Forensic anthropology

Forensic Anthropology



  Anthropology is a vast field of study, and so is archaeology, both of which can be applied forensic sciences. Often divided into two areas, anthropology is either: the science that deals with the origins, cultural development, characteristics, social customs and beliefs of humankind (cultural anthropology) and the study of humanity's similarity to and divergence from other animals (physical anthropology). Cultural anthropology has never really had much of a relationship with the law, whereas physical anthropology has always been a recognized area of forensic expertise as least since 1850.


  It's generally agreed that forensic anthropology is the application of the science of physical anthropology to the identification of skeletal, badly decomposed, or otherwise unidentified human remains.


Forensic anthropology apply standard scientific techniques developed in physical anthropology to identify human remains, and to assist in the detection of crime.


  Forensic anthropologists frequently work in conjunction with forensic pathologists odontologists, and homicide investigators to identify a decedent, discover evidence of foul play, and/or the postmortem interval. In addition to assisting in locating and recovering suspicious remains, forensic anthropologists work to suggest the age, sex, ancestry, stature, and unique features of a decedent from the skeleton.


  Related specialties include forensic archeology (especially the protocols of excavation), forensic entomology (especially the study of insect larvae), and forensic botany (the use of pertinent plant evidence at a crime scene). Anything undiscovered for 50 years or more is usually arbitrarily defined as "archeological," but there are many who don't agree with this, or recognize things "archeological" in other ways.


  The study of insects, or entomology, represents a more unified approach since it deals with fairly established principles from anatomy, morphology, and physiology. Most of the relevant specialties are covered in this lecture, but the initial discussion is on anthropology proper. Expert qualifications include possessing an earned Doctoral degree in Anthropology with an emphasis in Physical Anthropology.


  Forensic anthropologists are "bone detectives" who help police solve complex cases involving unidentified human remains. The techniques which physical anthropologists use to discover information about early humans from their skeletons are also used to discover the identity of the victims of accidents, fires, plane crashes, war, or crimes such as murder.


  A forensic anthropologist can tell a lot about a person from bones: They can determine if the person was a male or female. This is determined by studying the pelvis, base of the skull, the forehead, and the jaw. Males usually have a more prominent brow ridge, eyesockets, and jaw. Women have a wider pelvis. They are able to approximate how old the person was by examining the joints, bones, and teeth. A child’s skull has more separation between the bone plates.


  The smoother the skull, the older the person. The examination of wrist development for children under thirteen is another reliable method of determining age. For most bones, the estimation of age works best if the victim is under age 30. Forensic scientists use formulas to determine height based on the length of leg and arm bones. The longest bone, the femur, is best for this, but estimations can also be made from the metacarpals in the hand.


  They are able to tell the person’s weight by the wear on the bones at certain points. They may be able to identify the racial group to which the person belongs by examining the width and height of the nose. Facial or head hair, when found with the skeleton, can also help determine race. Caucasian nose holes are triangular, Negroid's square, and Mongoloid's diamond-shaped.


  Negroid femur bones are also straighter than other racial groups. They may guess what occupation the person had. For example, if the person played an instrument such as a flute or clarinet, the teeth and bones around the mouth will be affected. A carpenter’s or a roofer’s teeth might be clipped in front where he held nails in his mouth. They can determine a person’s shape. Ridges where muscle was attached to the bone show the person’s physique.


  They can tell whether the person was right or left-handed. There would be more muscle attachment on the bones on the dominant side. They are able to determine if he was ever injured or fractured a bone during his lifetime. Detected bone injuries can be compared with a person’s medical X-rays to confirm identity. They also can determine if the person died violently. This is determined by looking for signs of trauma. These include stab marks, marks on the skull, broken bones, and bullets or pellets in or near the body.


  If the person was strangled, the bone from the throat (the hyoid bone) could be fractured. They are able to approximate when the individual died. The amount of soft tissue that is still present is the key to determining time of death, although weathering cracks on bones (from winter) or animal/rodent bites can also be used.


  Females lose one pound of tissue a day during decomposition; males three pounds a day. Acidic soil accelerates decomposition; alkaline soil retards it. Most of these are class characteristics (such as age, sex, race, and height), but some are individual characteristics (such as trauma). Courts would probably never rely independently on forensic anthropological identification.


  It would most likely be used to corroborate other evidence or supplement the testimony of other experts. Lawyers frequently stipulate forensic anthropological evidence because much of it may be gruesome and prejudicial to the jury. Bringing bones into the courtroom as demonstrative evidence, for example, is somewhat controversial. Experts are typically allowed to render opinions in wide areas of allied disciplines as long as they are well-schooled in those areas.


  Police may also turn to anthropologists for facial reconstruction, recreating a face from the skeleton to help them identify the deceased. When asked to create a reconstruction, anthropologists first determine as much as possible from the skeleton, which includes such information as age, race and sex. Then, using tissue thickness sample charts, the artist glues pieces of plastic which look like pencil erasers of various lengths to the skull or a plaster copy, at eighteen to twenty-six key points.


  These pegs are cut to the thickness specified by the chart. Using the pegs as a guide, the artist fills in the areas with modeling clay. The eyes are the hardest to do as they are almost entirely tissue. Other difficult areas include the ears, because their size is difficult to determine. It is also very difficult to reconstruct the lower parts of the nose and the lips. Computer-assisted facial reconstruction software (FACES) also exists.