Forensic scientists who testify for criminal defendants are under fire. Radley Balko says they ought to be praised:
Ideally, government medical examiners would not only be independent of the state’s law enforcement agencies, they would be free to testify against any state claims unsupported by scientific evidence. But that isn’t the case in most of the country…
Last week, the local Fox affiliate in Atlanta ran two investigative pieces critical of Georgia’s chief state medical examiner, Dr. Kris Sperry. The station’s big scoop was that Sperry—who has an impeccable reputation among his peers—was regularly testifying for criminal defendants in other jurisdictions. The report quoted a sheriff and former county coroner in Harrison County, Mississippi, both still angry at Sperry for contradicting the state medical examiner’s testimony in a murder case. The piece included quotes from both Mississippi officials stating that a medical examiner who gets a government paycheck should never contradict another government medical examiner in court. One Tennessee official said the practice was akin to a police officer testifying against another police officer.
On the striking philosophical difference between the fields of science and law enforcement:
Law enforcement officers—be they police officers or prosecutors—assume a sort of fraternity that precludes them from criticizing one another. Cops almost never testify against other cops—even when a fellow officer has broken the law—and prosecutors rarely criticize other prosecutors. Scientists, on the other hand, are not only willing to criticizing other scientists, but the process of peer review—a fundamental component of the scientific method—actually depends on such criticism. Backstrom’s efforts to undermine peer review are alarming, particularly given that his efforts are aimed at the courtroom, where so much is frequently at stake.
His story is backed up be a National Academy of Sciences report, Strengthening Forensic Science in the United States: A Path Forward (2009), expressing alarm at the way forensic science is used in the courtroom. Here’s more on the Georgia state medical examiner story.