Bite mark evidence has long been a discredit forensic science. The FBI has renounced it and the American Dental Association does not recognize it.


And for good reason.


In June 2013, USAToday reported that 20 men convicted or charged with murder or rape based on bite mark evidence were subsequently exonerated.


Bite Mark Evidence Rejected


Two years ago the Texas Forensic Science Commission, made up of scientists, practitioners, and law enforcement officials, became the first state agency in the nation to discredit bite mark evidence by recommending its use in Texas criminal trials be suspended until further research could be conducted into its reliability.


Man Exonerated After 28 Years in Prison


The Commission’s recommendation came after the integrity unit of the Dallas County District Attorney’s Office cleared Steven Mark Chaney of a brutal 1987 drug-related double murders. Cheney had served 28 years on the wrongful conviction before the New York-based Innocence Project managed to develop evidence of his actual innocence and secured his release in October 2015.


“For far too long courts have permitted this incredibly persuasive evidence that is cloaked in science, when in fact there has been no scientific research to substantiate the practitioners’ claims that it is possible to identify someone from a bite mark,” said M. Chris Fabricant, the project’s director of Strategic Litigation, in a news release at the time. “By recommending a moratorium on further use of this unscientific evidence in Texas prosecutions, the Texas Forensic Science Commission has taken a giant step in purging unscientific and unreliable bite mark evidence from court rooms nationwide.”


Forensic Experts Testified Falsely


In August 2016, former Dallas County Assistant District Attorney Neil Pask told a local criminal district court that Chaney should not have been convicted or even charged with the double homicide. Evidence developed at that hearing indisputably established that a state forensic expert testified falsely when he told the jury that convicted Chaney he was absolutely certain that there was only one chance in a million that a bite mark found on the arm of one of the victims had not been made by Chaney.


Another state expert witness also falsely testified that the bite mark had been inflicted at the time of death when he had previously concluded in the original autopsy report that the wound had been inflicted two or three days before the victim’s death.


Prosecutor Pask told the jury in his closing argument at trial that he would not have even indicted Chaney absent this bite mark evidence. The state’s case against Chaney rested essentially on the flawed bite mark evidence and the false testimony presented to support it.


State Violated Brady Rule


For that, an innocent man spent 28 years in prison before he was able to actually establish his innocence. The district court that heard his post-conviction habeas corpus petition made the following four factual and legal conclusions:


  • New scientific evidence contradicts bitemark-comparison evidence relied on by the State at Cheney’s trial;
  • His conviction was secured using false evidence;
  • The State violated the Brady rule through suppression of favorable and impeaching evidence; and
  • Cheney was actually innocent.


The State, through the Dallas County District Attorney, agreed with these findings.


Bite Mark Evidence Completely Repudiated


The district court’s findings were submitted to the Texas Court of Criminal Appeals for its review. In a thorough 68-page opinion written by Justice Barbara Hervey in which bite mark evidence was completely repudiated, that court on December 19, 2018 reached the following conclusion:


“Each piece of the State’s trial evidence is questionable ‘or has since been undermined or completely invalidated’ … When weighing Chaney’s newly discovered evidence against the State’s trial evidence, we conclude that Chaney has shown by clear and convincing evidence that ‘no reasonable juror would have convicted [him] in light of the new evidence’ … Chaney has proven in his actually innocent.”


The Chaney decision puts a stake in the heart of the corrupt prosecutorial misconduct that former Harris County District Attorneys Johnny Holmes and Charles “Chuck” Rosenthal, Burleson-Washington County District Attorney Charles J. Sebesta, and Williamson County District Attorneys Ken Anderson, John Bradley, and Jana Duty institutionalized in the Texas criminal justice system—that is, before significant change came.


Texas voters have demonstrated in recent elections that they are fed up with district attorneys who promise law-abiding service but who routinely engage in some form of unethical or official misconduct, and the Texas State Bar has demonstrated it will take disciplinary action against those prosecutors who cannot obey the rule of law.


There are still rogue prosecutors in the Texas but the fact that integrity units have been established in Harris, Dallas, Bexar, Tarrant and Travis counties;  and the fact that the Texas Legislature has enacted the Michael Morton Act, post-conviction DNA testing, and Article 11.073 of the Texas Code of Criminal Procedure (defendant can receive post-conviction relief based on change of science relied on by State at trial) lends hope to criminal defense attorneys that not only will these rogue Texas prosecutors be held accountable but that innocent people will have venues of relief.


We applaud the Innocence Project, the Dallas County district court, the integrity unit of the Dallas County District Attorney’s Office, and Court of Criminal Appeals for their roles in establishing Steven Chaney’s actual innocence.