Your Favorite TV Crime-Stoppers Are Using Junk Science
The FBI’s embarrassing revelation that flawed microscopic hair analysis overstated findings that were used in 95 percent of the criminal cases they reviewed over two decades is just the tip of the bad-evidence iceberg. The faulty analyses, which contributed to prosecutions that led to 32 death sentences, were found in a review of 342 cases—the FBI still has to review 1,200 more to find out just how many cases may have been incorrectly prosecuted, potentially leading to wrongful incarceration or execution, according to The Washington Post.
As the FBI publicly face-palms and tries to wade backward through erroneous evidence—including one case in which dog hair was presented at trial—it’s a good time to remember that hair forensics is just one of many methods that has inched its way into the “junk science” category.
“The ironic thing is that the public believes the forensic science we’ve got is infallible in the courtroom,” said Mark Godsey, director of exoneration advocacy group the Ohio Innocence Project. “The reality is, it’s the exact opposite. It’s embarrassing and dangerous.”
For people like Godsey who work to fight wrongful convictions, the FBI’s findings were not a surprise. Rather, the report is just the latest strike against the efficacy of many forensic techniques over the last several years. In 2009, leading scientists of the National Academy of Sciences published a report calling into question numerous forensic sciences and calling for increased oversight and research into the problem. DNA testing has helped reveal wrongful convictions that in many cases hinged on questionable forensic methods, helping to prove that many such techniques haven’t undergone rigorous scientific evaluation.
Testing for gunshot residue on suspects’ hands, for example, has proven over time to be unreliable. While swabbing a suspect’s hand and testing for residue might seem straightforward, studies have shown that gunshot residue is often found in the back of police cars and the surface of interrogation tables, which means handcuffed suspects can easily wind up in contact with it even if they’ve never touched a gun.
Bite mark comparisons have also turned out to be questionable. In 1995, Gerard Richardson was sentenced to 30 years in prison for allegedly murdering a woman, in a case where the only physical evidence tying him to the act was a forensic odontologist’s statement that a bite mark on the victim’s body matched Richardson’s teeth. As the Post reported, Richardson was finally released in 2013 thanks to DNA evidence that proved his innocence.
Comparative techniques, such as those used by the doctor reviewing dental records in Richardson’s case, came under particular scrutiny in the 2009 report. Tire treads and shoe prints present similar problems, Godsey said. Apart from nuclear DNA analysis, the report found, “no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, draw a connection between evidence and a specific individual or source.”
So why are these techniques still used across the country? There’s no consistent federal accreditation system. There isn’t currently a uniform system of educating prosecutor’s offices on which methods are acceptable and which aren’t. The 2009 report recommended the creation of a federal agency to oversee and certify forensic sciences, but political will hasn’t swayed things in that direction, not to mention a lack of funding.