Lawyers and some scientists question the validity of two DNA analysis techniques formerly used by New York City’s chief medical examiner. The result could affect thousands of criminal cases.
A coalition of defense lawyers is asking the New York State inspector general’s office to launch an inquiry into the use of disputed DNA analysis methods in thousands of criminal cases, the New York Times reports, with ProPublica. Over the past decade, the DNA laboratory of New York City’s chief medical examiner emerged as a pioneer in analyzing the most complicated evidence from crime scenes. It developed two techniques that went beyond standard practice at the FBI and other public labs for making identifications from DNA samples that were tiny or that contained a mix of more than one person’s genetic material.
As its reputation spread, the lab processed DNA evidence supplied not only by the New York police, but also by about 50 jurisdictions as far away as Bozeman, Mt., and Floresville, Tx., which paid the lab $1,100 per sample. Some scientists question the tests’ validity. In court testimony, an ex-lab official said she was fired for criticizing one method. A former member of the New York State Commission on Forensic Science said he had been wrong when he approved their use. The first expert witness allowed by a judge to examine the software source code behind one technique said its accuracy “should be seriously questioned.” This year, the lab shelved the two methods and replaced them with newer, more broadly used technology. The medical examiner’s chief of laboratories, Timothy Kupferschmid, said the discarded techniques were well-tested and valid, and that the lab adopted newer methods to align with changing FBI standards. He compared it to a vehicle upgrade. “So just because we’re switching to the new model, I mean, our old pickup truck worked great, but my new pickup truck is so much better,” he said.