Physical evidence
Introduction
Examples
Park City man held in 17-year killing spree
(L.A. Times and Wichita [KS] Eagle, 2/27/05, 6/27/05, 8/19/05)
On 2/25/05 Wichita Police arrested Dennis Rader, 59, a
Park City code enforcement officer, for ten killings between
1974 and 1991. Rader left semen at each scene. He taunted
police and the media with notes signed “BTK” (bind, torture,
kill).
Despite collecting DNA from 5,000 persons there was little
progress until recently when, after 25 years of silence, the
killer resumed sending letters and leaving victim’s belongings in public places. Surveillance
footage showed a Park City animal control van. A computer disk he left was traced to a computer in
Rader’s church. Crime scene DNA was matched against a sample of Rader’s daughter’s DNA.
Rader, the leader of his local church’s lay group, was a zealous officer. “We always said he was
invisible because he was most likely so ordinary,” said a retired
“After killing [a] neighbor,
detective. “As it turned out, he was exactly ordinary. He went to
Rader took her body to his
work. He went to church. He went to Boy Scouts. He did family
church and photographed it
things. Just an ordinary guy.”
on the altar. Then he hid
her body, changed into his
Scouting uniform and went
off to chaperon a camping
trip.”
On June 27, 2005 Rader pled guilty to the ten slayings and
“without emotion” recited details about each. Rader said the
“projects” were done for sexual gratification. He received ten
consecutive life sentences.
Robert Blake – the murder
of Bonnie Lee Bakley
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On May 4, 2001 about 7:30 pm Blake and Bakley
had dinner at Vitello’s restaurant. Blaked parked
1½ blocks away, by a dumpster.
They left about 9:30 pm. Minutes later, Blake, looking flustered, returned
and said he had left his gun behind. He drank two glasses of water and left.
Blake said he walked back to his car and found Bakley shot. He ran to a
nearby house and its resident called 9-1-1. They went to Blake’s car. The
resident tried to stop the bleeding. Blake ran back to the restaurant,
supposedly to look for a doctor.
The murder gun was later found in the dumpster by Blake’s car.
Two stuntmen testified that Blake asked them to kill his wife but they refused.
Blake purchased telephone call cards so they could call each other using pay
phones. Blake told many persons how much he hated the victim.
Blake claimed that Bakley, who once made her living hustling, was being
stalked, possibly by a disgruntled ex-client.
Why was Blake acquitted?
The jury speaks
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Jury foreman Thomas Nicholson
said the case was “flimsy” and
“disjointed”. “You couldn't put the
gun in his hand....There was no
[gun shot residue], no blood on his
clothing — there was nothing.” (Court TV)
Juror Lori Moore: “We just didn't have enough evidence to say
whether or not he did it.“ (Court TV)
Juror Cecilia Maldonado said that TV shows like CSI created a higher
expectation: “I just expected so much more," she said. Jurors wanted
“more-convincing evidence, such as conclusive gunshot residue on
Blake's hands, or a fingerprint on the murder weapon.” All jurors but
one also thought that the stuntmen were lying.
L.A. County D.A. calls Blake
jury “incredibly stupid”L.A.Times, 3/24/05
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On 3/24/05 the Los Angeles Times reported
that L.A. County District Attorney Steve Cooley
called the Blake jury “incredibly stupid” for
acquitting “a miserable human being” who was obviously “guilty
as sin”.
According to Cooley, prosecuting celebrities in Los Angeles is
very difficult. He predicted that his office would face similar
challenges in the next celebrity murder trial, of record producer
Phil Spector.
Cooley pointed to shows such as “CSI” as being part of the
problem, as they raise “false expectations” about the evidence
that can be presented.
A current case:
the murder of Imette St. Guillen
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On 2/25/06 Imette St. Guillen, a graduate student at
John Jay College of Criminal Justice was found
strangled. She had been sexually assaulted.
St. Guillen was last seen late the previous evening in a bar. The bar’s
bouncer, Darryl Littlejohn, had escorted her outside at closing.
Littlejohn, a parolee, was apparently the last person who saw the
victim alive. He was later accused of her murder.
Use the video in the next slide to answer these questions:
– What physical evidence ties Littlejohn to the slaying?
– Assuming that Littlejohn had no connection to the bar or to the
victim, would the physical evidence have led to him?
– Assuming that your answer is “yes”, would the physical evidence
be enough to arrest Littlejohn? To convict him?
But on November 18, 2005 . . .
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By a vote of 10-2, a civil court jury found
Robert Blake responsible for killing his
wife, Bonnie Lee Bakley. On a 9-3 vote
they awarded the plaintiffs – their daughter and Bakley’s three
other children – $30 million.
According to jurors the key were inconsistencies between
Blake’s testimony, what he had told police and what other
witnesses had to say.
Blake did not testify during the criminal case. But he had to
testify in the civil trial, thus making his believability an issue.
And that, according to Duke Law School professor Erwin
Chemerinsky, turned the tide. “Here the jury didn't believe him.“
Los Angeles Times, 11/18/05
April 2006:
The Duke scandal
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In April 2006 two Duke
lacrosse players were
arrested for allegedly raping
an exotic dancer who was
paid to perform for the team
at a frat house
DNA samples from the entire team were taken, but no match
was made to biological samples taken from the complainant
Defense lawyers called it a vindication
Prosecutors said that the absence of a suspect’s DNA did not
prove there was no rape and suggested condoms might have
been worn
Problems with physical evidence
The “C.S.I.
effect”
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"There is no doubt that there's increasing
expectation by jurors..." said an Oregon
prosecutor. “Prosecutors across the
country are very concerned about this.“
Blake jurors "seemed very dismissive of
circumstantial evidence....Well, guess
what? In most cases…you don't have
physical evidence.“
There is "an expectation that people
from the crime labs will have super
technology to resolve a case," said
Barry Scheck, a member of the
O.J. Simpson defense team. But
Scheck thinks the factor here was
simply “an absence of evidence.”
Is forensic science
“scientific”?
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"When you move over to forensic science
[from conventional science] there is
astonishingly little research to test the fundamental assumptions," says Michael
Saks, Professor of Law at Arizona State University.
Saks was interviewed by the Los Angeles Times in connection with the Phil
Spector trial, where prosecution experts testified that blood spatter does not
travel more than three feet, while defense experts said it can go as far as six or
seven feet.
But -- no one had ever shot off a gun inside a living person’s mouth to test a
hypothesis about how far blood spray from the mouth can travel. Defense
experts cited experiments where blood was dripped on a fan. But the actual
experimenter in that study did not testify, probably because his conclusions
were too qualified to be useful to the defense.
One problem, said Saks, is that prosecutors and defense attorneys interview
experts in advance, screening out those who come to unfavorable conclusions.
Then it’s up to the jurors to decide whom to believe.
Excessive confidence in
physical evidence and experts
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In 1984 Ken Marsh was convicted for
beating to death his girlfriend’s 2-year old
son, whom he was babysitting. March
denied doing so and said that the boy fell
and hit his head. Although a detective
agreed, hospital doctors insisted otherwise.
Marsh was prosecuted without police
involvement and convicted of murder.
Marsh refused to plead guilty to a lesser
charge. Even when imprisoned and offered
leniency, he refused to cave in.
In January 2006, after serving 21 years,
Marsh was declared factually innocent and
awarded $756,900. Marsh’s prosecutor still
feels that Marsh is guilty, but San
Bernardino County D.A. Michael Ramos,
who heads the California compensation
board, formally apologized to Marsh.
The saga of
Timothy Masters
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In February 1987 the body of Peggy Hettrick,
36, was recovered from a field in Ft. Collins,
CO. She was stabbed to death with one
“forceful blow” to her back. Her left nipple
and the skin around her vagina were excised with a special instrument, a
procedure that a doctor later said could have only been done by an expert.
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Suspicion quickly fell on a troubled 15-year old boy that lived nearby, Tim
Masters. He admitted riding his bicycle past the body but said he thought it was
a mannequin. A search of his bedroom turned up several knives and, hidden in
the handle of one, a scalpel. He had made hundreds of drawings depicting
violence and torture, including women being stabbed with knives and swords. He
also had sketched a body being dragged in the way that police think the killer
dragged Hettrick and a map of the scene with an “X” showing where the body
was found (Masters said he drew it after the fact in response to a friend’s
question.)
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None of the knives had blood on them. Masters steadfastly denied killing the
woman. He was so small and slight that officers didn’t think he had the strength
to overcome the victim. He was not arrested.
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Eleven years later, in 1998, officers received a report from a California forensic
psychiatrist that the pictures drawn by Masters, including one depicting what
seem to be the stabbing of a vagina, were a “fantasy rehearsal” for a homicide.
Masters was then arrested and, based mostly on the psychiatrist’s testimony
and the drawings, he was convicted of murder. His conviction was upheld on
appeal to the Colorado Supreme Court.
On January 22, 2008 Masters was released after
serving nine years. New results indicated that DNA
found on the victim’s body belonged to another man,
who had been interviewed by police in 1987. He had
denied having any contact with the victim and was
cleared.
Master’s conviction was overturned. Police and
prosecutors agree that the evidence now points to this
other man.
There is no compensation law in Colorado. Disciplinary
actions against the detectives and prosecutors on this case (they are now
judges) for withholding evidence are pending.
Released after two years
and four months
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A 23-year old Marine, Todd Sommer, died
in 2002 at his San Diego home. His death
was first ruled as natural. Tests showed
high levels of arsenic in his organs.
His wife, Cynthia, partied hard after his death, had multiple affairs and used
money from the $250,000 life insurance for breast implants. In January 2007
prosecutors used the arsenic plus evidence that she was “celebrating” instead
of “mourning” to convict her of murdering her husband for his insurance. She
could have gotten life without parole.
However, in December 2007 she was granted a new trial because her lawyer
had incompetently portrayed her as a “model wife,” opening the door for a
rebuttal by prosecutors that the judge felt unduly prejudiced jurors. A new exam
by another lab found no arsenic in the tissues. An expert said that the first
results were probably contaminated and that her husband likely died from
sudden cardiac arrest, a relatively common problem in young people.
She wasn’t retried. On April 18, 2008 Sommer was released on the motion of
prosecutors, who felt that there was now reasonable doubt of her guilt.
However, they insisted that the system worked as intended.
A special concern:
staged events
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Purposeful acts (e.g., arson,
murder, staged car crashes, etc.)
disguised as accidents
Clues:
– Inconsistency between
crime scene and
characteristics of a real
event
– Inconsistent victim and
witness statements
– Inconsistency between
recovered evidence and
what would be found at a
true event
– Same claimants involved in
repeated incidents
Gathering physical evidence
It usually starts with
shoe leather...
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Few cases are solved by physical
evidence alone
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Major exceptions
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Usually need to identify a suspect
first through other means
(witnesses, interviews, etc.)
Excellent latent prints are available and the suspect’s prints are on a
shared system
Sufficient suspect DNA is available and the suspect’s DNA profile is on a
shared system
Must still rule out innocent deposits of fingerprints or DNA
Even when physical evidence is crucial, facts are necessary to “lay the
foundation” for its introduction. Testimony is necessary to:
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Connect the physical evidence to the circumstances of the crime
Demonstrate how and where the evidence was recovered and collected
Demonstrate that the evidence was not altered
Crime scenes
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Definition
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Physical location where
a crime took place
Any location where
evidence of a crime may
be present
Multiple scenes
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Example: Montana
fugitives
What is evidence?
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Anything that might help to
establish whether (if) a crime was
committed, and by whom
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What are the elements of the
crime?
What evidence might be present?
What is native to the location?
What is foreign?
How would the natural
environment have changed if
a crime occurred?
Potentially exculpatory evidence
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Must be collected and disclosed to the defense
Issues in seizing evidence
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Cannot take everything
Limitations
– Resources (time, money, manpower,
analytical, storage capabilities)
Sufficiency of quantity – need “control” samples
– Destructive examination
– Analysis by defense
– Presentation in court
Taking objects that bear evidence
(fingerprints, bullets, bomb fragments,
explosive residue)
Access and inspection
– By officers
– By suspect (necessities of life or business)
“Questioned” and “known”
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Questioned evidence: evidence whose source or
place of origin is unknown
 Objects, prints and impressions, residue,
etc. found on a suspect or at a crime
scene but originating elsewhere
 Latent fingerprints, paint transfers, foreign
dirt, hairs and fibers, DNA
Known evidence: evidence whose
source or place of origin is known
– Things known to be associated with
a suspect or a crime scene
– A known person’s DNA, hair, fibers
from their clothes, tread patterns
from their shoes, paint from their car
“Class” and “individual”
characteristics
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Class: Physical details common to all objects of a certain type
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Individual: Details unique to a particular object, due to wear,
contact with foreign materials, etc.
Documenting the collection process
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Before and after
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Photography
Sketch
Where found
Chain of custody
Recording and labeling
Using “finders”
Alternative collection methods
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Drawings and photos
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Detection and imaging devices
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Permanent features (landmarks;
obstructions to view
Relative positions (buildings, signs
and objects)
Sniffers
X-rays, fluoroscopes
Animals
Physical evidence
is fragile!
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Must be preserved and
protected
Removal – destruction – alteration
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Loss and breakage
Contamination
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Innocent
Purposeful
Transfer between different scenes
Decay
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Evaporation and solidification