Forensic Research Paper

The purpose of this research is to critically analyze the various components of forensic anthropology and odontology in order to obtain an accurate understanding of the overall reliability of these disciplines. Research obtained from various sources including, textbook, peer reviewed articles and the National Academy of Sciences Report are examined in an attempt to explain how the field of forensic odontology, more specifically the discipline of bite mark analysis is not considered to be a reliable or credible source in the criminal justice system.

There are many disciplines in forensic science. Some have been scientifically proven to be reliable while others are still facing scrutiny. One of the disciplines that have been deemed reliable is Forensic anthropology. Although some aspects of it still do not give 100% factual information, the information it does provide is an estimate. Those estimates still give investigators enough information about the skeletal remains that they can usually start moving forward in the investigation. A subcategory of anthropology is odontology. Usually these two disciplines work closely together when identifying human remains, especially if there are teeth involved. Although forensic odontology is an essential aspect in helping identify human remains, the bite mark analysis aspect can be very unreliable and varies from case to case. The inconsistency of bite mark analysis makes that area of odontology unreliable. This paper will examine how forensic anthropology is used in criminal investigations to help identify human remains. Also, it will examine odontology. Finally, it will examine the unreliability of bite mark analysis.

Forensic Anthropology is the scientific discipline that applies the methods of physical anthropology and archeology to the collection and analysis of legal evidence. It is a specialty within physical anthropology and it involves the processing and analyzing of human skeletal remains to assign biological identity and to describe the state of the remains. The remains they examine are often absent of flesh or the flesh remaining has decomposed to a point where an autopsy is not possible. Therefore, the skeletal parts rarely offer any evidence of the actual physiological events leading to death. Forensic anthropologists are not often in a position on their own to determine the manner and/or cause of death, however, they do work closely with other forensic and/or medical professionals such as pathologists to accomplish this task.

Unlike other forensic science disciplines, anthropologists deal with the skeletal remains to try and identify who the subject is. There are certain bones that can help indicate a subject’s age, sex, race and stature. The ultimate goal is for the anthropologist to be able to identify all of these characteristics to build a profile of the subject. There are several ways to identify the age of the victim, but according to Burns (1999), “no aging method is even close to being 100% accurate” (p. 150). Therefore, the anthropologist must give an estimated age of the subject. Even though it is just an estimate, it still gives the investigators enough information to work with, especially if the other characteristics are identified.

Along with identifying the age of the subject, the sex of the subject is just as essential. Identifying the sex of the victim is a little easier than age because there are fewer alternatives. If the deceased is an adult, the probable sex can be determined by examination of the pelvis, skull and other bones (Killam, 2004, p. 5). When the anthropologist determines the sex via the remains, it eliminates potential subjects as well as narrows down the possibilities of whom the remains belong too.

Another important characteristic that should be identified in order to help the investigation of identifying skeletal remains is race. However, the identification of the subject’s race can be difficult since the skeleton does not have any distinctive characteristics that define racial characteristics (Siegel & Mirakovits, 2011, p. 262). Most of the recognizable racial traits are found on the head, but body types and proportions vary as well (Burns, 1999, p. 152). Although determining the subject’s race is difficult, once the race is established – just like age and sex, it further narrows down the possibilities of whom the remains belong too.

The final characteristic that contributes to the identification the skeletal remains is the stature of the subject. Stature can be measured by using several reliable methods. If the skeleton is still articulate, then the length can be measured. If it is disarticulated, but the head, spine, pelvis, and at least one leg bone is present, then the individual bone heights can be measured. (Sorg & Haglund, 2009, p.115). Although the stature of the victim is viable piece of information for the investigators, sometimes there are implications with the use of stature. The estimate of the stature may be accurate, but the records of the missing person are entirely wrong (Burns, 1999, p. 157). This could lead to the incorrect identification of skeletal remains. However, not all missing people reports are wrong. Therefore, the use of stature is still a significant piece of information when trying to identify the skeletal remains.

Cause and Manner of Death

Even though forensic anthropologists aren’t legally allowed determine cause and manner of death, they do work closely with the pathologist and/or medical examiners to help identify the critical events that may have taken place that caused the subject’s death. They are able to contribute to the interpretation of skeletal trauma and make judgements regarding the timing of the trauma (Sorg & Haglund, 2009, p.117). If there are injuries to the bones, the anthropologists are able to analyze and possibly determine the nature of the injury.

Houck & Siegel (2006), suggest that “one of the most important distinctions when analyzing the skeletal remains is determining the difference between ante-mortem (before death) and post-mortem (after death) injuries” (p. 213). Ante-mortem injuries are easily identified because there is evidence of healing of the bone. Since the majority of people experience injury at some point in their life it is easy to compare an ante-mortem x-ray to a post-mortem x-rays (Siegel & Mirakovits, 2011, p. 266). Although post-mortem and peri-mortem (at time of death or near time of death) are more difficult to differentiate between, there are ways to distinguish a difference between them. Since there is no time for the body to heal there isn’t any sign of healing. Therefore, to distinguish between peri-mortem and post-mortem, the forensic anthropologist must identify if the injury occurred on fresh bone and not dry bone (Burns, 1999, p. 159).

Along with determining the time that the injury took place, the type of injury that occurred is just as important. A forensic anthropologist must first isolate evidence of skeletal trauma from natural variations and subsequently determine the nature of trauma (Davidson, Davies, Randolph-Quinney, 2011, p. 184). The trauma that forensic anthropologists’ usually examine is blunt and sharp force trauma as well as gunshot wounds and patterned injuries. Blunt force trauma produces impact marks or fractures and can fragment bones (Sorg & Haglund, 2009, p.117), whereas sharp force trauma produces “cutting wounds”. Each type of blade creates its own pattern of damage and other tools leave distinctive patterns, such as a hammer and screwdriver. Finally there is the gunshot wound, which is dependent on the type of weapon, projectile, range and trajectory (Burns, 1999, p. 160).

Implications of Forensic Anthropology

Although the methods used in forensic anthropology have been proven to be reliable when identifying skeletal remains and contributing to the determination of cause and manner of death, it has faced scrutiny because of several factors. One being that education is lacking in Canada. According the Hart House Report (2012), “to date there are no dedicated training programs or certification in the field offered in Canada”. Also, “it is impossible to obtain a graduate degree in this field in Canada” (p. 21). Since there are no training programs available it is hard for the forensic anthropologists to advance. If they do want to attend training they would have to travel elsewhere, where the training would be provided. Also, since it is impossible to obtain a graduate degree in forensic anthropology, the students interested in pursuing this career would have to go elsewhere, which could be a major burden and make students aim towards another career.

Another issue mentioned in the Hart House Report (2012), was that the facilities for the practice of forensic anthropology vary from province to province (p. 21). Also, since the discipline does vary from province to province it makes it difficult to mandate professional standards across the nation. However, every anthropologist report is reviewed by a forensic pathologist, as part of the peer-review process for all pathologist case reports (Hart House Report, 2012, p. 23-24). Thus, at least the reports are being peer-reviewed, which makes the legitimacy of the report that much more reliable in some aspects. It is concerning having a pathologist review an anthropologist’s report, considering pathologists normally aren’t specialized in the study of skeletal remains.

Along with the implications set out in the Hart House Report, there are some aspects of forensic anthropology that do have their shortcomings. A lot of the work anthropologist do is based on estimates. Even though this does potentially lead to the possibility of the human remains being identified, it can also lead to the subject not being identified because of the estimations or misinformation that is available to the investigators at the time. Also, some of the time, forensic anthropologists don’t have all the bones from the skeleton available. If they are missing the bones that are crucial in determining the identity of the subject, then the bones found are essentially useless.

Odontology

According to Siegel and Mirakovits (2010), forensic odontology is the examination of human dentition for forensic purposes, such as determining the identity of human remains, approximating the age of a person, analyzing bite marks, and examining the dental structure of a person suspected to be a victim of abuse. (p. 255). Siegel and Mirakovits (2010) suggests that odontology is part of forensic medicine and is used in law enforcement to estimate the age of a living or dead person and to uncover the identity of human remains especially when there has been a tremendous amount of trauma/damage inflicted upon them or subsequent decay to their body, often as a result of criminal activity or natural disasters (p. 268). Like forensic anthropology, odontology is used to determine age of the subject and help identify skeletal remains.

Determining Age of Subject

There are a few well-known and commonly used methods in identifying the age of a human being from their dental remains. According to Forensic Dentistry (1997):

Aspartic acid racemization has been used for age estimation based on its presence in human dentin. Most protein components in the body consist of L-amino acids, whereas D-amino acids have been found in bones, teeth, brain, and the eye’s crystalline lens. D-amino acids are believed to have a slower metabolic turnover and subsequently a slower decomposition rate. (p. 3)

This research emphasizes the fact that human teeth possess D-amino acids, which subsequently slow down the rate of their decomposition after death. The fact that teeth decompose at a slower rate in comparison with the rest of the body is what allows experts in the field to use them as an accurate source in predicting an individual’s age.

An individual’s age can also be determined by the development of the subjects teeth. According to Burns (1999), “tooth formation and eruption are very useful for determining the age of infants, children and young adults.” (p.122). However, there are individual differences and population differences. In addition, Forensic Dentistry (1997) explains that “Maples (1978) reported on an improved technique of using dental histology for estimating adult age by using multiple regression analyses…. “ (p. 4).

Identifying Human Remains

Forensic odontologists have been an essential aspect in helping identify skeletal remains. Sometimes all that is left behind for evidence is the teeth of the subject. With only this evidence to work with, the odontologist is called upon to process the remains. Since teeth are made of enamel, the hardest substance the body produces, and can survive severe conditions and still be viable for analysis (Houck & Siegel, 2006, p. 207-208), they become a significant piece of evidence used in the identification of unknown subjects. .Even though teeth are just another part of the skull, the amount of info in one tooth makes it a subject unto itself (Burns, 1999, p. 110).

One way to identify the remains is to compare post-mortem x-rays with ante-mortem x-rays, like in forensic anthropology, this comparison can lead to the identification of the subject. Since most people regularly visit their dentist they have dental records and x-rays that on file, which can assist in an investigation (Houck & Siegel, 2006, p. 210). Also, if there is a little bit of tissue left on the teeth, then it may be extracted from the teeth and used in combination with other technologies to positively identify the individual. In the event that no tissue can be obtained from the dentition and no similar dental records can be found, it is still possible to identify the race and sex of the individual in question. According to Forensic Dentistry (1997):

Sex differences in dentition are based primarily on tooth size and shape. Male teeth are usually larger, whereas female canines are more pointed and have a narrower buccolingual width. There also appear to be greater differences in size between maxillary central and lateral incisors in females as compared to males. (p. 10)

In regards to identifying the race of an individual through dental remains, Forensic Dentistry (1997) suggests that:

Both the mandible and dentition reflect racial characteristics. The most useful racial clue in dentition is “shovel-shaped” incisors found in most Asiatic Mongoloids and Amerindians and in less than 10% of whites and blacks. Tooth size and shape including shovel tooth incisors, Carabelli’s cusp or tubercle, enamel pearls, and dental pulp shape (taurodontism vs. cynodontism) have been listed as racial determinants. (p. 11)

Bite Mark Analysis

Although there is controversy around bite mark analysis, they have been used to identify victims and assailants from the beginning of recorded history. However, the research of Avon (2004) indicates that bite mark patterns must be clearly recognizable and distinguishable in order for them to be used as evidence and that there isn’t a universally recognized method for bite mark analysis among the scientific community. Because there is no single method for the analysis of bite mark evidence, the particular method used would depend on the circumstances of each case and on the preference and ability of the analyst (p. 456). Therefore, a positive bite mark does not convict a suspect of a crime. It only places the victim and the suspect in intimate proximity (Glass, 2009, p. 94).

Even though bite mark analysis has been use in several cases that led to convictions throughout the years, the credibility of it is still disapproved by some in the forensic science community. According to Lock (2012):

Bite mark evidence, as with most forensics, is a discipline based upon conclusions resulting from flawed inductive reasoning and an absence of true scientific and statistical validation. In addition to that, the discipline has been woefully lacking in controls on process, procedure, and competence. In the field of forensic odontology, as recently as 2010, the following problems still exist with bite mark analysis: New forensic odontologists have too little experience in bite mark analysis, there is no requirement to seek second (or third) opinions in bite mark cases, and there is no mandatory proficiency testing for certified forensic odontologists. The major issues are that human dentition has not been scientifically determined to be “unique’, and human skin is so flexible, compressible, and expandable that it cannot be relied upon to accurately maintain and display an impression made on it. (para. 4-5)

The National Academy of Science Report on Forensic Odontology (n.d.) indicates that:

The uniqueness of human dentition has not been scientifically established, the ability of the dentition, if unique, to transfer a unique pattern to human skin and the ability of the skin to maintain that uniqueness has not been scientifically established, the ability to analyze and interpret the scope or extent of distortion of bite mark patterns on human skin has not been demonstrated, the effect of distortion on different comparison techniques is not fully understood and therefore has not been quantified, and a standard for the type, quantity, and number of individual characteristics required to indicate that a bite mark has reached a threshold of evidentiary value has not been established. (as cited in Locke, 2012, para. 6)

Therefore, this aspect of odontology can be deemed unreliable and needs further research to be recognized as a valuable piece of forensic science.

Conclusion

The discipline of forensic anthropology has been around for hundreds of years in helping identifying skeletal remains. The aspects of forensic anthropology have been proven to be reliable source of scientific information and have gained credibility in the forensic community. Forensic anthropologists are able to identify several characteristics which helps lead to identifying skeletal remains. They can identify the age, sex, race, stature of the victim and sometimes the cause and manner of death. This information has led to positive identifications throughout the years. Although forensic anthropologist play a key role in the forensic community they still face some scrutiny because of the lack of training, accreditation and education available in Canada. In addition, there are no professional standards set out and the practice varies from province to provinces, which can lead to questioning in the courtroom when forensic anthropology is being used as evidence. Overall, forensic anthropology is an essential discipline in the forensic community and criminal justice system.

Working closely with anthropologist, forensic odontologist are another key aspect in the forensic community. Like forensic anthropology, odontology has been around for hundreds of year and has proven to be a reliable forensic discipline. However, there is one sub-category of odontology which isn’t considered to be creditable. That is bite mark analysis. Bite mark analysis has been used in some cases which have lead to convictions, but overall it doesn’t have much credibility in the forensic community or criminal justice system. Therefore, bite mark analysis needs further research and procedures to make it more credible and reliable.   

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