How Bitemark evidence is still operating at the appellate level – The Kunco Case

The “relatively unique teeth” of John Kunco

The “recaptured” evidence used against Kunco.

There still is a long road for prison inmates to overcome what now is considered to be unvalidated “science” presented at their original trials. John Kunco’s case is a standout and is still being litigated by the NY Innocence Project. Some of the bitemark fellows are having problems with their past cases which mimic the IP’s case list of successful conviction reversals and full exonerations involving bitemark opinions. Such as Steven Chaney’s in Texas.

A two article blog post by David Averill about Kunco and the ongoing  bitemark “war” is available here. It contains numerous evidence photos and further case info. The  “excerpts” give you the gist of what some have called “voodoo science” (Wall St Journal, yesterday). Its second section is what the judge said during Kunco’s previous appeal.

Bitemark Evidence in the Kunco Case


May 15, 2011

by Dr. David Averill

The bitemark evidence in the Kunco case consisted of a photograph showing a bitemark on the shoulder of the victim. The bitemark evidence became case critical when the 40 pieces of physical forensic evidence recovered at the scene, which included hair, blood and fiber did not link to the suspect John Kunco. The authorities then consulted a board certified ABFO forensic dentist five months after the crime.

The consulting forensic dentist explained that a scale in the photograph is necessary for the bitemark comparison process. The forensic dentist recalled hearing about a technique that Dr. Michael West developed using UV photography to penetrate the skin in order to capture bruising that still exists below the skin. He believed that he might be able to “see” the old bitemark now not visible through the use of UV photography. The forensic dentist consulted a colleague and photographed the area on the shoulder with UV light. It is from this photograph 5 months after the bite to the shoulder that the intricate details of the biter’s teeth are described through “skin reading”.

Dr. Sobel’s testimony

I could say that within a reasonable dental certainty, that the bite on the left back shoulder area of Donna Seaman was in fact inflicted by the teeth of John Kunco.

I felt comfortable about this decision because there were no inconsistencies that I could come up with at all and everything fit perfectly.

Now, all teeth in a bite do not always follow exactly the same size relationships, because remember, we’re biting into an elastic surface. It’s the pattern that we’re looking at.

There is no doubt in my mind.

The size relationships, the shape of the teeth … the fractured portions of a tooth, the worn areas, all of these taken together create a fingerprint picture of the individual.

Dental identification next to fingerprints is the most accurate form of identification of an individual.

I then did an acetate overlay in which I traced some of the outlines of these teeth onto the acetate (exhibit 21).

Tooth number 8 tapers upward, there’s a difference in the plane of the surface. Thus there wasn’t any mark visible because it appeared that the head was tilted to the left angle making the bite only a partial bite involving basically the left side of the mouth, upper and lower.

First of all, the plane of the teeth, you can see how this tooth is lower than the others, and any bite would then leave off that particular area. Especially if the head were tilted in this way.

Exhibit 22 – I prepared this overlay to investigate the pattern of the mark. In other words, to see what we could isolate in the way of teeth and uniqueness of individual characteristics and the class characteristics.

I randomly selected approximately 30 sets of models and compared them to the same imprints to see if there were any consistencies that could come up in other individuals easily, although we can duplicate some curvatures of the arch, we could not duplicate all of the individual characteristics.

I felt secure in seeing everything matched perfectly as a group and individually; all the features were consistent.

Dr. David’s testimony

Kunco had a relatively unique set of teeth.

Remarkable consistency between Kunco’s bite pattern and the bite mark on the victims shoulder.

The teeth of the defendant, John Kunco, made the bite mark.

Not only is it consistent, but also it is a remarkable consistency.

There were some inconsistencies in the tracing, which are explained by the dynamics of the bite.

I did not include in the report, an explanation how I did my analysis… its not typically placed in a report.

Court Denies Kunco Relief in “Recaptured Bite Mark” Case
April 22, 2011
By Dr. David Averill

The court has recently denied relief, due to legal technicalities in the 1991 Kunco v. Commonwealth of Pennsylvania case where perhaps one of the most egregious uses of bitemark evidence was used to convict a man to 45-90 years in prison. Radley Balko, a Senior Editor of Reason Magazine first wrote about this case in 2009, which he published on his web site at

The case involves the brutal rape and torture of a 55-year-old woman. Two ABFO board certified forensic dentists became involved in the case 5 months after the crime. They were hired to analyze a bitemark on the shoulder of the victim. This request came only after more than 40 pieces of forensic evidence collected at the crime scene, which included hair; blood and fiber did not link to the police’s suspect.

The police had photographed the bitemark at the time of the crime but failed to include a scale in the photograph as a reference, which is required to compare the bitemark to a suspect’s dentition. To rectify this situation the ABFO experts resorted to a novel photographic technique that they had learned from Dr. Michael West, which they claimed to show the bitemark, despite the 5 months of healing which had taken place.

The Innocence Project first took this case on in 1993 and appealed on the basis of the novel UV photographic technique the experts used to “recapture” the bitemark 5 months later. The experts learned the technique from former ABFO member and now dis-credited forensic analyst, Dr. Michael West (see previous post). The Innocence Project used Dr. Gregory Golden as the forensic dental photography expert who testified that the UV reflectance photographic technique was unreliable. He was opposed in court by Dr. Robert Barsley who the court felt satisfactorily rebutted Dr. Golden’s testimony since some sort of marks could be seen in the UV reflectance “recaptured photograph” purported to be a bitemark. There was no discussion at the time surrounding the ability of this bitemark without details to be used to identify a specific individual. Historically this was at a time when bitemarks were being used and accepted in the courts across the country with an irrational exuberance. It was only later as DNA that has been recovered from many of these overstated and unsupported opinion bitemark cases that the reliability and validity of bitemarks have come under intense scrutiny and question by the media.

The end result of this bogus bitemark court case was the closing arguments by the prosecutor using the bitemark evidence as the nail in the coffin for the defendant proving his guilt:

[T]here’s no way, no way on this earth, for Mr. Kunco to explain how his tooth marks got on Donna Seaman’s shoulder unless you accept the fact that he’s the one who attacked and brutalized Mrs. Seaman. That’s the only explanation, ladies and gentlemen. That’s why the evidence is better than fingerprints or hair samples … [T]he bite mark on Danna Seaman’s shoulder was as good as a fingerprint. And I submit to you it was that, ladies and gentlemen, for all intents and purposes. Ladies and gentlemen, I’d submit to you that John Kunco should have just signed his name on Donna Seaman’s back, because the bite mark on Donna Seaman’s shoulder belongs to John Kunco.





About csidds

Dr. Michael Bowers is a long time forensic consultant in the US and international court systems.
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1 Response to How Bitemark evidence is still operating at the appellate level – The Kunco Case

  1. csidds says:

    Reblogged this on FORENSICS and LAW in FOCUS @ CSIDDS | News and Trends and commented:

    Read the trial testimony of the bitemark expert in this 1991 murder trial. He talks “about consistencies” which later became an “identification.”

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