Junk Science Review: Texas to Examine Microscopic Hair Analysis in Criminal Convictions
Less than a year since the U.S. Department of Justice announced it would review the "highly unreliable" results of microscopic hair analysis in federal cases, the State Forensic Science Commission will do the same in Texas. In cases nationally where DNA has later exonerated the wrongfully imprisoned, microscopic hair analysis turned up like a bad penny in nearly a quarter of them, usually to buttress other evidence, like faulty eyewitness testimony.
A study by the National Academy of Sciences found that it could exclude suspects, but could not single them out with any reliability. With the advent of mitochondrial DNA testing in the mid-1990s, prosecutors rely on this kind of testimony less and less nowadays. The review will center on older cases where microscopic hair analysts -- many of whom were trained by the FBI -- contributed to a conviction.
"Of course," the commission says in its report, "this does not necessarily mean that state and local analysts in Texas made similar overstatements. It is also unclear whether the FBI actually trained analysts using principles that could overstate a positive association, or whether the analysts who received FBI training followed the FBI's lead in their own testimony."
Nevertheless, better safe than sorry. The Innocence Project of Texas is already poring through a list of potential clients whose cases involve hair microscopy. And Southwest Institute of Forensic Sciences in Dallas, one of the state's major crime labs, has supplied a list of cases for review.
What this may all add up to is another series of challenges to convictions based on junk science. A law that went into effect last year, authored by Senator John Whitmire, provides an automatic avenue for Texans to challenge their convictions if they're based on evidence that doesn't withstand present-day scrutiny. We detailed just such a case in a recent cover story. Sonia Cacy was convicted on arson testimony that has been deemed unsupportable by a number of experts and the State Fire Marshal's Office.
Texas can be backward in a lot of ways, but we're at the bleeding edge in terms of forensic science and its implications for the criminal justice system.