New York Times
May 11, 2001

Junk Science, Junk Evidence


or much of the 20th century, prosecutors served up the forensic scientist as a source of certainty amid fleeting glimpses, shaky memories and disputed confessions. Or so it seemed.

This week, Jeffrey Pierce was released from an Oklahoma prison after DNA tests proved that he had served 15 years for a rape he did not commit. The case against him had been cinched by Joyce Gilchrist, a supervisor in the Oklahoma City police laboratory, who said that samples of Pierce's hair matched those collected at the crime scene.

In Texas, Michael Blair was sentenced to die for murdering a little girl in 1993 incriminated, prosecution experts said, by hairs found in his car and near the child's body. In March, a new technique for extracting mitochondrial DNA directly from the shafts of hair proved the hairs did not come from Mr. Blair or the girl. If we care about justice, money has to be found to do such tests everywhere.

Conventional hair analysis, based on looking at one strand of hair under a microscope and comparing it to another, is subjective junk science. Hair experts have never been able to agree on consistent criteria for "associating" a suspect with an unknown hair, nor have they produced persuasive data showing the probative value of these "associations." In the early 1970's, the federal government sponsored a proficiency-testing program for 240 laboratories. The labs did so poorly on hair analysis that flipping a coin would have saved a great deal of time, at no cost to accuracy.

Thousands of prisoners are serving time based on this bogus science, which often props up wobbly eyewitness testimony or dubious tales peddled by jailhouse snitches. Among the first 74 prisoners exonerated by DNA testing over the past decade, 26 were implicated, in part, by hair analysis.

Unsound techniques survive because forensic science has been woven into the culture of prosecution and insulated from routine quality assurance standards we impose on medical testing labs. Ms. Gilchrist is now under investigation after the Federal Bureau of Investigation found that she gave misleading testimony in five of eight cases that it reviewed. Oklahoma prosecutors used her work in thousands of cases, including 23 that resulted in sentences of death. Despite complaints from her colleagues, she was promoted.

In Chicago, a police lab analyst, Pamela Fish, left out exculpatory serological results in testimony at a 1992 rape trial, contributing to a wrongful conviction. In 1999, the defendant was exonerated by DNA tests. Questions have now been raised about Ms. Fish's conduct in a 1986 murder case.

In West Virginia, the infamous Fred Zain, chief serologist for the state's crime laboratory, is finally going to trial on fraud charges after the state's Supreme Court found that he had offered false testimony in hundreds of cases. An F.B.I. hair and fiber examiner was castigated by the agency's inspector general for sloppy science, but there has been no systematic reexamination of his cases.

Too often, forensic laboratories are run by law enforcement officers in lab coats. The laboratories cannot be allowed to operate as arms of police departments and prosecutors' offices. They need to be independent agencies, serving as fact finders for both the prosecution and the defense.

There is a model for improvement. The 1988 Clinical Laboratory Improvement Act provided accountability for laboratories that perform medical tests. A mistake in health tests can have dire results not only for the patient, but also for the lab, which risks losing accreditation.

In forensic laboratories, by contrast, few are held accountable for a bad practice or botched results. Under this system, the innocent pay, not the criminals.

Copyright 2001. New York Times Company. All rights reserved.

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