Tag Archives: forensic reform

Nothing to Smile About: Bite Mark Evidence Blasted Again

Your smile could cost you your freedom.

Just ask Crystal Weimer from Pennsylvania, or William Richards from California.  Weimer and Richards don’t know each other, but their fates were eerily and tragically similar.

Both were tried and convicted of murder in unrelated cases.  Both of their convictions were based on testimony by so-called bite mark experts, who claimed to have matched marks found on victims with each of the defendant’s “bite mark.”  In both cases, the prosecution relied heavily on the “matching” bite marks as proof of the defendants’ guilt.  In both cases, the bite mark evidence was just plain nonsense.

A new report released this week by the President’s Counsel of Advisors for Science and Technology (PCAST), offered yet another devastating critique of bite mark evidence:

available scientific evidence strongly suggests that [bite mark] examiners not only cannot identify the source of bite mark with reasonable accuracy, they cannot even consistently agree on whether an injury is a human bite mark. For these reasons, PCAST finds that bite mark analysis is far from meeting the scientific standards for foundational validity.

PCAST, an advisory group appointed by the President and made up of the nation’s leading scientists and engineers, suggested that bite mark analysis was unlikely to be “salvageable” as a forensic methodology and that scarce forensic resources should be devoted elsewhere.

The PCAST report adds to the chorus of experts that put bite mark evidence in the junk science category.  In 2009, leading scientists from the National Academy of Sciences issued a report condemning bite mark evidence as highly unreliable.

But despite all the criticism from top-notch forensic experts, bite mark evidence has not been banned from the court room.

Which means that innocent people could wind up in prison for crimes they didn’t commit based on “science” that isn’t scientific at all.

In June, 2016, both Weimer and Richards were exonerated – just one day a part.   As it turns out, the bitemark evidence that put them in prison was just plain wrong.  Collectively, they spent nearly thirty years in prison.

And that is nothing to smile about.





Friday’s Quick Clicks…

Four Years After Report Decrying Forensic Sciences, a Sign of Progress

Chemical & Engineering News has published an update of forensic science reform efforts entitled, “First Steps Toward Forensics Reform – New forensics commission to recommend guidelines, design policies.” The article provides a history of efforts taken thus far in response to the 2009 report by the National Research Council, which alerted the nation to many shortcomings in the reliability of the forensic sciences and their use in the courtroom.

According to the article (here) by Andrea Widener:

“Four years after the NRC report was released—and nearly as long as the White House has been studying it—the federal government has taken its first official steps to address the problem. The Department of Justice (DOJ) and the National Institute of Standards & Technology (NIST) have joined forces to create a National Commission on Forensic Science. That body will recommend guidelines for federal, state, and local forensics laboratories, as well as design policy on ethics, training, and certification for forensics professionals. Continue reading