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Death Sentences: A Trail of Dubious Contributions to Justice

By: , Posted on: January 28, 2015

Dental_evidence_ted_bundyThis article originally appeared on, Michael’s personal blog. Click here for the original article.

I have reported on this subject before, as the continued acceptance of the bitemark id “pseudoscience” in US courts still allows this prejudicial type of prosecutorial expert opinion to be considered “relevant evidence.”

Continuing on this topic, my experience as a defense expert in three specific cases that involved sentences of death and execution deserves presentation about the tangled web of the history of “bitemark expertise” now under review by the National Forensic Science Commission and its OSAC (subcommittees).


1. All cases involved AAFS/ABFO dentists as prosecutorial experts. I was involved in litigation after convictions had been achieved at trial. Two were past presidents of the ABFO, one of whom was also a past AAFS president. I was an AAFS/ABFO members during my participation. I resigned from the ABFO a few years later in 2012

2. All three cases were charged as capital murder which invoked the death penalty.

3. All cases had females as murder victims. One was a multiple murder of 2 high school students.

4. One case involved the use of a jail house informant who later was found to be incentivized. The informant testified against the defendant in case three described below. The prosecution dentist identified the defendant as biting the victims. While in prison, the informant wrote a letter to the mother of the defendant saying he had lied about the defendant. She soon was murdered after informing the Waco, TX police of the letter. From THAT case, the same dentist testified against another defendant via a bitemark id. That man was later exonerated.

5. One case had post conviction DNA obtained and tested during appeal.

6. Two executions, one exoneration. The exoneration case has become one of the rallying cries against continued use of bitemark identification “science” in criminal courts.

7. One lawsuit happened post execution between the DA and police chief against a newspaper corporation for defamation. The newspaper lost. I reviewed relevant dental evidence used at the trial by the prosecution years after the execution.

8. One case was a last minute appeal days before execution.

9. One case is from Arizona and two are from Texas.

10. The twist: last case has one dentist involved in a fourth case that was connected to the third case.


AZ. The exoneration: My Ray Krone blog is here with links. One of the Krone dental defense experts, Norman Sperber, is also involved as a prosecution expert in the ongoing criminal conviction appeal of William Richards in California. He opined for the prosecution that “two out of 100″ humans had a specific tooth position he now refutes was a bitemark. The California Innocence project has litigated his case for years and is promoting statutory forensic and judicial reform.

TX. The last minute appeal before execution. My report to the Center on Wrongful Conviction regarding Humberto Leal bitemark “identification evidence” which led to his execution. Leal_Affidavit_Bowers. The state’s dental expert rendered as amazing statement at the original trial. “The bitemark on ME#XXXXXX are consistent with the dentition of Mr. Humberto Leal and therefore were inflicted by him.” (Page 8 in my affidavit).

TX. The post execution case review in a lawsuit. The David Wayne Spence case started with his conviction for multiple murder. The State used a well established bitemark dentist who claimed Spence left a couple of bites, identifiable only to Spence’s teeth, on the bodies. There was also a jailhouse informant that testified against Spence. He wrote the letter to Spence’s mother who was murdered. In an odd twist of multiple related casework from the same dentist other things occurred that are troubling. After conviction and sentencing to death, Spence’s case roiled through the media for years. Not surprisingly in some death cases (not in Leal’s), objections to the state’s case and the jail informant was huge in Texas and ultimately went personal with the lawsuit from the prosecution and law enforcement types. The suit included the state’s forensic dentist as a plantiff.

It is important to know that the Spence prosecution’s dental expert, Dr. Homer Campbell (dec’d), years later was a contributor to a conviction in Texas which later became a DNA exoneration litigated by the Innocence Project. As described above, there is a very interesting connect with this case to Spence. Calvin Washington is the exoneration.

Dr. Campbell was also a defense expert in the Ray Krone’s criminal case. Unfortunately, he also was in the center of another bitemark opinion reversal in the State of Arizona v. Garrison in 1978 where he had rendered an opinion that “eight in one million” humans had front teeth like a criminal defendant’s.

Read more from Michael:

Michael’s most recent book Forensic Testimony: Science, Law and Expert Evidence is available on the Elsevier store for a 30% discount. Just use discount code “STC215” at checkout and save!

About Michael Bowers:

Michael BowersC. Michael Bowers, DDS, JD is a practicing forensic dentist and consultant who has testified and worked on hundreds of cases where dental evidence has been involved. He is a Senior Crime Scene Analyst for the International Association for Identification (IAI) and has written other articles, chapters and books on forensic dentistry. He owns and operates his own dental practice in Ventura, CA.

Additionally, he is a Fellow of the American Academy of Forensic Sciences and a past member of the editorial board for the Journal of Forensic Sciences. He is author of Forensic Dental Evidence, published by Elsevier’s Academic Press in 2010, and his new book, Forensic Testimony: Science, Law and Expert Evidence will be published in October 2013.

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Forensic Sciences

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