Congress Probes Science Behind Convictions A recent study questions the scientific validity of many forensic techniques routinely used in criminal prosecutions. Lawmakers at a Senate hearing on Wednesday asked whether people have been put to death for crimes they didn't commit based on these techniques.
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Congress Probes Science Behind Convictions

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Congress Probes Science Behind Convictions


Congress Probes Science Behind Convictions

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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Thousands of people have gone to prison based on forensic evidence such as fingerprint analysis or hair samples. A recent report by the National Academy of Sciences said many of those forensic techniques have never been scientifically tested.

Well, today a Senate panel tried to figure out what Congress should do about it. NPR's Ari Shapiro attended the hearing. He has this report.

ARI SHAPIRO: Case Western Reserve professor Paul Giannelli told the Senate Judiciary Committee, this report on forensics...

Professor PAUL GIANNELLI (School of Law, Case Western Reserve University): SHAPIRO: The report concluded that DNA analysis is the only forensic technique that has been scientifically proven to connect crime scene evidence to a defendant. Everything else, from ballistics to blood splatters, is uncertain.

Committee chairman Patrick Leahy said it's unacceptable to send people to prison, or to death, based on forensic evidence that has never been scientifically validated.

Senator PATRICK LEAHY (Democrat, Vermont): Our criminal justice system, particularly the most serious cases, have to be based on facts.

SHAPIRO: The report also said there are no national standards for the people doing forensic analysis. For example, one fingerprint analyst may declare a match if he can identify six points in common between a crime scene print and a defendant. Another analyst might require 14 common points to declare a fingerprint match.

The committee's top Republican, Jeff Sessions of Alabama, found these conclusions difficult to swallow.

Senator JEFF SESSIONS (Republican, Alabama): I don't think we should suggest that those proven scientific principles that we've been using for decades are somehow uncertain.

SHAPIRO: But many forensic principles are neither proven nor scientific, according to this report. Congress commissioned the study and the nonpartisan National Academy of Sciences wrote it after two years of research.

Peter Neufeld directs the Innocence Project. He introduced Roy Brown, who sat in the audience of the hearing room. Neufeld said Brown was convicted of murder based largely on testimony from a forensic dentist.

Mr. PETER NEUFELD (The Innocence Project): The forensic dentist used what was then the prevailing methods of comparing bite marks found on a body with the dentures of a suspect, and he examined them and decided that he had a match with Roy's bite. He so testified in court, and Roy was convicted.

SHAPIRO: After Roy Brown spent 15 years in prison, DNA evidence identified the real killer. Neufeld said bite mark analysis is just one of many areas that remain untested.

Mr. NEUFELD: And they need more research, basic research, applied research. They need standards like DNA has.

SHAPIRO: Prosecutors at the hearing said defense lawyers are already using the forensics report to challenge convictions.

Mr. BARRY MATSON (Chief Prosecutor, Alabama Computer Forensic Laboratories): This is true even though the report made efforts to say that no judgment is made about past convictions and no view is expressed as to whether courts should reassess the cases that've already been tried.

SHAPIRO: Barry Matson is a prosecutor in Alabama.

Mr. MATSON: Have regrettable instances occurred in the forensic setting? Yes. Is it to the level that some entities and special projects would have us to believe? Absolutely not. As long as human beings are involved, we will endeavor to do the very best we can, but no system we ever have will be perfect.

SHAPIRO: Everyone seemed to agree that more research is a good thing. There also seemed to be consensus that there should be national standards for crime labs and for analysts, because, as everyone at the hearing said, it is in no-one's interest for innocent people to be locked up or guilty people to go free. Ari Shapiro, NPR News, Washington.

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