By JOHN SOLOMON, Associated Press Last Updated 3:11 p.m. PST Friday, November 21, 2003
WASHINGTON (AP) - The National Academy of Sciences has concluded that a
technique the FBI has used for decades to match bullets to crimes is
flawed, a position that could hand defense lawyers a new avenue of
attack against the world's most famous crime lab.
The academy's study, to be released early next month, makes about a
half-dozen recommendations for changing the way the FBI matches bullets
by their lead content and strongly urges bureau experts to more
precisely describe the significance of their findings in court.
The findings, which are in final draft form, were described to The
Associated Press by several people involved in the study. They would
speak only on condition of anonymity.
The study's publication next month could open the door to hundreds,
even thousands of appeals, and give defense lawyers in future cases new
ammunition for undermining expert testimony.
The National Association of Criminal Defense Lawyers said Friday it
will urge its members to aggressively seek appeals in past cases where
bullet lead analysis was done. "There are people sitting in jails
who were wrongly convicted because of this junk science," spokesman
Daniel Dodson said.
Barry Scheck, the group's president-elect who as a lawyer has worked
to free prisoners convicted by errant science, praised the FBI for
seeking the review. "The FBI should go through their own case files
and reopen every case where this kind of analysis was done," he
said.
Senate Finance Committee chairman Charles Grassley, R-Iowa, urged the
academy to quickly release its findings. "Flawed forensic
techniques risk letting the guilty go free and sending the innocent to
prison. This report needs to be made public so Congress and others can
evaluate what's happened and hold the FBI accountable," Grassley
said.
FBI officials said they had not seen the report and would not
comment.
"I cannot comment on a draft report that is still being peer
reviewed and subject to change," added National Academy of Sciences
spokesman Bill Kearney.
Officials familiar with the report said it is finished, save for an
issue involving statistical analysis.
The findings are the latest in a string of controversies and
embarrassments this year to hit the FBI lab, which pledged to remake
itself after a scandal in the 1990s over bad science.
One FBI lab scientist involved in lead bullet analysis has pleaded
guilty to giving false testimony, another employee has admitted to
improper DNA testing and long-secret documents have emerged this year
suggesting there were undisclosed problems with the FBI lab's work in
the Oklahoma City bombing case.
FBI Lab Director Dwight Adams asked for the academy study this year
after one of the bureau's former metallurgists began questioning the
validity of the science used by the lab to match bullets by their lead
content. The academy, chartered by Congress and privately run, is widely
respected.
The science is based on the theory that bullets from the same lead
batch share a common chemical fingerprint. Adams told AP last spring he
was confident the study would vindicate the bureau's science.
But the study, according to those who have seen it, strongly
challenges some of the assumptions and techniques that the FBI has used
since around the time of John F. Kennedy's assassination.
For instance, it urges the bureau to stop a practice known as data
chaining that its chemists have used in the past to improve the
likelihood they could match two bullets through chemical analysis.
In data chaining, scientists can conclude that if the lead content of
bullet A matches bullet B, and bullet B's content matches bullet C, then
it is safe to testify that bullet A and bullet C are a match even if
their test results don't match identically. Said another way, the FBI
can match two slightly dissimilar bullets if they can find a third -
from a manufacturer, for instance - that matches both.
Charles Peters, an FBI expert witness in cases involving bullet lead
comparison, testified recently that data chaining - the technique
disavowed by the academy - was important.
"I'm a fan of chaining," Peters testified in April in a
case in Alaska. "If we had great precision, really good precision
... and we didn't do something like chaining, or something like that,
nothing would ever match."
Citing examples of inconsistent or contradictory testimony by FBI
experts in courtrooms, the study also recommends that lab analysts' work
and testimony be reviewed by a colleague to ensure accuracy and
precision, the sources said.
And it strongly urges FBI expert witnesses to more narrowly and
precisely describe the scientific significance of lead bullet findings,
especially given that the bureau does not have information on how many
bullets from the same lead source may have been distributed in an area
around a crime scene.
The FBI has been the prime practitioner of lead bullet comparisons in
the United States, and has used them for decades. A database of lead
test results kept by the agency had more than 13,000 samples in the late
1990s, FBI officials have told the AP.
The FBI most commonly identifies bullets recovered from a crime by
firing new bullets from the suspect's weapon and comparing the markings
left by the gun barrel on the test bullet with the crime scene bullet.
But that method only works when the crime scene bullet is in good shape
or if police have the suspect weapon.
In cases where recovered crime scene bullets are fragmented or
disfigured or a suspect's weapon is unavailable, the FBI has turned to
chemical analysis to try to determine whether the bullet's lead content
is comparable to the same manufacturer, lead source or box of bullets
connected to the suspect.
The FBI had warnings prior to the academy study. Retired FBI
metallurgist William Tobin published research challenging the very
premise of the FBI's science. And Iowa State University conducted
research that drew similar conclusions.
"The fact that two bullets have similar chemical composition may
not necessarily mean that both have the same origin," that study
said.
