Forensic Anthropology: Skeletal Trauma Analysis Explained

Introduction to Forensic Anthropology

Forensic anthropology is a branch of forensics and physical anthropology that specifically examines skeletal remains in a forensic or crime-detection setting in order to make inferences about those remains (Ryan, 2002, p. 15). It was once an accepted fact that once a body had decomposed to a certain degree — that is, to skeletal remains — little could be done to determine the who, why, and how of an individual's death. Though significant obstacles remain, especially regarding modes of death that leave no trace on the skeleton, forensic anthropology as a science has developed to such a degree that far more knowledge can be gleaned from skeletal remains than ever before.

A well-trained forensic anthropologist can discover many things from remains: identity, bone injury, disease, and increasingly cause of death or time of death — an area that is asked of them more and more due to new science and legal demands for solving older crimes. In short, a forensic anthropologist can be an integral expert in cases where skeletal remains are among a very limited pool of remaining evidence from a crime or unexplained death. The actual process is titled a trauma analysis (Lovell, 1997). This paper briefly introduces the field of forensic anthropology, then discusses identity formation, and finally details a trauma assessment and explains the major categories of trauma as they are manifest on the human skeleton.

A forensic anthropologist can help determine identity by first assessing the gender, size, stature, and sometimes race of the individual, based on an accepted set of markers, size differentiations, and shapes of certain bone segments (Rhine, 1998, p. 77; Ryan, 2002, p. 8). They can also assist by sampling for DNA, especially from core samples taken from large molars, and can help a forensic dental anthropologist or dentist discover identity based on dental records (Evans, 2004, p. 140). If the skeletal remains are female, the forensic anthropologist can also determine whether the individual had carried a child to full term or was possibly pregnant at the time of death (Rhine, 1998, pp. 77–79).

Establishing Identity from Skeletal Remains

Once identity is determined, suspected, or pending confirmation, the forensic anthropologist is often asked to perform a trauma assessment in order to form an opinion regarding cause of death and time of death. This opinion is formed through keen observation and an extensive knowledge of the skeleton and bone structure (Schmitt, Cunha, & Pinheiro, 2006, pp. 43–44).

As one account of early forensic investigation notes, "murder investigators found themselves desperate for clues as to time of death, and not just for evidence of guilt at trial. Knowing when a victim died could speed the earliest stages of an inquest by ruling out suspects with confirmed alibis and focusing scrutiny on those who did not. The postmortem interval, or time since death, proved even more critical in cases where a corpse turned up decomposed beyond recognition. Even an approximate time of death gave investigators a framework in which to connect the remains to a suspicious disappearance" (Sachs, 2001, p. 5).

Trauma Analysis and Time of Death

Time of death will likely remain an important but controversial scientific application for some time. The current trend in forensics is to develop a set of standards regarding skeletal evidence of cause of death. Additionally, the forensic anthropology field has become so adept in this area that in some cases, where minimal amounts of soft tissue are present but insufficient to determine cause of death, a body is further skeletonized so that the skeletal remains can assist in the determination of trauma (Rhine, 1998, pp. 199–206).

The forensic anthropologist, working with limited clues, can determine postmortem or perimortem trauma to the skeleton — for example, in cases where bodies are dismembered after death to conceal a crime. Through evidence of healing on the bones, bleeding around a skeletal wound, or other possible indicators, the forensic anthropologist can help determine whether a wound was received at the time of death or thereafter, or whether skeletal degradation was the result of natural or environmental decay (Evans, 2004, p. 9; "Skeleton Sleuths Work against," 2002, p. A13). The patterns and shapes of trauma to the bone often help the forensic anthropologist determine the nature of the perimortem wound. The shape of an injury to the bone can indicate whether it was blunt force trauma, a sharp weapon, or a projectile, and whether the wound was suffered in life, at death, or after death — based on healing patterns and possibly the pooling of blood around the bone injury. Such pooling is a sign of trauma occurring at or near the moment of death, when the heart is still functioning to some degree (Rhine, 1998, p. 210).

A forensic anthropologist can utilize these skills to determine cause of death when the death trauma caused physical injury to the bones — such as in cases where strangulation occurred and the hyoid bone was fractured. Blunt force trauma injuries, especially to the skull, are also often evident in skeletal remains, as are entrance and exit wounds of bullets when they break through or course through bones. Sharp instrument trauma can likewise be evident on the skeleton (Rhine, 1998, pp. 199–200). The patterns of blunt force trauma, sharp weapon trauma, and projectile trauma are all relatively distinct, if one knows what to look for.

Conclusion

The new emphasis in law enforcement and forensics on solving old murders and identifying victims of traumatic death has made the science of forensic anthropology much more important. Years of work in forensics and anthropology are compiled to train and assist in this process. The forensic anthropologist is frequently asked to form an opinion on cause of death and even time of death, in addition to the many other pieces of information that can be gleaned from skeletal remains. Forensic anthropologists do this — when the evidence permits — through an extensive knowledge of the skeleton and how it responds when trauma is inflicted upon it.