Fallen forensics: Judges routinely allow disavowed science in court
BOSTON» Two hairs that looked like the victim’s, some dirt on a truck like that taken from the crime scene, a pattern on the bumper that resembled a design on the victim’s popular brand of jeans. The case against Steven Barnes in the rape and murder of a 16-yearold girl seemed circumstantial, at best.
So the guilty verdict shocked him.
“I was saying, ‘This can’t be happening. You can’t convict somebody on similarities, perhaps or maybes,’” Barnes said.
He spent the next 20 years in prison before DNA testing exonerated him, becoming one of hundreds of people convicted in whole or in part on forensic science that has come under fire during the past decade.
Some of that science — analysis of bite marks, latent fingerprints, firearms identification, burn patterns in arson investigations, footwear patterns and tire treads — was once considered sound but is now being denounced by some lawyers and scientists who say it has not been studied enough to prove its reliability and in some cases has led to wrongful convictions. Even so, judges nationwide continue to admit such evidence regularly.
“Courts — unlike scientists — rely too heavily on precedent and not enough on the progress of science,” said Christopher Fabricant, director of strategic litigation for the Innocence Project. “At some point, we have to acknowledge that precedent has to be overruled by scientific reality.”
Defense lawyers and civil rights advocates say prosecutors and judges are slow to acknowledge that some forensic science methods are flawed because they are the very tools that have for decades helped win convictions.
Rulings in the past year show judges are reluctant to rule against long-accepted evidence even when serious questions have been raised about its reliability:
• A judge in Pennsylvania ruled prosecutors can call an expert to testify about bite marks on a murder victim’s body, despite 29 wrongful arrests and convictions nationwide attributed to unreliable bite mark evidence since 2000.
• A Connecticut judge allowed prosecutors to present evidence that a footprint was made by a specific shoe, despite a 2016 finding that such associations are “unsupported by any meaningful evidence or estimates of their accuracy.”
• In Chicago, a federal judge rejected a request to exclude testimony of government experts to describe firearm and tool-mark comparisons they performed on bullets collected at crime scenes in the trial of gang members.