Forensic Anthropologists - Application

Application

Within forensic anthropology are many disciplines of specialists; one of which is osteology. For basic identification purposes in forensic anthropology, osteological analysis of age, stature, ancestry, and sex of the skeletal remains are first determined. The investigator may find evidence regarding cause and manner of death; however, when flesh is still found on the bone, the stage of decomposition is noted and time since death may be more effectively narrowed. When identifying age and stature, a range is given, rather than a finite number. Because an individual's nutrition can affect bone structure, a physiological age is estimated based on the state of the bones. Since lifestyle plays a large role in the growth and decay of bones, it is not possible in many cases to unequivocally determine bone age. Therefore the age is noted as a probable range. A range is also applied to stature based on the length of long bones, applied to a specific mathematical equation. Different equations have been developed for the sexes and for several geographic populations based on common phenotypic features or metric trends. Estimated stature is given in a range of centimeters.

Osteological traits on the pelvis and the cranium can provide clues as to ancestry and gender. Features such as the shape of the supraorbital ridge, incisors, mental protuberance, mastoid process, among other cranial features are fundamental to the identification of ancestry and gender for the skeletal remains. The pelvis may play a role in the differentiation between male and female. Features such as the pubic symphysis or the ishchio-pubic index can help to identify sex. Theoretically, it is cranial traits that help most with identifying the ancestry of the individual; however, the identification of ancestry is not limited to the cranium. Analysis of age, stature, and sex are not limited to these procedures as forensic anthropologists use a multi-factorial approach to provide these results.

Forensic anthropologist Dr William Rodriguez testified for the prosecution in the trial of David Westerfield for the murder of Danielle van Dam in San Diego, California, in 2002. She went missing on the night of February 1, and her body was found on February 27. He hadn’t examined the body himself, but based on many photographs and reports (including the autopsy report), he concluded it was in an advanced stage of mummification. Factoring in the weather data, he estimated a post-mortem interval of approximately 4 to 6 weeks - so between January 16 and 30, which is impossible, and he had to be pressed by the prosecution to extend his time frame to within the bounds of possibility. Yet the autopsy report mentions only superficial mummification, and this was confirmed by the entomologists. The other likely reason for his over-estimate is that estimating the post-mortem interval of someone so recently deceased, did not feature in his detailed work experience.