WASHINGTON — The Justice Department, stung by reports
that F.B.I. scientists have often vastly overstated their level of
certainty in matching hair samples and other evidence, issued new rules on
Friday meant to ensure that the experts’ testimony in criminal cases is
“supported by sound science.”
The new rules, which have yet to be made final, are the latest in a
series of steps that the Obama administration has taken to address the
problems, including those revealed in a preliminary review last year of F.B.I.
testimony in hair-sample cases.
That analysis, which examined 268 criminal cases from 1985 to 1999,
found flawed testimony in more than 95 percent of them. More than a dozen of
the defendants have been executed or have died in prison.
The guidelines issued on Friday provide a framework
for F.B.I. testimony involving seven types of forensic evidence, including body
fluid, fingerprints and footprints. They seek to inject a more realistic
measure of doubt in courtroom testimony.
No longer, for instance, would F.B.I. forensic
witnesses be allowed to testify that there was a “zero error rate” in comparing
one fingerprint to another, or that one sample of blood was a certain match to
another.
Instead, they would be
required to testify how likely or unlikely a match was found to be, within an
“acceptable range of opinions.”
Once the rules are formally adopted, they “will
clarify what scientific statements our forensic experts may — and may not — use
when testifying in court and in drafting reports, in turn strengthening the
integrity of our system over all,” said Sally Q. Yates, the deputy attorney
general.
A spokesman for the F.B.I. laboratory in Quantico,
Va., declined to comment on the guidelines, which would also apply to the Drug
Enforcement Administration and the Bureau of Alcohol, Tobacco, Firearms and
Explosives.
While the guidelines are highly technical, the
existing rules have had a real-life impact in many criminal cases.
The Justice Department has offered new testing to
hundreds of surviving defendants in cases marred by errors in hair-sample
testimony, and a few of them have already been exonerated. The department is
continuing to examine whether errors were made in testimony involving other
types of forensic evidence as well.
Peter Neufeld, a founder of the Innocence Project, a defense advocacy group that has pushed for greater
scrutiny of F.B.I. forensic methods, said the new guidelines were a welcome
step.
“It’s remarkable that they didn’t do this for many
years,” he said. “But frankly, they should be applauded for recognizing that
mistakes were made and that they have a duty to correct those mistakes.”
The Justice Department is giving outside scientists
and members of the public a chance to weigh in on the proposal before it is
made final later this year.
Mr. Neufeld said he
wished that the Justice Department had brought in outside scientific feedback
long before this, rather than relying on in-house specialists. He predicted
that outside scientists, once they finish their review of the framework
proposed on Friday, would have “significant and substantial concerns.”
Questions have flared for years over the accuracy of
the F.B.I.’s courtroom testimony involving some types of forensic evidence. A
2009 study by the National Research Council found “no scientific support” for
positively identifying a suspect from a hair sample, and additional scientific
reviews and news media reports since then — most notably in The Washington Post— have raised still more questions.
The Justice Department plans to release a second set
of proposed guidelines this summer regarding courtroom testimony involving DNA,
explosive devices, hair analysis and handwriting.
Scientific experts consider DNA — which first became
widely used in courts in the 1990s — to be the only near-certain indicator of a
forensic match. While other types of physical evidence are considered helpful
in comparing samples and ruling suspects in or out of an investigation, they
are considered far less certain.
No comments:
Post a Comment