US judge urges skepticism on forensic evidence
Gertner says she’ll expect defense lawyers to challenge its validity
By Jonathan Saltzman, Globe Staff | March 29, 2010
“CSI” may make for gripping television, but US District Court Judge Nancy Gertner says forensic evidence isn’t everything it’s cracked up to be.
In a move that some legal scholars said may be the first by a federal judge, Gertner has ordered defense lawyers and prosecutors not to assume that evidence routinely accepted in the courts for decades is reliable. Defense lawyers, she wrote, should vigorously challenge fingerprints, bullet identification, handwriting, and other trace evidence, and prosecutors should be prepared to show it is valid.
“In the past, the admissibility of this kind of evidence was effectively presumed, largely because of its pedigree — the fact that it had been admitted for decades,” Gertner wrote in a March 8 order. “As such, counsel rarely challenged it, and if it were challenged, it was rarely excluded or limited.”
That needs to change, she said. A critique last year by the National Academy of Sciences, she noted, concluded that forensic evidence used to convict thousands of defendants for nearly a century is hardly the infallible proof of police procedurals on television. Too often, the study found, it is the product of sloppy practices that should be improved and standardized.
Spurred by the report and criminal cases she has presided over, Gertner wrote that the validity of such evidence “ought not to be presumed” and that defense attorneys should contest it at pretrial hearings, or explain why they do not. She will allow the evidence to go before a jury only if it meets sound scientific principles.
Defense lawyers and advocates for people who have been wrongly convicted of crimes welcomed Gertner’s order.
“It’s a wakeup call not only to other judges and to prosecutors but frankly to defense attorneys who for years — despite the rising tide of scientific reports indicating that many of the so-called tried-and-true disciplines were not in fact so true — rarely did their homework to mount serious challenges,” said Peter Neufeld, a cofounder of the New York-based Innocence Project. The nonprofit group uses DNA evidence to exonerate wrongly convicted prisoners.
Neufeld, who testified before the panel of scientific and legal experts that produced last year’s report on forensic evidence, said a recent study he co-wrote for the Virginia Law Review found that flawed forensic testimony contributed to 60 percent of 137 wrongful convictions later overturned through DNA evidence. That makes misapplied forensic evidence the second-leading cause of wrongful convictions, behind eyewitness misidentification, he said.
A spokeswoman for US Attorney Carmen M. Ortiz of Massachusetts declined to comment on Gertner’s order.
Jennifer Mnookin, a professor at UCLA’s School of Law and leading scholar on expert and scientific evidence, said she was unaware of any other federal judge who has issued such an order, although judges have refused to let shaky scientific evidence go before juries after pretrial hearings.
Mnookin said forensic testimony is highly persuasive to juries but that the February 2009 study by the National Academy of Sciences, the nation’s most prestigious scientific body, underscored that the evidence often does not meet the basic requirements of good science.
She said, for example, that fingerprint experts often make extravagant claims on the stand, such as that a latent fingerprint recovered at a crime scene could only have come from the defendant and no one else in the world.
Gertner, who is generally popular with the criminal defense bar but viewed skeptically by some officials in law enforcement, has long been critical of such claims.
In 1999, she held that a handwriting expert could testify to similarities between handwriting samples but not give an opinion about whether the same person wrote both notes. Six years later, she issued a similar ruling concerning ballistics, blocking a Boston police sergeant from testifying that marks on shell casings proved they came from a recovered pistol and no other firearm.
In recent years, the reliability of some forensic evidence has been attacked because experts misinterpreted it or because the science behind it was discredited.
In 2004, for example, the National Academy of Sciences issued a report discrediting the FBI technique of matching the chemical signatures of lead in bullets at crimes scenes to similar bullets possessed by suspects. The FBI discarded the technique.
Also in 2004, a prison inmate, Stephan Cowans of Roxbury, was exonerated in the 1997 gunshot wounding of a Boston police sergeant after law enforcement officials acknowledged that a thumbprint on a glass mug found near the crime scene had been misidentified as his. In the wake of the blunder, the city shut down the police fingerprint unit until it was overhauled.
John H. Cunha Jr., a Boston lawyer who failed to persuade the state Supreme Judicial Court in 2005 to bar fingerprints analysis from being presented in all state criminal trials until it was subjected to rigorous scientific scrutiny, said he hopes Gertner’s order means judges will be more vigilant about letting juries hear forensic testimony.
“Just because something’s been around for a hundred years doesn’t mean it’s reliable. Astrology has been around for centuries,” he said. “The stakes are too high in our society to be using junk science and putting it before juries which think that it’s gold.’