Bite Marks in Forensic Dentistry a Review of Legal Scientific Issues

The threshold variable in the analysis of bite points is the fact that in cases of physical aggressions with skin lesions, the anatomy and physiology of the skin, as well as the position in which the victim was located, affect the detail and shape of the bite spot. There is an article from the early 1970s in England by Devore that showed how the positioning of the test bite (in fact, it was a colored circle) on a biceps varied, whether the arm was bent or pronounced. In my recent case, the buttocks are considered an area that does not show large variations in shape, so this was not a problem. Significantly, there is no way to experimentally control or determine the extent of position variation in a real case of bite spot. You can`t (usually) use the actual victim and a deceased person isn`t available either. The bottom line is that skin is usually a material of bad impression. No significant tests on this topic have been published in the odontic literature since 1971. Individual characteristic: A characteristic, characteristic or pattern that represents an individual variation rather than an expected finding within a defined group. An example of this is a twisted tooth. The value of individual traits is that they distinguish between individuals and help identify the abuser.

The number, specificity, and precise reproduction of these individual traits determine the level of trust that a particular suspect has made through the bite sign. Evidence of bite marks led to the conviction of California Innocence Project client William (“Bill”) Richards. During his trial in 1997, a forensic odontist analyzed Bill`s teeth and a trace of a bite found on his wife`s body. The expert testified that only one to two percent of the population could have left the trail of the bite, and he could not exclude that Bill gave the trail of the bite. This led to Bill`s conviction. Years later, in 2007, the same expert retracted his initial statement. Using current science as a support, the expert explained that Bill could not have left the trace of the bite. Bill was exonerated, but the district attorney appealed and the California Court of Appeals overturned Richards` exoneration.

The state Supreme Court later upheld the reversal on the grounds that experts at the time could not withdraw their original statement. Two years later, in 2015, the California Innocence Project lobbied for a new law that would allow experts to withdraw their testimony. After the law was passed in 2016, the California Supreme Court concluded that the bad science of the bite presented during Bill`s initial trial was at the heart of his conviction, and they overturned it. When the image of the ladder is reduced to its original size and shape, the image of the bite mark is also corrected (correction). This assumes that the scale itself is on a single level and that there is no parallax distortion with respect to the bite mark. Although bite marks have been used in many law enforcement agencies across the country, there is no real scientific support or research on the accuracy or reliability of evidence of bite traces. In addition, “experts” often use images to compare a person`s teeth with the bite spot on the victim, which increases the unreliability of evidence of the bite trail. COMMENT: This term “correspondence” or “positive correspondence” should not be used as a final expression of opinion in a Bitemark case. The statement “It`s a positive match” or “It`s my opinion that the bite spot matches the teeth of suspects” is likely to be interpreted by juries as synonymous with specific identification of the perpetrator, if only the dentist could think that an ill-defined or non-specific bite point was generally similar to the suspects` teeth, as could be the case for a large percentage of the population. What is usually argued at this stage is the medico-legal weight (value) that these properties possess. There are orthodontic data on general dental characteristics such as racial variations in skeletal anatomy, jaw width, anterior position of teeth, torsion of teeth (rotation), etc.

They are rarely used in medico-legal cases and there are no specific studies from a medico-legal point of view on the subject. The dentist`s opinion is based on “experience” and, in general, the jury believes or believes this opinion due to other factors included in the dentist`s statement. These factors include years of experience, convincing presentation in court, appropriate use of terminology, scrupulous adherence to the rules of evidence (i.e. Not to mention bringing his notes) and others. This has been acceptable in courts throughout the United States since 1954 (Doyle v. Texas). The advent of DNA profiling in the identification of crimes and certain U.S. Supreme Court cases (Daubert, 1993; Kumho, 1997) sensitized the courts to the nature of scientific evidence in relation to personal opinions.

This led to a generous conversation between the disciplines of forensic identification (ballistics, tool mark analysis, dentistry, fingerprints, anthropology) based on the actual opinion of testimonial experts. This has not created enough pressure to invalidate any of these views in court at this time. What is important, however, is the only area of identification called the examination of the documents in question, which has been severely restricted in its previous extensive involvement in the court on the issue of handwriting analysis. This discussion is simply a trend that is developing slowly. I think there will be many more to come. Class characteristic: A characteristic, characteristic or pattern that is preferably seen or reflected in a particular group. For example, the discovery of linear or rectangular bruises on the midline of a bite spot arc is a class feature of human incisors. The “incisors” in this case represent the class. The value of identifying class characteristics is that, when they are seen, they allow us to identify the group from which they come. For example, the class characteristics of incisors (rectangles) distinguish them from canines (circles or triangles).

If we define the class characteristics of human bites, we can distinguish them from animal bites. By class characteristics we distinguish the adult from the bite of the child or the lower jaw of the arch of the upper jaw. The original term “class characteristic” was applied to tool marks and its definition was changed to make it more applicable to bite marks. If the shape of the bow and bite trail is consistent, assign a point. If the shape of the dental arch is distinctive, and the bite mark matches, assign three points. Example: The suspect has a narrow V-shaped arch and this is reflected in the bite trail. Assign three points. In 1993, the Committee of ABFO`s Bitemark Workshop #2 distributed a questionnaire on the Bitemark methodology. About half of our members responded to the Bitemark Methodology Survey conducted at the three-day Bitemark Workshop in San Antonio from February 12-14, 1994.

The methods used by those who responded to collect and analyze bitemark evidence were presented. This project is an update of the efforts undertaken in the 1984 Bitemark workshop. These guidelines are not intended to invalidate the document prepared following the 1984 workshop. If significant distortion has been detected, it should be corrected before resizing and/or improving the size of the bite trace photo. Only then can a meaningful comparative analysis be carried out. Bite marks have been introduced in trials across the country, and sometimes it was the smoking gun that led to a conviction. Bite marks, an aspect of forensic dentistry, are the process by which dentists attempt to match marks found at crime scenes with suspects` dental impressions. If a victim is bitten by an attacker during a crime and the police have a suspect, dentists may try to “match” the bite track with the suspect`s teeth.

The final analysis of each case depends on the quality of the evidence provided. In cases where all variables are carefully controlled and there are only minor biases, greater certainty of opinion is possible than when the quality of the evidence is low. In this case, the quality of the bite trace photo can be so poor that a meaningful analysis is globally excluded. If all the teeth that can be individually identified in the bite strip are also present in the suspect`s mouth, assign a point. It simply indicates that the marking may have been done by the suspect because he has the necessary teeth. If the number and selection of existing teeth is unmistakable, assign three points. Example: The suspect has teeth 6, 7, 10, 11 and missing # 8 and 9. This was clearly reflected in the marking. Assign three points. If the mark shows teeth that were not present in the suspect`s mouth when he was bitten, the suspect is eliminated. The ladder and bite trail on the plane, but the back of the camera is not parallel to the two. Abrasions (scratches), bruises (bruises), lacerations (tears), bruises, petechiae, avulsions, depressions (depressions), erythema (redness) and perforations can occur with bite marks.

Their meaning and strict definitions can be found in medical dictionaries and medico-legal texts and should not be changed. A cut is a cut made by a sharp instrument, and although it is mentioned in the dickmark literature, it is not an appropriate term to describe lacerations caused by incisors.