FORENSICS and LAW in FOCUS @ CSIDDS | News and Trends

Today’s subject is a brief look back at how pattern evidence from bruised human skin got into the case law of every state in the US. Its not a pretty process, as I describe below.

Scientists learn from their past studies which includes unsuccessful experimentation. The recognition and use old data to construct new theories and experimental hypotheses is part of  scientific progress. But scientific tenets don’t seem to apply to dentists who deal in bitemark IDs. They  liken themselves as still being relevant for courts. One caveat: these days they disappear when DNA is available

Assumptions of personal rather than fact of empirically proven nature were and still are acceptable by judges and rules of evidence. One past AAFS/ABFO president (among other forensic types) said, after the 2009 NAS Report on bitemarks laid out all its “scientific” mumbo-jumbo”, that hard scientific proofs (meaning testing that allows repeatability among numerous research agencies) are unattainable in forensics regarding this type of evidence. Carrying such logic further, this implies courts should still rely on expert testimony founded on opinions of “reasonable certainty.”  I think he forgot how this lawyer-developed certainty of opinion has led to dozens of innocent defendants ending up in prison. Hundreds of bitemark cases from past decades seem cloaked in some “cone of silence” protection created by both the AAFS and its underling bitemark-board, the ABFO.  At this point, all we have are the cases summaries from judicial literature.

Here is one case.

The dentists mentioned in the following 1980 appellate acceptance of the bitemark craft were lauded as “crime fighters.” Their progeny of today wish for a return to glory.

I will just highlight the “reasonable certainty”statements in this often-cited case of expert statements which never have been scientifically proven.  A few comment will be included.

State v. Sager, 600 SW 2d 541 – Mo: Court of Appeals, Western Dist. 1980

“Dr. Luntz concluded that the bite mark reflected in the photograph of the breast of the victim was beyond a reasonable doubt placed upon the victim’s breast by appellant.”

A typical “I see it, therefore it is” statement.

“Dr. Furness testified he had viewed approximately 150 bite mark cases and that if one dissimilarity appeared, this would exclude the person as a suspect.”

“Dissimilarities” between any purported bite evidence and a suspect are now allowed to be dismissed by merely saying “this is caused by dynamic biting force and pressure. (California v. Eric Frimpong. 2008.)  Defendant was convicted. 

“He further stated that although it might appear to the layman that bite marks appear similar, it is impossible for two humans to make exactly the same bite mark.”

Classic statement that has yet to be proven. It hints to the following “leap of faith.”

“He explained his analysis depicted in the visual aids used as exhibits explaining how the teeth corresponded to the bite marks, describing the reasons for assigning each of the points of similarity. The points of similarity were assigned on the basis of corresponding positions, high spots, spacing irregularities and outer surfaces of the teeth.”

This analogy to fingerprint  comparisons has been used over the decades by bitemark dentists for its powerful effect. It rapidly falls apart, as there has never been a successful study or series of studies on the subject. An attempt in 1986 by the ABFO ultimately was rejected due to lack of repeatability amongst its members. 

“He denied that embalming a body would distort a bite mark.”

Never been tested. Forensic pathologists would find this an amazing statement. Used numerous times in many precedent setting bitemark cases. 

“He concluded that in his opinion, “based upon reasonable medical and dental certainty” that the person from whom the casts were obtained inflicted the wound depicted in the colored photograph. It was his opinion that appellant was the perpetrator of the bite mark.

While the experts in the instant case arrived at opposite ends of the analysis spectrum in their interpretation of the particular evidence, one common denominator emerges from their voluminous testimony and the extensive number of exhibits.”

“That common denominator is that forensic odontology, inclusive of bite mark identification, is an exact science. It is exact in the sense that through acceptable scientific procedures, an expert can form an opinion useful to the courts in their quest for the truth.”

Remember this point, Sloan is still “good law” in most states.