Forensic bitemark analysis, a commonly used form of evidence
Insufficient Data and Scientific Backing
Published in the Journal of the California Dental Association, the research presents a compelling case against the reliability of bitemark analysis. Lead author Mary Bush, Associate Professor at the State University of New York in Buffalo, NY, highlights that the scientific community does not support the notion that human teeth possess unique features that transfer reliably to human skin. This undermines a fundamental premise of bitemark analysis.
The study’s dataset reveals significant discrepancies and malalignment between the upper and lower teeth, leading to fewer matches and greater distortion in the lower teeth. By examining actual indentations left on the skin, the researchers found that even within a population of 1,100 people, a substantial number could have produced the bite with just 25% distortion. These findings are a cautionary tale regarding the dangers of relying on bitemark analysis in court trials.
Wrongful Convictions and the Consequences
The consequences of relying on bitemark evidence are both tragic and far-reaching. The research conducted by Bush and her team indicates that 26 individuals have been wrongfully convicted due to this flawed forensic technique. Shockingly, some of these individuals were sentenced to death, emphasizing the urgency of addressing this issue.
One such case is that of Keith Allen Harward, who spent 33 years in prison for a crime he did not commit. The primary evidence against Harward was a bitemark found on the victim’s skin. The jury was swayed by a forensic dental expert’s detailed explanation of how Harward’s teeth matched the bite. Subsequent DNA
Eddie Lee Howard is another example of the devastating consequences of relying on bitemark evidence. Sentenced to death in 1994 for the murder of a white woman, Howard spent 26 years on death row before being exonerated. The Innocence Project, an organization dedicated to freeing wrongly convicted individuals, played a pivotal role in his release. His innocence was finally proven by introducing new forensic opinions, powerful alibi witnesses, and DNA evidence excluding Howard as the perpetrator.
Questioning the Validity of Bitemark Analysis
The research conducted by Bush and her team aligns with prior studies challenging the validity of bitemark evidence. In 2009, the National Academy of Sciences (NAS) released a comprehensive report on forensic science
A recent review by the U.S. National Institute of Standards and Technology (NIST) further supports the doubts surrounding bitemark analysis. The study found a need for more consensus among practitioners regarding the interpretation of bitemark data and the accuracyIn scientific and measurement contexts, "accuracy" refers to the degree of proximity or closeness between a measured value and the true or actual value of the measured quantity. Accuracy indicates how well a measurement reflects Read Full Definition of analysis techniques. Additionally, it highlighted the need for more scientific support for three critical premises of bitemark analysis:
- The uniqueness of human dentition at an individual level
- Accurate transfer of dental characteristics to human skin
- Precise"Precise" refers to the degree of closeness or consistency between multiple measurements or values taken under the same conditions. It indicates how well these measurements agree with each other, regardless of whether they are accurate Read Full Definition capture and interpretation of identifying characteristics
Raising Awareness and Ensuring Justice
To raise awareness about the unreliability of bitemark evidence, the study’s authors aim to present their findings at national meetings and publish them in peer-reviewed journals. By highlighting the potential issues with this form of evidence and the liabilities associated with testifying in trials, they hope to initiate a broader conversation within the legal and scientific communities.
The implications of these research findings extend beyond individual cases, calling into question the justice system’s integrity. As the flaws of bitemark analysis become increasingly apparent, it is crucial to reevaluate the reliance on this technique and seek alternative methods supported by robust scientific evidence.
In conclusion, forensic bitemark analysis in court trials lacks a scientific foundation, resulting in wrongful convictions. The research conducted by Mary Bush and her team emphasizes the unpredictable nature of bitemark evidence and the potential dangers associated with its use. Urgent reforms are needed to ensure that the justice system relies on sound scientific methodologies to guarantee accurate outcomes in court trials.