBI for analysis. FBI witnesses will testify about the procedures they followed
to ensure the chain of custody. The defendant will be able at that time to pursue any weaknesses in
the chain of custody. Until then, the chain of custody issue is not properly before the court.
VIII.
The Court does not need to hold an evidentiary
hearing on all of the defendant’s claims.
The Court does not need to hold an evidentiary hearing to rule on the admissibility of the DNA
evidence in this case, because it may base its decision on the findings of other courts and other
reliable record material such as scientific literature. See, e.g., Karamychev, 772 A.2d at 812 n.8;
Porter II, 618 A.2d at 635; Jones, 548 A.2d at 41. See also, e.g., People v. Brown, 40 Cal. 3d 512,
530 (1985) (endorsing practice of looking to other states' precedents in determining whether technique
100/
This case does not involve mitochondrial DNA.
147
is generally accepted), rev'd on other grounds, 479 U.S. 538 (1989); Hadden v. State, 690 So. 2d 573,
578 (Fla. 1997) (same); Owens, 725 N.Y.S. 2d at 182 ("Novel scientific evidence may be admitted
without any hearing at all by the trial court.").
"Widespread appellate endorsement of a scientific technique should ordinarily end the need
for case-by-case adjudication in the trial courts." Grant, 32 Conn. L. Rptr 30, 2002 WL 853627, at *6.
As the Connecticut trial court explained,
Scientific research is a national – or global – phenomenon, and there is no need for a
court in one state to disregard the judicial decisions of other jurisdictions. . . . While a
single appellate decision in one state does not automatically settle the issue, at some
point the combined weight of judicial and scientific opinion achieves the critical mass
of persuasive authority. With respect to STR evidence – at least in the absence of
evidence reflecting a change in scientific consensus – that point has now been reached.
There is overwhelming evidence that the STR technique has gained general
acceptance. This conclusion should end the court's inquiry, and the conclusions
derived from that methodology should be held admissible.
Id. (internal citations omitted).
As we have demonstrated, there is no need for the Court to receive testimony on the general
acceptance of the PCR/STR method of DNA typing, or on use of the product rule to calculate random
match probabilities. Instead, the Court may properly conclude that those methods are generally
accepted based on the overwhelming legal and scientific consensus concerning their admissibility.
Similarly, although the Court should hold that the Frye inquiry does not extend to the particular kits
used to perform the PCR/STR analysis, we encourage the Court to make a fuller record by ruling, in
the alternative, that the Profiler Plus/Cofiler/310 Analyzer system is also generally accepted, as
demonstrated by the cases and scientific authorities cited. “The government has amply demonstrated
by a preponderance of the evidence that the proffered DNA evidence is generally accepted in the
relevant scientific community and is therefore admissible under Frye. None of the issues raised or
148
evidence presented by the defense generated sufficient controversy to preclude the admission of
DNA.” Roberts /Veney Order at 9.
Further, nothing presented by the defendant has demonstrated that the probability formulas
endorsed by the NRC are no longer generally accepted in the relevant scientific community, or that
those formulas should not have been used in this case. The Court should therefore admit the evidence
and the accompanying probability statistics.
We note that all of the above issues have been ruled upon by three judges of this court within
the past three years. The only issue that has not yet been addressed in this jurisdiction is the cold-hit
issue, but as we have indicated there is no scientific issue to be resolved. However, should the court
desire additional information regarding that issue, with sufficient notice to present the necessary
experts, the United States will be prepared to address that issue at pre-trial hearings.
In conclusion, there is ample scientific support for the admission of DNA evidence in this
case. It is therefore appropriate to submit the evidence to the jury for its consideration, subject to the
defendant’s ability to test the reliability of the evidence through the traditional means of crossexamination and through his own witnesses.
149
CONCLUSION
WHEREFORE, defendant’s motions in limine to exclude DNA evidence should be DENIED.
Respectfully submitted,
KENNETH L. WAINSTEIN,
United States Attorney.
VALINDA JONES, D.C. Bar No. 398464,
Assistant United States Attorney
MICHAEL AMBROSINO
Assistant United States Attorneys
555 Fourth Street, N.W.
Washington, D.C. 20001
150
CERTIFICATE OF SERVICE
I HEREBY CERTIFY that a copy of the foregoing Government’s Superseding Opposition to
Defendant’s Motions in limine to Preclude Introduction of DNA Evidence, was served by hand upon
counsel for the defendant, Edward Ungvarsky, PDS, 633 Indiana Avenue, N.W., 2nd Fl., Washington,
DC 20004, on this 10th day of February, 2016.
Michael Ambrosino
Assistant United States Attorney
151