At least 24 men convicted or charged with murder or rape based on bite marks on the flesh of victims have been exonerated since 2000, many after spending more than a decade in prison. Now a judge’s ruling later this month in New York could help end the practice for good.
A small, mostly ungoverned group of dentists carry out bite mark analysis and their findings are often key evidence in prosecutions, even though there is no scientific proof that teeth can be matched definitively to a bite into human skin.
DNA has outstripped the usefulness of bite mark analysis in many cases: The FBI doesn’t use it and the American Dental Association does not recognize it.
“Bite mark evidence is the poster child of unreliable forensic science,” said Chris Fabricant, director of strategic litigation at the New York-based Innocence Project, which helps wrongfully convicted inmates win freedom through DNA testing.
Supporters of the method, which involves comparing the teeth of possible suspects to bite mark patterns on victims, argue it has helped convict child murderers and other notorious criminals, including serial killer Ted Bundy.
They say problems that have arisen are not about the method, but about the qualifications of those testifying, who can earn as much as $5,000 a case.
“The problem lies in the analyst or the bias,” said Dr. Frank Wright, a forensic dentist in Cincinnati. “So if the analyst is … not properly trained or introduces bias into their exam, sure, it’s going to be polluted, just like any other scientific investigation. It doesn’t mean bite mark evidence is bad.”
The Associated Press reviewed decades of court records, archives, news reports and filings by the Innocence Project in order to compile the most comprehensive count to date of those exonerated after being convicted or charged based on bite mark evidence. Two dozen forensic scientists and other experts were interviewed, including some who had never before spoken to a reporter about their work.
The AP analysis found that at least two dozen men had been exonerated since 2000, mostly as a result of DNA testing. Many had spent years in prison, including on death row, and one man was behind bars for more than 23 years. The count included at least six men arrested on bite mark evidence who were freed as they awaited trial.
Two court cases this month are helping to bring the debate over the issue to a head. One involves a 63-year-old California man who is serving a life term for killing his wife, even though the forensic dentist who testified against him has reversed his opinion.
In the second, a New York City judge overseeing a murder case is expected to decide whether bite mark analysis can be admitted as evidence, a ruling critics say could kick it out of courtrooms for good.
Some notable cases of faulty bite mark analysis include:
• Two men convicted of raping and killing two 3-year-old girls in separate Mississippi crimes in 1992 and 1995. Marks on their bodies were later determined to have come from crawfish and insects.
• A New Mexico man imprisoned in the 1989 rape and murder of his stepdaughter, who was found with a possible bite mark on her neck and sperm on her body. It was later determined that the stepfather had a medical condition that prevented him from producing sperm.
• Ray Krone, the so-called “Snaggletooth Killer,” who was convicted in 1992 and again in 1996 after winning a new trial in the murder of a Phoenix bartender found naked and stabbed in the men’s restroom of the bar where she worked. Krone spent 10 years in prison, three on death row.
Raymond Rawson, a Las Vegas forensic dentist, testified at both trials that bite marks on the bartender could only have come from Krone, evidence that proved critical in convicting him.
At his second trial, three top forensic dentists testified for the defense that Krone couldn’t have made the bite mark, but the jury didn’t give their findings much weight and again found him guilty.
In 2002, DNA testing matched a different man, and Krone was released.
Rawson, like a handful of other forensic dentists implicated in faulty testimony connected to high-profile exonerations, remains on the American Board of Forensic Odontology, the only entity that certifies and oversees bite mark analysts. Now retired, he didn’t return messages left at a number listed for him in Las Vegas.
Rawson has never publicly acknowledged making a mistake, nor has he apologized to Krone, who described sitting helplessly in court listening to the dentist identify him as the killer.
“You’re dumbfounded,” Krone said in a telephone interview from his home in Newport, Tenn. “There’s one person that knows for sure and that was me. And he’s so pompously, so arrogantly and so confidently stating that, beyond a shadow of doubt, he’s positive it was my teeth. It was so ridiculous.”
The history of bite mark analysis began in 1954 with a piece of cheese in small-town Texas. A dentist testified that a bite mark in the cheese, left behind in a grocery store that had been robbed, matched the teeth of a drunken man found with 13 stolen silver dollars. The man was convicted.
The first court case involving a bite mark on a person didn’t come until two decades later, in 1974, also in Texas. Two dentists testified that a man’s teeth matched a bite mark on a murder victim. Although the defense attorney fought the admissibility of the evidence, a court ruled that it should be allowed because it had been used in 1954.
Bite mark analysis hit the big time at Bundy’s 1979 Florida trial.
On the night Bundy went on a killing spree that left two young women dead and three others seriously wounded, he savagely bit one of the murder victims, Lisa Levy. A Florida forensic dentist, Dr. Richard Souviron, testified at Bundy’s murder trial that his unusual, mangled teeth were a match.
Bundy was found guilty and executed. The bite marks were considered the key piece of physical evidence against him.
That nationally televised case and dozens more in the 1980s and 1990s made bite mark evidence look like infallible, cutting-edge science, and courtrooms accepted it with little debate.
Then came DNA testing. Beginning in the early 2000s, new evidence set free men serving prison time or awaiting the death penalty largely because of bite mark testimony that later proved faulty.
At the core of critics’ arguments is that science hasn’t shown it’s possible to match a bite mark to a single person’s teeth or even that human skin can accurately record a bite mark.
Fabricant, of the Innocence Project, said what’s most troubling about bite mark evidence is how powerful it can be for jurors.
“It’s very inflammatory,” he said. “What could be more grotesque than biting someone amid a murder or a rape hard enough to leave an injury? It’s highly prejudicial, and its probative value is completely unknown.”