ATTACKING SCIENTIFIC EVIDENCE
Professor Edward Imwinkelried
School of Law
University of California, Davis
400 Mrak Hall Drive
Davis, California 95616
(530) 752-0727
(530) 752-4704 (F)
ejimwinkelried@ucdavis.edu
I.
THE NEED TO MASTER THE TECHNIQUES FOR ATTACKING SCIENTIFIC
EVIDENCE
A.
The Incidence of Expert Testimony at Trial
Samuel R. Gross, Expert Evidence, 1991 Wisconsin Law Review 1114
B.
The Margin of Error in Expert Testimony
Paul C. Giannelli, The Admissibility of Laboratory Reports in Criminal Trials:
The Reliability of Scientific Proof, 49 Ohio State Law Journal 671 (1988)(the
results of the Laboratory Proficiency Testing Program)
The National Research Council, Strengthening Forensic Science in the United
States: A Path Forward (2009)
Commonwealth v. Melendez-Diaz, 557 U.S. 305 (2009)(Scalia, J.)(“[s]erious
deficiencies have been found in the forensic evidence used in criminal trials”)
II.
THE LARGE NUMBER OF POTENTIAL ATTACKS ON THE ADMISSIBILITY AND
WEIGHT OF EXPERT TESTIMONY
Edward J. Imwinkelried, The Methods of Attacking Scientific Evidence (5th ed. 2014)
(hereinafter cited as METHODS)
III.
THE BASIC TARGETS
A.
The Syllogistic Structure of the Typical Expert’s Direct Testimony
Edward J. Imwinkelried, The “Bases” of Expert Testimony: The Syllogistic
Structure of Scientific Testimony, 67 North Carolina Law Review 1 (1988)
B.
The Potential Targets
The Witness’s Alleged Expertise
The Witness’s Credibility
The Validity of the General Theory or Technique the Expert Is Relying On
The Reliability of the Case-Specific Information that the Expert Is Applying the
Theory or Technique to
The Manner in Which the Expert Applied the Theory or Technique to the CaseSpecific Data
The Expert’s Final Opinion
______________________________________________________________________________
IV.
TARGET #1: THE WITNESS’S ALLEGED EXPERTISE
A.
An Admissibility Attack
METHODS § 4-3
Michael Risinger, Defining the “Task at Hand”: Non-Science After Kumho Tire
Co. v. Carmichael, 57 Washington and Lee Law Review 767 (2000)
Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993)
General Electric Co. v. Joiner, 522 U.S. 136 (1997)
Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137 (1999)
Edward Imwinkelried, Expert Witness: An Unheralded Change, National Law
Journal, Feb. 5, 2001, at A10
Alexander v. Smith & Nephew, 90 F.Supp.2d 1225 (N.D.Okla.)(holding
unqualified a witness who was not board certified in the relevant
specialty), amended, 98 F.Supp.2d 1276 (N.D.Okla. 2000)
Berry v. Crown Equipement Corp., 108 F.Supp.2d 743 (E.D.Mich. 2000)
(the trial judge is to examine “not the qualifications of the witness in the
abstract, but whether those qualifications provide a foundation for the
witness to answer a specific question”)
Broders v. Heise, 924 S.W.2d 148, 151 (Tex. 1996)(“Dr. Condos’ medical
expertise is undoubtedly greater than that of the general population, but
the Heises do not establish that his expertise on the issue of cause-in-fact
met the requisites of Rule 702 . . . . Just as a lawyer is not by general
education and experience qualified to give an expert opinion on every
subject of the law, so too a scientist or medical doctor is not presumed to
have expert knowledge about every conceivable scientific principle or
disease”)
B.
A Weight Attack
METHODS § 9-15
Robert Habush, Cross-Examination of Non-Medical Experts 4-25-27
(1981)(the witness is a “Jack of All Trades”)
Tokio Marine & Fire Ins. Co., Ltd. v. Grove Mfg. Co., 958 F.2d 1169,
1174 (1st Cir. 1992)(the witness was “a professed expert in an
extraordinary array of dissimilar fields . . . .”), approvingly cited by
Margaret Berger, Evidentiary Framework, in Reference Manual on
Scientific Evidence 37, 62-63 (1994)(discussing the “professional”
witness)
______________________________________________________________________________
V.
TARGET #2: THE WITNESS’S CREDIBILITY
A.
An Admissibility Attack
People v. Kelly, 17 Cal.3d 24, 549 P.2d 1240, 130 Cal.Rptr. 144 (1976)(the
witness’s bias)
Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993)(Rule 104(a)
governs the judge’s ruling)
Edward J. Imwinkelried, Determining Preliminary Facts Under Federal
Rule 104, in 45 Model Trials 1, at §§ 62-64 (1992)
Edward J. Imwinkelried, Trial Judges–Gatekeepers or Usurpers? Can the
Trial Judge Critically Assess the Admissibility of Expert Testimony
Without Invading the Jury’s Province to Evaluate the Credibility and
Weight of the Testimony?, 84 Marquette Law Review 1 (2000)
B.
A Weight Attack
METHODS § 9-7 (bias)
1.
The first phase of the cross-examination
Pretrial indicia of bias
Ex parte testing
Non-cooperation
Trial indicia of bias
Non-responsiveness
2. The second phase of the cross-examination
The sources or causes of the bias
Prior knowledge
Cognitive bias–exposure to prejudicial, “domain irrelevant”
information” (Expert Working Group, National Institute of
Standards and Technology, Latent Print Examination and
Human Factors: Improving the Practice Through a Systems
Approach (2012))
Financial interest
The fee in the instant case
The terms of the letter of engagement
A past pattern of compensation (Michael Graham,
Impeaching for Professional Witness by a Showing of
Financial Interest, 53 Indiana Law Journal 35 (1977)
Doctrinal bias
Evelle Younger, Diminished Capacity: A Principle in
Search of Refinement, in The Prosecutor’s Deskbook 584,
586 (1971)(discussing the cross-examination of the defense
psychiatrist in the prosecution of Sirhan Sirhan, the
assassin of Senator Robert Kennedy)
____________________________________________________________________________
VI.
TARGET #3: THE WITNESS’S MAJOR PREMISE: VALIDITY OF THE GENERAL
THEORY OR TECHNIQUE THAT THE EXPERT PROPOSES USING TO EVALUATE THE
CASE-SPECIFIC DATA
A.
An Admissibility Attack
1.
Focus on the theory or technique, not the question of the global validity of
the discipline.
Risinger, supra
United States v. Fujii, 152 F.Supp.2d 939 (N.D.Ill. 2000)
1 McCormick, Evidence § 13, at 102 (7th ed. 2013)(“It is certainly
unacceptable for the expert to reply on a proposition that is literally
ineffable. An ineffable notion might be acceptable mysticisim at a
meeting of the Jedi Council, but it does not qualify as acceptable
expertise. It is also clear that it is not enough for the expert to
assert in conclusory fashion that she is her general ‘expertise,’
‘knowledge,’ or ‘education.’ Those considerations can qualify the
witness as an expert, but they” are not substitute for the required
identification of theory or technique; “To provide a useful expert
insight, the witness must identify a more specific technique or
theory. Orherwise, the witness is venturing nothing more than a
guess”)
2.
Challenge the proponent to make an empirical showing that by applying
the theory or technique, the expert can accurately draw the specific inference he or she proposes
testifying to.
Dissect any empirical studies the expert cites. METHODS § 44[c][ii]
–What was the size of the study? Does the so-called study
consist of only anecdotal evidence, an isolated instance or
two?
–What was the composition of the study? Was the database
representative? Does it include at least a significant number
of representatives of the type of person or object involved
in the instant case?
–Did the test conditions in the study approximate the
conditions in the instant case? Were the conditions too
dissimilar?
–What specific findings did the research yield? What were
the false positive rate (Type I error) and false negative
(Type II error) rates? Do not accept the expert’s assertion
that the study “demonstrated,” “established,” “indicated,”
“proved,” or “showed” that the theory or technique is valid.
General Electric Co. v. Joiner, supra
The expert relies on animal studies. However, there were
numerous differences between the parameters of the studies
and the pending case:
–The decedent was a human being while the subjects in the
study were mice.
–The decedent was an adult while the subjects were infants.
–The decedent had dermal exposure while the subjects
were directly injected.
–Relatively, the subjects received a much larger dosage
than the decedent was exposed to.
–The decedent and subjects developed different types of
cancers.
Although the plaintiff argues that it is permissible to rely on
animal studies, the Court responded that that was not the
question. Rather, the issue was whether the specific studies
cited supported the particular conclusion that the experts
proposed testifying to. After listing all the differences
between the studies and the facts of the pending case, the
Court emphasized that the trial judge may excluded expert
testimony when the judge finds that the expert has engaged
in unwarranted extrapolation. 522 U.S. at 146. In Chief
Justice Rehnquist’s words, the judge may test the
connection between “the [empirical] data” cited by the
expert and exclude the opinion when “there is simply too
great an analytical gap” between the data and the opinion.
B. A Weight Attack
“The Path Not Taken” (the expert’s failure to use a better technique)
METHODS § 10-8
Drug testing
Gas chromatogaphy/mass spectrometry
National Treasury Employees Union v. Von Raab, 489
U.S. 656, 673 n. 2 (1989)
Different modes of GC/MS: full scan, selective ion reliance, and
selective ion monitoring
2 Paul Giannelli, Edward Imwinkelried, Andrea Roth &
Jane Campbell Moriarty, Scientific Evidence § 23.03[c], at
685-86 (5th ed. 2012)
Microscopy
Giannelli et al., supra, at § 25.02[a]
Conventional optical (2,000X)
Scanning electron microscopy (200,000X)
_____________________________________________________________________________
VII. TARGET #4: THE WITNESS’S MINOR PREMISE: THE RELIABILITY OF THE
CASE-SPECIFIC INFORMATION THAT THE EXPERT WILL APPLY THE THEORY OR
TECHNIQUE TO
A.
An Admissibility Attack
METHODS § 6-10[c]
1.
The meaning of “reasonably” in Federal Rule of Evidence 703
Edward Imwinkelried, Developing a Coherent Theory of the Structure of
Federal Rule of Evidence 703, 47 Mercer Law Review 447 (1996)
In re Japanese Elec. Prods. Antitrust Litig., 723 F.2d 238, 275-79
(1983), cert. granted in part, 471 U.S. 1002 (1985)
In re Paoli RR Yard PCB Litig., 35 F.3d 717, 732-33 (3d Cir.
1994), cert.denied sub nom. GE v. Ingram, 513 U.S. 1190 (1995)
Federal Rules of Evidence 406 and 803(17)
2.
The impact of Williams v. Illinois, 132 S.Ct. 2221, 183 L.Ed.2d 89 (2012)
The five-justice Crawford majority (the plurality plus Justice
Thomas ) vs. the five-justice 703 majority (the dissenters plus
Justice Thomas)
Edward Imwinkelried, The Gordian Knot of the Treatment of
Secondhand Facts Under Federal Rule 703 Governing the
Admissibility of Expert Opinions: Another Conflict Between Logic
and Law, 3 University of Denver Criminal Law Review 1 (2013)
David Kaye, David Bernstein & Jennifer Mnookin, The New
Wigmore: Expert Evidence § 4.12.7, at 70-72 (2014 Cum.Supp.)
B.
A Weight Attack
METHODS § 11-3 (outflanking the expert)
Contrast out-of-court reports with personally known facts.
Point out that the validity of the opinion therefore depends on the out-of-court
declarant’s credibility.
“So to an extent you have to rely on the truthfulness of . . . .”
Raise doubts about the declarant’s credibility.
–The identity of the declarant: “none other than”
–The timing of the report from the declarant
Underscore the witness’s failure to verify the truth of the out-of-court report.
“You didn’t speak with X yourself. Did you?”
“In fact, you didn’t any attempt to reach X. Correct?”
In summation, argue that the validity of the opinion depends on the credibility of
the case-specific information and that the jury should reject the opinion because
of the common-sense doubts about the reliability of the information.
____________________________________________________________________________
VIII. TARGET #5: THE MANNER IN WHICH THE EXPERT APPLIED THE GENERAL
THEORY OR TECHNIQUE TO THE CASE-SPECIFIC INFORMATION
Edward J. Imwinkelried, The Debate in the DNA Cases Over the Foundation for the
Admission of Scientific Evidence: The Importance of Human Error as a Cause of
Forensic Misanalysis, 69 Washington University Law Quarterly 19, 25-27 (1991)(the
lessons from proficiency studies)(hereinafter cited as Forensic Misanalysis)
A.
An Admissibility Attack
METHODS § 5-6
1.
The law
The common law
Forensic Misanalysis, supra
Restyled Federal Rule of Evidence 702(d)
2.
Proof of proper test procedure
The scientific working groups
ASTM International
Operators’ manuals issued by the manufacturer of the instrumentation
used by the expert (James Shellow of Milwaukee, one of the pioneers of
the “chemical defense” in drug prosecutions)
3.
The tactics
The sequence of voir dire or cross-examination
B.
A Weight Attack
METHODS § 12-10
1.
An example: errors in reasoning
Reasoning by mental health experts
The Feigner criteria
Jules Gerard, The Usefulness of the Medical Model to the
Legal System, 39 Rutgers Law Review 377 (1987)
The American Psychiatric Association, The Diagnostic and
Statistical Manual (5th ed. 2013)
Reasoning by toxicologists
Differential diagnosis (etiology)
Giannelli et al., supra, at § 20.06[b], at 358-62 (the need to
take steps such as the administration of diagnostic tests to
eliminate plausible, alternative causes to support a reliable
opinion as to special causation)
____________________________________________________________________________
IX.
TARGET #6: THE WITNESS’S FINAL OPINION ABOUT THE RESULT OF
APPLYING THE MAJOR PREMISE TO THE MINOR PREMISE
A.
An Admissibility Attack
METHODS § 6-6[f]
Suppose that the final result is a measurement such as a measurement of a
subject’s breath alcohol concentration. Metrology is the study of measurements.
The most fundamental tenet of metrology is that all measurements are uncertain.
The “hot button” issue is whether the proponent’s testimony about a measurement
is inadmissible unless it is accompanied by an arithmetic indication of the
measurement’s ucnertainty such as a confidence interval.
Donald P. Land & Edward J. Imwinkelried, “Confidence Intervals: How
Much Confidence Should the Courts Have in Testimony About a Sample
Statistic?,” 44 Criminal Law Bulletin 257 (2008)
The standard error, the dispersion of the measurements
The confidence coefficient
The construction of the interval (upper and lower boundaries)
The 2009 N.R.C. report, supra
The English Law Commission
Kaye, Bernstein & Mnookin, supra, at § 7.6.5, at 102
Memorandum Decision Motion to Suppress, Washington v. Weimer, No.
7036A-09D (Snohomish Cty. Dist.Ct., Wash. Mar. 23, 2010)
Order Suppressing Defendant’s Breath Alcohol Measurements in Absence
of a Measurement for Uncertainty, Washington v. Fausto and Ballow, No.
C076949 and No. 9Y6231062 (King Cty. Dist.Ct., Wash. Sep. 21, 2010).
Washington v. King County District Court, Western Division, 175
Wash.App. 630, 307 P.3d 765 (2013)
B.
A Weight Attack
METHODS § 13-10 (the lack of data needed to properly evaluate the significance
of the test result)
The lack of population frequency data
A trace evidence “match”
The lack of a baseline for the population
So-called symptoms in child sexual abuse accommodation
syndrome (CSAAS)
____________________________________________________________________________
X.
TRIAL STRATEGY
A.
Admissibility Attacks
Should you attack every target which suffers from a weakness?
B.
Weight Attacks
1.
Should you attack every target which suffers from a weakness?
2.
If you select a single target, should you mount more than one attack on
that target?
XI.
CONCLUSION: THE DAUNTING TASK OF ATTACKING SCIENTIFIC EVIDENCE
By the time of trial, you should have refined your attack to a relatively narrow point.
If so, by intensive study it is quite possible for you to know as much or more than the
opposing expert about that discrete topic. Habush, supra, at 1-5; Rogers, CrossExamining the Expert Witness, 21 Defense Law Journal 491, 494 (1972).
It is comforting to realize that in the final analysis, the scientific method is essentially
“commonsense writ large.” Karl Popper, The Logic of Scientific Discovery 22 (1959)