Bite Mark Evidence Authority Failure Through Unvalidated Pattern Matching Presented as Individualization in the Keith Allen Harward Case

In February 1982, a woman was raped and her husband was murdered in their apartment in Newport News, Virginia. The victim had bite marks on her body. Investigators obtained dental impressions from Keith Allen Harward, a sailor stationed at a nearby naval base, after the victim identified him from a photo lineup. Two forensic odontologists — specialists in the application of dentistry to legal proceedings — examined the bite marks and compared them to Harward's dental impressions. Both testified at trial that Harward's teeth matched the marks to the exclusion of other individuals.

Forensic odontology was recognized as a specialty within the American Academy of Forensic Sciences, with practitioners certified by the American Board of Forensic Odontology. ABFO-certified odontologists were routinely qualified by courts as expert witnesses. The discipline's foundational claim — that human dentition is sufficiently unique that a trained practitioner can identify a specific individual from a bite mark impression in skin — was accepted by courts based on the professional credentials of the witnesses and the discipline's acceptance within the forensic science community. This foundational claim had not been validated through controlled scientific testing.

Harward was convicted in 1982 and spent thirty-three years in prison. In 2016, DNA testing of biological evidence from the crime scene excluded Harward entirely and identified another individual — Jerry Crotty, who was already serving a life sentence for a similar crime committed in the same area shortly after the attack on Harward's victims. Harward was exonerated and released in April 2016, making his the longest wrongful incarceration overturned by DNA evidence in Virginia's history.

The exoneration demonstrated that the bite mark testimony that secured the conviction — the identification of Harward to the exclusion of other individuals — was wrong. The two credentialed forensic odontologists who examined the same marks and reached the same conclusion were both incorrect. The DNA evidence did not merely raise doubt; it affirmatively identified a different person as the source of the biological evidence, proving that the bite mark identification was a false positive — the discipline's methodology produced an incorrect individualization that withstood trial, appeal, and three decades of incarceration before an entirely different forensic method revealed the error.

The foundational premises of bite mark identification have never been scientifically validated. No peer-reviewed study has demonstrated that human dentition is unique enough to support individualization from bite mark impressions in skin. No study has demonstrated acceptable levels of inter-examiner reliability — that different qualified practitioners examining the same mark will consistently reach the same conclusion. The 2009 National Research Council report on forensic science identified bite mark analysis as lacking a demonstrated scientific foundation. The 2016 report by the President's Council of Advisors on Science and Technology concluded that bite mark analysis did not meet the scientific standards for foundational validity and was not appropriate for use in court.

The discipline continued to produce testimony that courts admitted because the pathway to courtroom admission evaluated the practitioner's credentials rather than the discipline's scientific foundation. An ABFO-certified forensic odontologist was qualified as an expert based on training, certification, and professional acceptance — the same criteria that would qualify an expert in a scientifically validated discipline. The court could not distinguish between a credential backed by validated science and a credential backed by professional consensus within a community that had never tested its own foundational claims. The expert looked the same. The certification looked the same. The testimony sounded the same. The science behind it was absent.

The Harward exoneration added to a growing body of DNA-confirmed wrongful convictions involving bite mark testimony — at least two dozen individuals have been exonerated or had charges dropped after bite mark evidence was discredited. The Texas Forensic Science Commission recommended a moratorium on bite mark evidence in criminal proceedings. Several courts have excluded or limited bite mark testimony. The ABFO has resisted calls for a moratorium, maintaining that the methodology is valid when properly applied, while acknowledging the need for further research. The discipline remains in contested status — still practiced, still admitted in some jurisdictions, still lacking the scientific validation that would establish that its foundational identification claim is true.