The scientific rigor of entrenched forensic disciplines has been challenged for years. Still, we live in a “C.S.I.” world, and television viewers could be forgiven for assuming that laboratory techniques used to catch bad guys are unassailable. In real life, though, the soundness of criminal analysis is being regularly tested, both in America’s labs and in its courtrooms.
It was long accepted as a virtually unerring technique to prove that this suspect — without a doubt, Your Honor — was the criminal. Wasn’t a hair found at the scene?
But with the advent of DNA analysis in the late 1980s, apparent matches of hair samples ultimately proved to be not quite as flawless as people had been led to believe. Instances of wrongful imprisonment make that clear.
Other lab techniques have had their reliability in the courtroom called into question. A 2009 report by a committee of the National Academy of Sciences found “serious problems” with an assortment of methods routinely relied on by prosecutors and the police. They included fingerprinting, blood typing, weapons identification, shoe print comparisons, handwriting, bite marks and — yes — hair testing. DNA was the game changer. The 2009 report said that, with the exception of nuclear DNA analysis, “no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source.”
Source: The New York Times, Clyde Haberman, May 18, 2014
