April 20, 2015

Hair and Now

Whenever I hear tales about the failure of experts, I think of the 1986 Challenger disaster. Those were different days, and a full seventeen percent of the American public watched on TV as the Space Shuttle Challenger launched. Since Christa McAuliffe, a school-teacher, was one of the astronauts on board, young children all over the country were dragooned into classrooms to witness the blast-off. It was supposed to be a heart-warming, isn’t-America-great?, you-can-do-it lesson for the impressionable young tykes.

What could possibly go wrong? The engineering experts at NASA had assured everyone (and each other) about the safety of the shuttle program.

Well, an O-ring on the Challenger’s rocket booster failed, and millions of schoolchildren watched as their astronaut heroine got blown to smithereens. A whole generation grew up with a little dent in their childhood innocence. I hope some of them developed a healthy skepticism about the reliability of experts.CHALLENGER EXPLOSION

The subject crops up again in recent revelations that the FBI Laboratory in Quanitco, VA, consistently overstated the reliability of hair analysis. In case after case, the forensic techs at the FBI Lab’s Microscopic Hair Comparison Unit slanted their findings in ways that were scientifically challengeable or invalid. The Justice Department (aided by the Innocence Project and National Association of Criminal Defense Lawyers) analyzed 268 trials where hair analysis was used in evidence, and found flawed forensic testimony in an astonishing 95 percent of the cases. More sobering was the study included 32 death penalty trials.Screen Shot 2015-04-20 at 10.40.36 AM

So why was such flawed testimony used without question? Part of it, I think, is the infamous “CSI Effect,” named for the popular TV series. In forensic-based TV crime programs such as that one, it’s a black and white world. The evidence is always clear. Experts are never wrong. A single hair puts the bad guy away. CSI and other such entertainment is tremendously popular. So juries have become trained to believe expert testimony. It would be impossible to make up a jury in present-day America if jurists disqualified everyone in the pool who watched crime programs on TV.csi-gil-grissom

In the real world, it doesn’t work the way it happens on TV. The real world is not black and white, it’s herringbone. Evidence gets contaminated. Lab techs error. Investigatory bias creeps in.

Without a doubt, forensic science is an incredibly valuable tool. Bad people do bad things and should be brought to heel. But human fallibility has to be figured into both sides of the equation. Mistakes happen on both sides of the badge. When lives are at stake skepticism isn’t just healthy, it’s vital.