This is part two in a four-part series. Read part one here.
On May 4, 1692, the Rev. George Burroughs was arrested in Salem, Massachusetts on suspicion of witchcraft. The only physical evidence against Burroughs were bite marks found on some of the girls he was accused of recruiting to join him. Summarizing the research of historians on the ordeal in an article for the February 2014 newsletter of the New York State Dental Association, William James Maloney writes that at trial, “the defendant’s mouth was pried open and the prosecution compared his teeth with the teeth marks left on the bodies of several injured girls present in the courtroom.”
At the urging of notorious witch hunter Cotton Mather, Burroughs was convicted, sentenced to death and hanged. Two months later, the governor of Massachusetts called for an end to the witchcraft trials. He also prohibited the use of “spectral and intangible evidence” in criminal trials. Two decades later, Burroughs was declared innocent, and the colony of Massachusetts compensated his children for their father’s wrongful execution.
Nearly three hundred years later, in 1974, Walter Edgar Marx was convicted of voluntary manslaughter due in part to bite marks found on the nose of his alleged victim. The marks were found during an exhumation of the victim’s body more than six weeks after she had been autopsied, embalmed and buried. Three dentists testified for the state that they could match an impression made of the marks to Marx’s teeth. In 1975, a California appeals court upheld the conviction. That ruling has become enormously influential. In a 2000 article for the Albany Law Review, Seton Hall law professor and evidence expert Michael Risinger wrote that the Marx ruling “came to be read as a global warrant” for courts to admit bite mark evidence.
The Marx case effectively went around the prevailing standard for admitting forensic evidence: the 1923 case Frye v. United States, in which the U.S. Court of Appeals for the D.C. Circuit rejected testimony from a polygraph instructor who claimed that a rise in systolic blood pressure indicated that a suspect was lying. The appeals court ruled that in order to be admissible in federal court, scientific evidence or testimony must have “gained general acceptance in the particular field in which it belongs.” For the next 70 years, Frye was the model in federal court, and was subsequently adopted by nearly every state in the country. (The Supreme Court didn’t address the standard until 1993, with three rulings now known as the Daubert cases. The Daubert standard instructs judges to assess both the relevance of expert testimony and whether the testimony itself is reliable.)