Ray Krone is skeptical of new technology that promises to lend credence to bite marks as evidence in court cases.
The Conewago Township resident has reason to be suspicious: In 1992, he was found guilty of killing a Phoenix bartender based largely on expert testimony that his teeth matched bites on the victim. In fact, he was nicknamed "the Snaggletooth Killer" because of his ragged teeth.
Police first had Krone bite into a piece of Styrofoam, then later took a cast of his teeth. Krone was convicted twice, once by a judge and once by a jury.
But in 2002, Krone's lawyers said a DNA test matched another man listed in the FBI's database. A police lab confirmed the match and, later that year, Krone was released from prison.
For a decade, attorneys and some forensic experts have ridiculed the use of bite marks to identify criminals as sham science and glorified guesswork. It has sent innocent men such as Krone to death row, given defense attorneys fits and splintered the scientific community.
Now researchers at Marquette University say they have developed a first-of-its-kind computer program that can measure bite characteristics. They say their work could lead to a database that could narrow down suspects and lend more scientific weight to bite-mark testimony.
But Krone, 51, questions the validity of bite marks, saying they do not possess the same unique qualities that DNA or fingerprints do.
"There's too many people out there that have teeth that are similar," he said.
He added that skin, where bite marks are usually found, is "a very poor medium" for getting a clear picture.
His concerns echo those of some forensic scientists.
"The naysayers are saying, 'You can throw all this out. It's junk science,'" said team leader Dr. L. Thomas Johnson, a forensic dentist who helped identify victims of cannibalistic serial killer Jeffrey Dahmer. "It's a valid science if it's done properly."
Built around the assumption that every person's teeth are unique, forensic dentistry has used bite impressions to identify criminals for 40 years.
But critics say human skin changes and distorts imprints until they are nearly unrecognizable. As a result, courtroom experts end up offering competing opinions.
Determined to prove that bite analysis can be done scientifically, Johnson and his team collected 419 bite impressions from Wisconsin soldier volunteers.
They built a computer program to catalog characteristics, including tooth widths, missing teeth and spaces between teeth. The program then calculated how frequently each characteristic appeared.
Johnson hopes to collect more impressions from dental schools across the country to expand the database. With enough samples, the software could help forensic dentists answer questions in court about how rarely a dental characteristic appears in the American population. That would help exclude or include defendants as perpetrators, Johnson said.
He acknowledged that his software will probably never turn bite-mark analysis into a surefire identifier like DNA and that he would need tens of thousands of samples before his work would stand up in court.
But "this is the first step toward actually providing science for this type of pattern analysis," Johnson said.
Krone, who underwent major dental surgery thanks to ABC's TV show "Extreme Makeover" several years ago, is now director of training and communication for Witness to Innocence, a nonprofit that supports death-row exonerees.
Staff writer Ted Czech and The Associated Press contributed to this report.
Since 2000, at least seven people in five states who were convicted largely on bite-mark identification have been exonerated, according to the Innocence Project, which works to free wrongfully convicted inmates.
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