Forensic Anthropology

Forensic anthropology is a function of forensics and physical anthropology that specifically looks at skeletal remains in a forensic or crime detection setting to try 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, i.e. skeletal remains little could be done to determine the who, why and how of an individual's death. Though there are significant obstacles to overcome, especially regarding death modes that leave no trace on the skeleton forensic anthropology as a science has developed to such a degree that a great deal more knowledge can be gleaned from skeletal remains than ever before. A well trained forensic anthropologist can discover many things about the remains, identity, bone injury, disease and increasingly cause of death or time of death, an area that is increasingly asked of them 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 pool of very limited remaining evidence from a crime or unexplained death. The actual process is titled a trauma analysis. (Lovell, 1997) This work will briefly introduce the field of forensic anthropology, then briefly discuss identity formation and finally the work will detail a trauma assessment and explain 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 upon an accepted set of markers size differentiation and shapes of certain bone segments (Rhine, 1998, p. 77) (Ryan, 2002, p. 8) and then also by sampling for DNA, especially from core samples taken from large molars. They can also assist a forensic dental anthropologist or a dentist in discovering identity based on dental records. (Evans, 2004, p. 140) The forensic anthropologist if the skeletal remains are female can also determine if the individual had carried a child to full term or was possibly pregnant at the time of death. (Rhine, 1998, pp. 77-79) Yet, when identity is determined, suspected or waiting to be determined the forensic anthropologist is often asked to perform what is called a trauma assessment, to form an opinion regarding cause of death and time of death. This opinion is formed based on keen observation and an extensive knowledge of the skeleton and bone structure. (Schmitt, Cunha & Pinheiro, 2006, pp. 43-44)

…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)

Yet, 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 at doing so that in some cases, where minimal amounts of soft tissue are present, though not enough 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 with limited clues to go by can determine postmortem or perimortem trauma to the skeleton, say in cases where bodies are dismembered after they are dead to conceal a crime. Through the evidence of healing on the bones or bleeding around a skeletal wound or other possible clues the forensic anthropologist can help determine if a wound was received at the time of death or thereafter, or if 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 the injury to the bone can determine if the injury was blunt force trauma, sharp weapon or projectile and if the wound was suffered in life, death or at the point of death based on healing patterns and possibly pooling of blood around the bone injury, noting that this is a sign of trauma occurring just at death when the heart is still functioning to some degree. (Rhine, 1998, p. 210)

A forensic anthropologist can utilize skill to determine cause of death if 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 well as entrance and exit wounds of bullets, when they break or course through bones and of course sharp instrument trauma can also be evident on the skeleton. (Rhine, 1998, pp. 199-200) The patterns of blunt force trauma, sharp weapon or projectile trauma are all relatively clear, if one knows what to look for.

Blunt force trauma that result sin death is often associated with skull injuries, though it can be evident in cases where large bones are broken, say due to extreme kicking, dropping or having large objects forced on the body, such as the grill of a car. The trauma assessment in this case is looking for unclean breaks where the shape is indicative of blunt force. The injury usually projects in from the point of the break and creates a spider web effect on the skull, and a spiral or other blunt injury to other large bones. (Pickering & Bachman, 1996, p. 127) Blunt injury is usually indicated by bone breaks, without healing in areas where trauma occurred on the skeleton. Bone breaking is similar to what is found in common blunt force breaks, absent of murder but healing must be rules out to show the trauma as possible cause of death.

The injury, is however unlike what might be found in a case of a projectile trauma, where depending on the caliber of the weapon the entrance and exit wound shapes are usually clean but can show evidence of spider web breaks, but they are smaller more rapid breaks. For the most part the skeletal evidence of gunshot wounds are limited to skull wounds, where entrance and possibly exit wounds can be found, and occasionally the bullet if it does not penetrate through an exit wound. Though there are occasions where bullets have lodged in the spinal column. Projective injuries to other areas of the body are usually not evident on the bones, unless the bone is grazed by the bullet leaving a tell tale rounded striation, or a minute centralized fracture if there is a through and through wound from a bullet. (Pickering & Bachman, 1996) (Langley, May 2007) The bullet wound exit and entrance show specific markings, with sharp margins and multiple radiating fracture marks. (Langley, May 2007) Determining the caliber and type of the weapon, though not exact, can be done to some degree by measuring the size of entrance, or if they exist exit wounds and also by locating existing bullets found in skeleton. Yet, this is only possible in limited cases. Entrance wounds also often show convex beveling at the site and on the bone. (Quatrehomme & Iscan, 1998) Additionally, exit wounds are usually larger than entrance wounds as they are indicative of lost force in the bullet trajectory. (Kimmerle & Baraybar, 2008, p. 257-261) It is also important to note that if a gun shot wound was not immediately fatal the bones go through a predetermined system of healing that can be seen on skeletal wounds and can determine the age of the wound. This assessment would be critical if a skeletal remain case where bone healing at different stages had occurred from any injury evident on the skeleton. (Barbian & Sledzik, March 2008) Laslty, skeletal disease indications must be ruled out as these are most likely to be evident in non-traumatic deaths and can mimic traumatic injury, i.e. such as in cases of cancerous or other lesions caused by disease. (Ortner, 2008)

Logically, sharp object injuries to the skeleton are also uncommon, because death caused by such a weapon as a knife often only needs to penetrate the soft tissue of the body to produce fatality, yet where such injuries are found they are indicative of sharp object striations. Cut marks on bones can be varied depending a great deal on the area of the injury as well as the type and size of the knife, tool mark studies are currently refining the science of forensic anthropology to assist scientists in helping to determine the weapon or…