A review of more than 21,000 cases has revealed twenty-seven death penalty cases in which the FBI’s forensic experts may have exaggerated the scientific conclusions that could be drawn from a so-called “match” between a hair found at the scene of a crime and hair of the defendant. It is not known how many cases involve errors, how many led to wrongful convictions, or how many mistakes may now jeopardize valid convictions. Those questions will be explored as the review continues.
The discovery of the more than two dozen capital cases promises that the examination could become a factor in the debate over the death penalty. Some opponents have long held that the execution of an innocent person would solidify doubts about capital punishment. But if DNA or other testing confirms convictions, it would strengthen supporters’ arguments that the system works.
At least three Florida men, including DNA exonerees Wilton Dedge and William Dillon, were convicted based on, among other things, testimony provided by John Preston, who claimed that his dogs could perform feats of forensic detection far beyond the abilities of other investigative dogs. Preston testified in each case that his dog picked up the scent of the defendant at the scene of the crime, testimony that all but sealed their fate. By now, though, his claims have been thoroughly discredited by experts in the field of scent tracking, media reports, multiple state supreme courts, police training manuals, and law review articles. This leads to the question of why Preston was ever considered reliable in the first place and why more was not done to do a re-review of all cases in which Preston and fraudulent dog handlers like him have testified.
Advocates for defendants and the wrongly convicted called the FBI’s reexamination of possibly faulty forensic conclusions a watershed moment in police and prosecutorial agencies’ willingness to re-open old cases because of scientific errors uncovered by DNA testing. “We didn’t do this to be a model for anyone,” said FBI general counsel Andrew Weissman. “When there’s a problem, you have to face it, and you have to figure how to fix it, move forward and make sure it doesn’t happen again.” FBI Laboratory director Chris Hassell has said that the review will be used to improve lab training, testimony, audit systems, and research.
The review is a huge step forward to improving the criminal justice system and the rigor of forensic science in the United States. Faulty forensics and science is one of the leading causes of wrongful convictions, and a revised approach to forensics could help to reduce that number of miscarriages of justices before the occur. Hopefully we’re not far off from reforms in other leading causes, such as eyewitness identification or snitch testimonies.