In 1992, a Phoenix man named Ray Krone was convicted of murdering a cocktail waitress named Kim Ancona. The crime was brutal. Ancona had been sexually assaulted, stabbed multiple times, and bitten on her breast and neck. Krone was indicted after a local dentist named John Piakis, who had received all of five days of forensic training, told police and prosecutors that Krone’s crooked teeth created the marks on Ancona’s body.

At trial, a more experienced bite-mark analyst from Las Vegas named Ray Rawson confirmed Piakis' findings: The bite marks on Ancona’s neck could only have come from Krone. Rawson included a 39-page report with his testimony. It must have been convincing, because the jury convicted Krone despite no other physical evidence linking him to the crime. He was sentenced to death.

In 1995, Krone was given a new trial after an appeals court threw out his conviction over an unrelated legal technicality. Rawson testified again. And Krone was convicted again. After the second trial, however, the judge refused to sentence Krone to death, writing, "The court is left with a residual or lingering doubt about the clear identity of the killer."

The judge’s misgivings proved prescient. Over the strenuous objections of prosecutors, who maintained that Rawson’s testimony was in itself sufficient to affirm Krone’s conviction, Krone's attorney Christopher Plourd succeeded in getting a court to force the state to turn over biological evidence from the crime for DNA testing. The testing proved Krone was innocent. It also provided a match to Kenneth Phillips, a man who arguably should have been a suspect from the start. Phillips lived less than a mile from the crime scene, was already on probation for assaulting a female neighbor, and was arrested three weeks after Ancona’s murder for sexually assaulting a seven-year-old girl. Several witnesses had described a man fitting Phillips’ height, weight, and complexion to police near the crime scene the night of the murder.

After 10 years in prison, including two spent on death row, Ray Krone was exonerated and released from prison in 2002.

But Krone’s lawyer wasn’t quite finished. In addition to his job as a criminal defense attorney, Christopher Plourd is a legal specialist in forensic science, having served on several government commissions looking at the role of DNA testing in the criminal justice system.

Plourd was livid that his client could have been convicted not once, but twice, based on obviously erroneous testimony that was presented as scientific. It seemed to confirm what Plourd and other critics of bite-mark analysis have long suspected—that there is little "science" behind the method at all. So in 2001, the lawyer decided to conduct a “proficiency test” on some unknowing and prominent bite-mark expert.

Plourd chose Mississippi dentist Michael West for his test. West had long been under fire for dubious testimony in dozens of criminal cases, including one in which he claimed to be able to match the bite marks in a half-eaten bologna sandwich found at the crime scene to the dentition of a defendant. I’ve written extensively on West over the last few years, most recently in a feature about the 1992 Louisiana murder trial and eventual conviction of Jimmie Duncan. In that case, I obtained a video showing West repeatedly jamming Duncan’s dental mold into the body of the young girl Duncan was accused of killing. Forensic specialists say that what West does in the video isn't a remotely acceptable method of analysis, and may amount to criminal evidence tampering. Duncan is on death row in Louisiana, based in part on West's analysis.

Plourd selected West because, even though the dentist was still active in the Mississippi and Louisiana courts, he had been suspended from the American Board of Forensic Odontology since the mid-1990s, and therefore might not be aware of the somewhat notorious Krone case. Plourd was right.

In October 2001, working for Plourd, a private investigator named James Rix sent West the decade-old photographs of the bite marks on Ancona’s breast. Rix told West that the photos were from the three-year-old unsolved murder of a college student in Idaho. Rix then sent West a dental mold of his own teeth, but told him that they came from the chief suspect in the case. He also sent a check for $750, West's retainer fee.

Two months later, West sent Rix a letter and accompanying 20-minute video. In the video, West meticulously explains the methodology he uses to match bite marks to dental molds. Using the photo of Ancona’s bitten breast and Rix's own dental mold, West then reaches the conclusion Plourd and Rix suspected he would: That the mold and the photos were a definite match.

"Notice as I flex the photograph across these teeth how it conforms to the outline very nicely," West explains confidently. "The odds of that happening if these weren’t the teeth that created this bite would be almost astronomical." He adds that the "matching" patterns he found between the photo and the dental mold "could only lead an odontologist to one opinion and that [is] these teeth did create that mark."

Though Plourd’s proficiency test has been noted in court briefs and law journals, this is the first time the video of West’s analysis has been published.

NOTE: The video below includes a photograph of bite marks on a post-mortem breast. Viewer discretion is advised.



Following the methodology that he has used in more than 100 other cases over the years, West confidently matches a dental mold and a photo of bite marks that have absolutely nothing to do with one another, decorating the fiction with the language of science. Though West is dead wrong, he sounds convincing, and it isn't difficult to imagine how he might prove persuasive to judges and juries.

In February, the National Academy of Sciences published a highly critical report about how forensic evidence is used and abused in the courtroom. The study was especially critical of bite-mark testimony, noting that it has contributed to a number of wrongful convictions over the years. The report concludes that there’s simply “no evidence of an existing scientific basis for identifying an individual to the exclusion of all others” using bite-mark analysis. Yet bite-mark testimony is still common, and there are still plenty of people in prison as a direct result.

It would be nice to see more "proficiency tests" like Plourd's with West, only not just from defense attorneys. More importantly, the criminal justice system needs to act swiftly when "experts" like West are shown to conduct bogus examinations.

West failed Plourd’s test in 2001. Yet as late as 2003, the Mississippi State Supreme Court still upheld West’s bite-mark testimony in a murder case. In rejecting an appeal by convicted murderer and death row inmate Eddie Lee Howard, the court wrote that “Just because Dr. West has been wrong a lot, does not mean, without something more, that he was wrong here.” And as late as 2006, Mississippi District Attorney Forrest Allgood relied on West’s bite-mark testimony to keep rape and murder convict Kennedy Brewer in prison. Though DNA evidence had shown back in 2003 that Brewer didn’t commit the rape, Allgood argued that because West matched bite marks he claimed to have found on the victim to Brewer’s teeth, Brewer must have bitten the victim while someone else raped her. (Other analysts say the marks weren't even bites.) Brewer remained in prison an additional five years, and was only released in 2008.

Plourd’s video sting ought to move public officials in Mississippi and Louisiana to thoroughly, if belatedly, investigate just how much damage this dentist has inflicted on the judicial systems of those states. There are still dozens of people in prison due in some part to "expert" tetimony that has been shown to be anything but.

Radley Balko is a senior editor at Reason magazine.