Lawyers say skepticism around bite-mark analysis warrants exoneration or retrial
Increasing scientific skepticism of bite-mark analysis, including a shift within the organization that accredits dentists to testify about bite marks in court, warrants a new trial for an Allegheny County man convicted of raping and torturing a New Kensington woman 25 years ago, his lawyers argued Monday.
John Kunco, 51, formerly of Harrison, had been convicted in 1991 based in part on a partially healed bite mark. Two forensic dentists said it matched his distinctive set of teeth. He is serving a 90-year sentence at the State Correctional Institution in Fayette County, and his previous appeal for post-conviction relief was denied in 2009.
But attorneys for the New York-based Innocence Project argued Monday that more scientific organizations questioning the validity of bite-mark analysis, including the American Board of Forensic Odontologists, meant that Westmoreland County Common Pleas Judge Christopher Feliciani should exonerate Kunco or grant him a new trial.
“Knowing now what we did not know then, that bite mark could not be attributed to Mr. Kunco,” said defense attorney Karen Thompson.
The American Board of Forensic Odontologists, which certifies dentists as experts in identifying remains based on teeth, analyzing bite marks and comparing them to potential suspects' teeth, changed its guidelines in March to say that its members could no longer conclude a bite mark came from a certain individual or probably came from that person. Dentists could only say whether or not they could exclude a suspect, if they could make any conclusion at all.
“Staying within the guidelines, my opinion would have to be different,” said dentist Thomas David of Marietta, Ga., one of two dentists who testified at the trial that Kunco had bitten the 55-year-old victim.
“I can conclude whatever I want, but to stay within the guidelines, I can only say, ‘He can't be excluded,' ” David said. “I was confident in my opinions at the time, but it was up to the jury to decide. ... I don't know how much weight the jury gave it.”
Dentists who ignore the board's guidelines and continue to make individual identifications of bite marks could be subject to ethics complaints, he said.
The board's change on bite-mark analysis had to overcome years of resistance and a change in leadership toward more skeptical members, board member Cynthia Brzozowski said .
“I viewed my participation (in Monday's hearing) as my ethical duty,” Brzozowski said. “I'd become discouraged with each wrongful conviction that went unaddressed, with each study that was dismissed.”
An internal study of 100 pictures of marks conducted by current board President Adam Freeman found many of its accredited dentists couldn't even agree on whether all the marks pictured were human bites, indicating uncertainty and subjectivity in the analysts' very first steps, Freeman said. He called the board's change of guidelines a “quantum leap” in its attitude.
Other scientific organizations were increasingly skeptical of bite-mark analysis based on similar concerns, including the President's Council of Advisors on Science and Technology in a September report, and the Texas Forensic Science Commission, which ordered a moratorium on using bite-mark analysis in Texas prosecutions in February.
Such reports have questioned whether human skin could capture an accurate impression of the biter's teeth given its elasticity, swelling and healing; whether people's teeth were unique enough to match a mark to one person alone; and whether the conclusions dentists reached were objective enough to be valid.
Assistant District Attorney James R. Hopson argued that the change in scientists' attitudes didn't count as “new facts or evidence” to warrant a new trial. He said Kunco's defense could have found its own experts to rebut the prosecution witnesses during the original trial, but Kunco waived that right rather than delay things further.
The victim in the case died in 2012, which Hopson said would prejudice the jury against the prosecution in a retrial. Other evidence, including the victim's testimony about her attacker's distinctive lisp, supported Kunco's conviction, Hopson said.
Both sides will have 30 days to submit written briefs to the court, and Feliciani said he would make his decision as soon as possible.
Matthew Santoni is a Tribune-Review staff writer. Reach him at 724-836-6660 or email@example.com.