For years, bite mark evidence has been seen as an unreliable science. It has led to at least four wrongful convictions overturned by DNA testing and processes of accreditation and peer review have been wildly inconsistent. One "expert" in the field, Dr. Michael West, claims that his method of examining bite marks — called the "West phenomenon" — can not be recreated by anyone else. Read more about West's involvement in a Mississippi death row case.
Now, a study at Marquette University in Milwaukee is aiming to reinforce bite mark evidence with scientific data and computer analysis.
Bite-mark patterns can vary wildly in clarity, and like a bruise, they can change over time. The quality of a bite mark also depends on the substance a person has bitten, as bite marks on gum or Styrofoam cups can be more defined than bite marks on skin. The force of the bite, the angle of the bite and the area bitten can all affect the appearance of a bite mark.
Forensic dentists apply their expertise to formulate an opinion on whether the accused could have made the particular bite mark patterns.
But the subjective nature of bite-mark analysis and interpretation has been the focus of harsh criticism, and forensic dentistry has been called a "junk science."
"False convictions leave bite marks with a black eye," said Donald Simley, a certified forensic dentist based in Madison. The study "should help the whole science of bite-mark evidence."
Read the full story
. (Milwaukee Journal Sentinel, 08/05/07)
Read more about how
bite mark evidence has contributed to wrongful convictions