Bite Marks | Objective Opinion and Junk Science

Error Rates

In 1993, the U.S. Supreme Court wrote in its decision regarding Daubert v. Merrell Dow Pharmaceuticals, Inc., that among the many factors for courts to consider when admitting the evidence is the ‘potential error rate’ of a scientific method. The Daubert Standard and the Frye Standard (1923, Frye v. The United States) have come to be considered the written standards for what forensic evidence can be admitted into trial courts as a basis for the ruling. As science changes over time, our abilities to understand our world evolve, it would seem that the evolution of our court processes would follow to keep up with the science and values of the time. The government has always needed a little prodding to keep up.

If a conviction is set to be decided based on forensic evidence, for matters of truth in decision making, the error rates for the given forensic testing should also be stated. To hold someone’s life in your hands as a jurist, not having a scientific background, would you want the man in the lab coat presenting his testimony that he believes ‘X is a match Z’ also to tell you those lab findings are only 50% correct? These are but slight details.

The only sure forensic evidence is DNA evidence. All others are fallible; they are simply junk science. Many individuals have been falsely convicted based on junk science. In the year 2020, thanks to groups like the Innocence Project, a non-profit legal group working to change wrongful convictions, the U.S. legal system has been turned on its head and forced to take a hard look at its mishandling of truths when it comes to hard science and facts.

What is Forensic Odontology?

Otherwise known as forensic dentistry, is the application of dental knowledge and skills to the matters of courts, police, crime-solving, and body identification. Indisputable court evidence can be obtained in dental remains. It takes a specialized certification for a dentist to practice forensic dentistry for legal purposes.

Some dental findings can be fundamental and essential in solving crimes or discovering the identity of remains found. Forensic dentistry involves the proper handling, examination, and evaluation of dental evidence. From this type of evidence, an examiner may discover the age, identity, DNA, race, and even occupation. Teeth can even give clues to the socioeconomic status of the victim. If available, examiners can compare teeth to previous dental records to help provide an identification. This identification process is done through a comparison of films taken before and after death.

There are many reasons the courts and legal systems use forensic dentistry. Some of these uses are very valid, as listed above. However, some services of forensic odontology have been used to convict and identify individuals as criminals falsely. The use of forensic bite marks as a form of suspect identification has come under scrutiny. Like many of the forensic sciences, its validity in the courtrooms is being questioned.

Bite Marks Used for Identifications

A study was produced in 2009 by the National Academy of Sciences entitled: “Strengthening Forensic Science in the United States: A Path Forward.” The report was damning for the American judicial system. They presented problems with every forensic science available except DNA. The scope of the information can be summed up in this comment. Excluding DNA analysis, the report found, “no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source.”

This concept matters tremendously to those whose lives have been impacted by junk science. Keith Allan Harward was convicted of the 1982 rape of a Newport News woman and the murder of her husband. The challenge was that Harward insisted he was innocent during and after his trial. One, in which he would be convicted as guilty, based on bite marks.

The jury listened carefully as six forensic scientists testified that Harward’s teeth matched bite marks that were found along the rape victim’s legs. For years, courts across the United States accepted forensic odontology as a verified source of science. The problem one could suspect is that those who are legislators are also not scientists. The ability to be a public trust and write legal statutes is not a study in the scientific method. With the capability of so many specialists to direct our judicial system, understanding the percentages of truth should not have been so difficult.

Most jury members are your neighbors, the local small business owner, the mother of the young boy who mows lawns, or a single young man just getting on his way. Juries are and can be anyone, but to have a significant scientific background making up any single jury is not likely. If the court and scientists tell you to deduce your decision from facts as presented, then the fault lies with the court for not understanding the science.

After hearing six expert forensic scientists testify that Harward can be identified as the biter of the woman, the jury convicted him. It took many years to get the courts to look at a newer available science, DNA analysis, to discover that he was innocent. However, during court, Dr. Lowell Levine, an AFBO board-certified expert, testified that there was “a very, very, very high degree of probability—so high that it would be a practical impossibility” that anyone else could have bitten the victim. The jury then listened to another AFBO board-certified expert; Dr. Alvin Kagey testified that Harward had made the marks “with all medical certainty that there is just not anyone else that would have this unique dentition.”

On April 27, 2016, the Virginia Supreme Court declared Harward innocent, wrongfully convicted based on junk science. Harward had spent 33 years of his life in prison. Keith Harward has vowed that he would use his time left to work on preventing others from being wrongfully convicted. He has stated that any time in the future where bite mark evidence is used in the future, he will show up. Harward wants everyone to know that it isn’t real science. He said, “I will contact the media. I will stand on the street corner in a Statue of Liberty outfit with a big sign saying, ‘This Is Crap.'”

Objective Opinions & Junk Science

How could this have happened? There is a great deal of difference between a DNA match and a bite mark match. One test is done scientifically, is measured, and the results are factual. The other is done by human comparisons, visual referrals, ideas, and personal objectivity. Knowing how the science is collected, tested, and compared can make a great deal of difference in the measurability of the ‘truth’ behind the results.

Of all the different types of evidence that the NAS report found faulty, it seemed that it was the forensic dentists that got their feathers ruffled the most. Indignity does not become a profession; what should matter most to forensic scientists, regardless of background occupation, is finding the truth.

The problems that arise from bite mark evidence comes along two avenues of proof—the first being identifying a pattern mark on a victim as an injury left by human teeth. The second is to attempt to match the marks to the impressions of a suspect’s teeth. Regardless of how either of these areas is investigated, measured, studied, the end conclusions are not scientific at all, but mere personal opinion.

After the release of the NAS report, the President’s Council of Advisors on Science and Technology in 2016, rebuked the entire field of dental forensics by making this statement. “Available scientific evidence strongly suggests that examiners cannot consistently agree on whether an injury is a human bite mark and cannot identify the source of a bite mark with reasonable accuracy.” PCAST went even further, stating that they felt that any future benefit to further develop the advancement of bite mark science to be extremely low or limited.

The problem does partially seem to be in the very nature of bite mark evidence. Marks left on the skin can vary, move, stretch, or change over time. The science begins flawed.

When a case is set for analysis, gaining samples of marks left on the skin is relatively straightforward. Photography, dental casts, transparent overlays, computer enhancements, electron microscopy, are all typical ways to enhance the views and study the affected areas. Swabbing can be done for serology or DNA. What skin looks like at the time of the study, or how DNA results are returned are direct and easy to understand. What can severely limit the case to use forensic dentistry at all to match bite marks is that bite marks are distorted in varying degrees by the elasticity in one’s skin. Swelling and healing can move the original marks, change them, and stretch them. Another issue can be that people’s teeth change and shift over time. These are just a start looking into the problems involved in comparisons, and the accuracy of any valid results or conclusions from these tests is slim.

While it may be true that these forensic dentists believe in their lifelong work, the ability for bite marks to be an available forensic science for trial courts does not meet all of the required guidelines for scientific evidence. The American Board of Forensic Odontology (ABFO) indeed lists numerous ways in which testing can be done and compared; it fails to provide probability numbers for any of the tests it approves. The trouble is, it is impossible.

There have been no studies conducted to establish the differences in bite marks. Unlike DNA, there is no central repository of bite marks and dental casts. There is no way to make comparisons with enough individuals to determine the accuracy of the findings for bite mark analysis because it is not science at all, but an objective opinion. Science admitted into trial courts must follow either or both the Frye Standard or Daubert Standard. According to both of these standards, the acknowledged science must be of sound relevance and proven reliability. Bite-mark evidence has neither. If the science could never produce its probability of failure to the courts, it should have never been admitted as evidence into the trial court process, to begin with.

Falsely Convicted

What can be done now? Prosecutors, lawyers, judges, and forensic odontologists must admit their shortcomings and prepare for a bigger future. The entire process must be done for seeking truth and delivering justice, or attempting to have a civil society is a wasted effort. Those who have studied forensic dentistry still have much to give to the courts, and a long way to go to take their science. These dentists can still help solve a crime, identify victims, and many other areas of investigative analysis. Bite marks, however, have a way to go.

Bite-mark evidence has been behind more than 31 wrongful convictions that have been overturned recently. Robert Lee Stinson served 23 years of a life sentence for the brutal rape and murder of a 63-year-old woman. The only evidence tying him to the crime was bite mark evidence. In 2009, at the age of 44, he was released from prison, when the Wisconsin Innocence Project showed that the DNA was not a match.

As recently as 1995, Gerard Richardson was sentenced to 30 years in prison without the possibility of parole. The evidence that the jury had convicted him on was bite mark evidence that the forensic scientist Dr. Ira Titunik had testified “was made by Gerard Richardson… there was no question in my mind.”

This testimony was followed up by the prosecutor who elaborated on this with “Mr. Richardson, in effect, left a calling card… It’s as if he left a note that said, ‘I was here,’ and signed it because the mark on her back was made by no one else’s teeth.” With that information, the jury convicted him. On December 17, 2013, the decision was overturned after Gerard had spent nearly 20 years in prison.

What is the Value Now?

While there are many more cases that have been and are currently being overturned, for forensic analysts, crime scene investigators, first responders, and law enforcement, where does that leave any value in collecting this type of evidence?

Every piece of evidence tells a part of the story. It is wrong to have the idea that this piece or that bit of evidence will be the “match” that puts a criminal behind bars. All evidence is there to describe the scene, to help the judge, the jury, and others understand what happened, how it happened, and if possible, why. With crime, though, the why is not always a reasonable idea, which would make sense to the everyday person—presenting the ‘why’ is precisely why the collection process includes every detail.

Making sense of chaos isn’t always easy. Not for experienced judges, and we put the verdict in the hands of those who are inexperienced, who do not have the background to comprehend the reality of the situation that is often thrust before them. Value is found in the ability of evidence to weave together the fabric of time in which the crime was created so that these innocent onlookers can attempt to understand all of the players’ parts in the story. In this light, every piece of evidence has value, and collecting, storing, and processing each piece according to protocols is the best chance that any legal recourse can be made in crime.