The criminal justice system is still suffering from decades poor forensic evidence. One of those fields, microscopic hair comparison review, has been in the news lately. The FBI has been reviewing cases where their experts gave testimony about supposed hair matches. They found that in over 95 percent of the cases reviewed the FBI’s own forensic examiners overstated the forensic matches.
It is unfortunate that there has not been more of an outcry over this story. It is bad enough that innocent people have been sent to jail. There is no other way to describe this but as a tragedy. We know people have spent years, even decades, in jail for crimes they have not committed. It also means that law enforcement stopped looking for the person who actually committed these crimes. Perpetrators likely remain free, committing more crimes, because the law enforcement agency stopped investigating.
The problem with hair analysis is it is not scientific. It is subjective. When comparing two strands of hair, the identifiable characteristics of each strand are limited. Usually, what can really be determined by looking at a hair under a microscope is its color. That might, for example, narrow the field of suspects if the police think the perpetrator has red hair, but that strand of hair cannot definitely be said to come from any one person (unless there is DNA attached).
For decades FBI analysts were testifying in court that they could identify matches, sometimes going so far as to say they could positively identify them. Local forensic agencies followed the FBI’s lead. Countless people have been wrongly convicted, but the wheels of justice have been slow to reverse the wrongfully convicted.