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Researchers Hope To Take A Bite Out Of Crime

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By TODD RICHMOND

The Associated Press

Published: May 24, 2008

MILWAUKEE - It has sent innocent men to death row, given defense attorneys fits and splintered the scientific community.

For a decade now, lawyers and even some forensic experts have ridiculed the use of bite marks to identify criminals as sham science and glorified guesswork.

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 of bite characteristics that could narrow down suspects and lend more scientific weight to bite-mark testimony.

"The naysayers are saying, 'You can throw all this out. It's junk science. It's voodoo. This is a bunch of boobs that are causing a lot of problems and heartaches for people,'" said team leader L. Thomas Johnson, a forensic dentist who helped identify victims of the cannibalistic Milwaukee serial killer Jeffrey Dahmer. "It's a valid science if it's done properly."

Skeptics already are taking shots.

"Scientifically illiterate," Mike Bowers, a deputy medical examiner in Ventura County, Calif., and a member of the American Board of Forensic Odontology, said of Johnson's work.

Built around the assumption that every person's teeth are unique, forensic dentistry has used bite impressions to identify criminals for 40 years. Bite marks on a young woman helped convict serial killer Ted Bundy of murdering her and another college student.

But critics say human skin changes and distorts imprints until they are nearly unrecognizable. As a result, courtroom experts end up offering competing opinions.

"If the discipline lends itself to opposing experts, it's not science," said Peter Neufeld, co-director of the Innocence Project, which works to free wrongfully convicted inmates.

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.

In Arizona, Ray Krone was found guilty in 1992 of killing a Phoenix bartender based largely on expert testimony that his teeth matched bites on the victim. He was sentenced to death, won a new trial on procedural grounds, was convicted again and got life. But DNA testing in 2002 proved he wasn't the killer. Krone was freed.

In Mississippi, forensic odontologist Dr. Michael West has come under fire after he testified in two child rape-murders in the 1990s that bite marks positively identified each killer. Kennedy Brewer was sentenced to death in one case, and Levon Brooks got life in prison in the other.

DNA tests later connected a third man to one of the rapes, and investigators say he confessed to both murders. In Brewer's case, a panel of experts concluded that the bites on the victim probably came from insects. Brewer and Brooks were exonerated earlier this year.

Determined to prove that bite analysis can be done scientifically, Johnson and his team won about $110,000 in grants from the Midwest Forensic Resources Center at Iowa State University and collected 419 bite impressions from Wisconsin soldier volunteers.

They built a computer program to catalog characteristics, including teeth widths, missing teeth and spaces between teeth. The program then calculated how frequently - or infrequently - each characteristic appeared.

He hopes to collect more impressions from dental schools across the country to expand the database into something close to law enforcement's DNA databanks. 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.

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