Despite all the CSI crime shows on TV that hype definitive laboratory evidence, science isn’t always an exact science. In fact, several types of evidence have been proven to be faulty and one of the core problems is that it takes fallible human judgement to make the final call about “facts.”
But that didn’t prevent FBI and FBI-trained analysts from persuading numerous juries across the country that the agency’s hair comparisons carried similar certainty to DNA evidence. Mistakes have led to erroneous convictions and innocent people spending decades in prison for offenses they did not commit.
Unscientific methods
Whistleblowers have come forward and revealed that an FBI laboratory routinely gave testimony backed by scientific misconduct and flawed hair analysis. The testimony helped prosecutors secure convictions during the 1980s and 1990s. Hair samples were, in some instances, so grossly mishandled they were attached to Post-It notes and snail mailed.
Among the common errors that occurred included examiners that claimed or implied they had a “match” and that all others could be excluded based on the hair sample. Hairs are not unique to the same standard as DNA or fingerprints. Some experts cited statistical likelihood that the hair came from a unique source. There is no information about how many people have identical hair. Some testimony claimed credibility based on the volume of hairs examined and cases available for comparison. No data hair base exists.
Failure to ensure justice
In one case, a defendant was convicted of sexual assault on the weight of expert hair comparison testimony even though six witnessed placed him more than 100 miles away at the time of the attack. He was sentenced to more than 240 years as a repeat offender. DNA analysis appears to contradict the guilty finding. However, what may be even more disconcerting is that state and FBI officials have not adequately revisited cases or notified people with hair-related convictions.
In 2014, the FBI came under fire for not following up with prosecutors and making sure defendants received notification about the error-filled process. The U.S. Office of Inspector General reported that only 15 out of 402 cases notified defense attorneys. In one instance, a defendant was notified more than 10 years after the fact.
In conjunction with the New York-based Innocence Project and the National Association of Criminal Defense Lawyers, more than 3,000 cases are under review and 90 percent of them “exceeded the limits of science.” Some hair cases are being fast-tracked and several convictions have been overturned based on more reliable DNA comparisons.
