What Do Forensic Anthropologists and Detectives Have in Common?
Forensic anthropology is a special sub-field of physical anthropology (the study of human remains) that involves applying skeletal analysis and techniques in archaeology to solving criminal cases. When human remains or a suspected burial are found, forensic anthropologists are called upon to gather information from the bones and their recovery context to determine who died, how they died, and how long ago they died. Forensic anthropologists specialize in analyzing hard tissues such as bones. With their training in archaeology, they are also knowledgeable about excavating buried remains and meticulously recording the evidence.
Reading a Skeleton
A forensic anthropologist can read the evidence in a skeleton like you read a book. The techniques they use to answer questions in criminal cases can be applied to skeletons of any age, modern or ancient. The stages of growth and development in bones and teeth provide information about whether the remains represent a child or adult. The shape of pelvic bones provides the best evidence for the sex of the person. Abnormal changes in the shape, size and density of bones can indicate disease or trauma. Bones marked by perimortem injuries, such as unhealed fractures, bullet holes, or cuts, can reveal cause of death. The trained anthropologist is also able to identify skeletal clues of ancestry. Even certain activities, diet, and ways of life are reflected in bones and teeth.
Analyzing Human Remains
Anthropologists at the Smithsonian’s National Museum of Natural History have been called upon to analyze human remains for over a century. The remains may represent victims of violence or natural disasters. In these cases Smithsonian anthropologists work with the FBI, State Department, and other law enforcement agencies to identify the individuals and solve crimes. They also conduct research on historic and prehistoric human remains to learn more about people from the past. As Smithsonian forensic anthropologist Kari Bruwelheide says, "The bones are like a time capsule."
Smithsonian anthropologist Dr. Douglas Owsley, examining a skeleton from historic Jamestown, discovered evidence of chops to the skull from an axe or other sharp bladed, implement. Knife cuts were also observed on the bone. Along with other information such as biological indicators and discovery location of the remains, Dr. Owsley concluded that a 14-year-old girl had been cannibalized after she died. His discovery supported other historic data that the colonists of Jamestown suffered severe starvation during the harsh winter of 1609-1610.
Techniques: Leaving No Bone Unturned
Anthropologists at the National Museum of Natural History use a variety of techniques to analyze human remains and record their observations. For example, the bones are typically photographed and X-rayed. Some remains may undergo CT scanning or be examined with high-powered microscopes. These techniques provide detailed information about remains without altering them while providing a visual record. DNA analysis may be used to help establish identity. This type of testing is most often used in modern forensic case work, but mitochondrial DNA in bones and teeth can be used to confirm relationships of old remains with deceased or living descendants. Other chemical analyses, such as those involving isotopes, can provide information about the age of bones and a person’s diet.
The data gathered is studied and combined to draw conclusions about the deceased individual. For a modern case, photos of the skull may be superimposed on photos of missing people to look for consistencies between the bone and fleshed form. Even in cases where no photos exist, the face can be reconstructed based on the underlying bone structure and known standards of facial tissue thicknesses. For example, using facial reconstruction, Smithsonian forensic anthropologist Dr. David Hunt was able to bring about correct identification of the remains of a child found near Las Vegas. Owsley and Bruwelheide were able to help rebuild the likeness of the girl from Jamestown.
Collections of Bones
Comparing found remains to other human skeletons is essential for many analyses. The National Museum of Natural History has one of the world's largest Biological Anthropology collections, with over 30,000 sets of human remains representing populations from around the world. Many of the skeletons have associated age, sex, ancestry, and cause of death data. Individual remains with known biological information are especially valuable references. Forensic anthropologists have used these skeletons to develop standards for determining sex, age and ancestry in unknown remains. The bones and teeth are also used as comparative materials in cases where interpretation of certain features is difficult. They are also used to train students who are the next generation of biological anthropologists. Skeletal reference series may also be used to document trends in health and population structures over time. Smithsonian Curator Dr. Douglas Ubelaker, looking at a range of skulls from 16th-20th century Spain and Portugal, found that women's faces got larger over time.
Reconstructing the Past
The study of historic human remains by biological anthropologists at the Smithsonian has led to discoveries that are changing our view of the past and how we investigate it. The work of Dr. Owsley and Kari Bruwelheide has helped create a better picture of how people lived and died in colonial America. For example, even a wealthy woman, the wife of the governor of Maryland's first English colony, St. Mary's City, suffered from limited medical care for a fractured thigh bone. The sorts of treatments that would be used today (traction and screws), were not options at the time. Available treatments, such as medicine containing arsenic, may have made conditions worse. Chemical testing of this woman's preserved hair show ingestion of this toxin with increasing dosage closer to death.
Whether used to better understand modern or historic remains, the tools and techniques of forensic anthropology give the living a window into the lives of the dead.