Fun Fact!
Cops & courts use and have used lots of bogus science to wrongfully convict peopleThere have been many "scientific" tests used by the state to wrongfully convict people. While the nature of our criminal justice system is based on conflict between two sides, the federal government wields incredible resources to develop tools - infrared cameras, sophisticated wiretaps, methods of tracking people's finances - to nail people. Including, for example, tools which are later found to be completely invalid.
One of those tools was hair analysis. This was before DNA testing was widely in use, and I believe was still in vogue up to the 1980s. An expert in the field would examine a hair and determine the race of the person from whom it came, and could sometimes even match it to a suspect's hairs. And while there seems to be some correlation between race and hair type, this is obviously not a tool which should be used to put people in jail. Which it was.
Another test was bite analysis. If someone was assaulted and bitten (apparently common in sexual assault), experts (the same ones?) could look at the bite marks and compare them with a suspect's to see if they were a match. God help me here, I'm trying my damnedest not to put quote marks around every third word in this intro.
And before we go on to the latest debunked forensic pseudo-science, a small tangent. Up through the 70s, some women in the South were forced to undergo sterilization - sometimes without their knowledge. I first heard about it reading about civil rights pioneer
Fannie Lou Hamer, who herself was sterilized without her knowledge. Well, there's finally something of substance written about this, in the Winston-Salem Journal. Check out the series "
Against Their Will."
And now, without further ado...
November 21, 2003
THE NATION
FBI's Crime Scene Bullet Analysis Test FlawedThe technique, used in hundreds of convictions, does not provide the
specific match that examiners had believed, a science panel says.
By Charles Piller, Times Staff Writer
A panel of government scientific advisors has found that an FBI forensic
technique long used to link bullets with assailants is scientifically
flawed and potentially misleading to juries — a finding that could affect
hundreds of past convictions.
The method, which measures the likelihood of a chemical match between
bullets found at crime scenes and those found in the possession of a
defendant, has been used for more than three decades in criminal cases
involving gun violence. The Times obtained a draft of key sections of the
report, which is expected to be formally released by the National Research
Council in early December.
"In the future, it would be very difficult for prosecutors to get that kind
of evidence admitted," said William C. Thompson, a professor of law and
criminology at UC Irvine. "It raises substantial concerns about the
viability of convictions obtained based on such statements in past cases."
Thompson called the report "a slap in the face of the FBI."
A spokesperson for the FBI in Washington said the agency would not comment
on the report until it was finalized.
The National Research Council, based in Washington, also would not comment
on the report, but a source close to the study indicated that its primary
conclusions would stand in the final version.
The report is "a very substantial development — a significant indictment of
the technology," said David L. Faigman, a professor of law at UC Hastings
College of the Law in San Francisco. "The NRC has such prestige that I
can't imagine that a court, after the NRC report, would permit this kind of
testimony."
The chemical analysis of bullets found at crime scenes involves analyzing
the material for traces of contaminants or additives, such as tin and
antimony. The precise amount of contaminants is then compared to the
results from bullets found in a suspect's possession.
FBI examiners have often stated or implied in court that a bullet can be
traced to a specific manufacturing batch — even to a particular box. For
example, John P. Riley, then an FBI lab examiner, testified at a 1988
murder trial: "From my 21 years of experience doing bullet-lead analysis, I
can determine if bullets came from the same box of ammunition…. That is the
case that we have here."
His testimony played a key role in the conviction of the defendant, who was
later executed.
In more recent cases, FBI examiners have tended to match a particular
bullet not to a single box, but to a group of boxes manufactured on or
around the same day at the same factory.
The technique has offered a way to solve crimes involving gun violence when
no gun was found. It has strengthened weak cases in which evidence is
scarce or circumstantial.
A Times investigation of the technique published in February suggested that
the FBI's use of lead-analysis evidence might have been based on faulty
assumptions that greatly overstated its scientific significance.
After criticism from independent experts, the FBI commissioned the
lead-analysis study from the National Research Council, considered the
nation's preeminent group for assessing science and technology. The panel,
which included experts in chemistry, law and statistics, studied the method
for nearly 10 months.
The panel substantially agreed with recent research indicating that bullets
from the same source of lead can significantly vary in their chemical
makeup, and bullets from different sources — even those manufactured years
apart — can share nearly identical amounts of trace elements.
The finding contradicted some prosecutors' depictions of each batch of lead
as being unique, like a snowflake or fingerprint. The study suggests that
the number of "matching" bullets is impossible to determine and could be in
the tens of millions or far higher — dramatically reducing the significance
of a match.
"References to 'boxes' of ammunition in any form should be avoided as
misleading under Federal Rule of Evidence 403," the panel concluded.
"Detailed patterns of the geographical distribution of ammunition are
unknown, and as a result, experts should not testify as to the probability
that the crime-scene bullet came from the defendant."
The draft report also questioned the statistical basis of the FBI's
analysis, which had been criticized by the bureau's own statistical
consultant as scientifically unsupported. The panel proposed new research
and changes in which statistical tests are used. Although the panel stopped
short of condemning the technique outright, it sharply disagreed with how
FBI examiners have often represented bullet evidence in court.
"If we were to embrace this report, then the test really has very little
utility," said John Thornton, professor emeritus of forensic science at UC
Berkeley. "It's really watered down the significance and the impact."
(And look here for how the anti-choice folks remember Fannie Lou Hamer. Very smooth work.)