In Criminal Cases, Should Science Only Serve the State?

Forensic scientists who testify for criminal defendants are under fire. They ought to be praised.


Last month, the National Academy of Sciences (NAS) released a wide-ranging report expressing alarm at the way forensic science is used in the courtroom. Among the many problems the report addressed was the tendency of many states to see state-employed forensic experts not as independent scientists, but as part of the prosecution's "team."

The problem with that sort of arrangement is obvious: It introduces pressure—subtle or overt—on scientists to produce results that please police and prosecutors. The NAS report recommends that state-employed forensic experts be neutral. Today, far too many crime labs and medical examiners report to the attorney general of their states. Others report directly to the prosecutors in their jurisdictions. 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. In fact, it's almost universally accepted—among both prosecutors and medical examiners—that a government medical examiner should never testify against the district attorney who serves in the same jurisdiction, even if the medical examiner strongly disagrees with the prosecutor's conclusions. Lately, that already dubious notion seems to be expanding. Many law enforcement officials believe that government forensic experts should be barred from testifying for the defense in any case, even in other jurisdictions.

Earlier this month, the Minneapolis Star-Tribune reported that Minnesota District Attorney James Backstrom rebuked his county's medical examiner, Dr. Lindsey Thomas, because members of her staff had testified for defense attorneys in other counties, calling into question the conclusions of those counties' medical examiners. In one email to Thomas (you can read all of the emails here), Backstrom called the practice "a conflict of interest," and complained that the "added credibility attached to someone who is currently a coroner/medical examiner in another community who testifies as a defense expert makes any prosecution more difficult." In Backstrom's view, the actions of Thomas' staff were no different than if he were to testify that he disagreed with another prosecutor's strategy or conclusions. Backstrom ended one email by threatening to block Thomas's reappointment as the county's medical examiner if the practice continued.

Backstrom not only exhibited a fundamental ignorance of the purpose of forensic science in the courtroom, he also tellingly revealed a 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.

Sadly, Backstrom's view is all too common. 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.

Again, this is nonsense. We need more doctors willing to hold their rogue colleagues accountable, not less. For the last three years, I've been reporting on the severe inadequacies of Mississippi's criminal autopsy system. In particular, I've reported on Dr. Steven Hayne, who over the last 20 years has done 80 to 90 percent of the state's autopsies, carrying an impossible workload of some 1,500 to 1,800 autopsies per year (by his own account), despite the fact that he isn't board-certified in forensic pathology. Hayne's colleagues have known for years that he's little more than a rubber stamp for prosecutors. He has inflicted incalculable damage on the state's criminal justice system.

Kris Sperry, along with several current and former state medical examiners in Alabama, is one of the few doctors who has been trying to hold Hayne accountable. Over the years, Sperry has written letters to professional organizations asking for Hayne to be investigated. Yes, he has also testified against Hayne and other disreputable Mississippi medical examiners in court. He ought to be lauded for that, not condemned.

The other problem here, as the NAS study points out, is that there is currently a critical shortage of board-certified medical examiners. If every forensic pathologist with a government job or contract were barred from ever testifying for criminal defendants, there wouldn't be many doctors left to testify. The few who were left couldn't possibly testify in every case where they're needed—and in those cases they do take, they could easily be impeached by prosecutors as guns-for-hire.

But then, maybe that's the point.

You'd think that a forensic expert who tells the jury that he testifies for both defense attorneys and prosecutors would carry more weight on those occasions when he testifies for the state. That would show a doctor who testimony follows the science. But for prosecutors like Backstrom, the primary concern is not embarrassing his fellow district attorneys, and ensuring that credible doctors with state credentials don't screw up another prosecutor's case—even if that case is based on faulty science.

It takes an odd definition of justice to believe that state-paid scientists should only use their expertise to help win prosecutions. Unfortunately, that view seems to be the prevailing one.

Radley Balko is a senior editor at Reason magazine.