A skeleton can be a mine of information for specialists in forensic anthropology, a expert told a Dublin audience last night. Dick Ahlstromreports
A surprising amount of personal detail can be learned from long- buried bones. The trick is knowing how to read the signs, according to an expert in the practice.
Prof Sue Black, a forensic anthropologist from Scotland, last night delivered a thought-provoking lecture on the power of this science as a guest of University College Dublin's department of human anatomy and physiology. The deputy state pathologist, Dr Marie Cassidy, introduced her, and delegates included members of the Garda Technical Bureau, the Forensic Science Laboratory and the Natural History Museum.
The goal of forensic anthropology is to establish identity despite having little more than skeletal remains, she told The Irish Times ahead of the lecture. "We are not there to establish cause of death or if a crime was committed. We are there to establish who this is. It is all about trying to get evidence from the bones and bringing the person back to life in a metaphorical sense."
It takes a bit of sorting to unravel the various skills in forensic anthropology, forensic science and pathology, she acknowledges. When human remains are found the pathologist confirms how the person met their end and the forensic scientist collects evidence from the scene and the remains for use in any subsequent court case.
The forensic anthropologist is called in, however, when there are no clues as to who the person was. "We only get called in when the police have nowhere else to go," says Black, who is professor of anatomy and forensic anthropology in the School of Life Sciences at the University of Dundee.
In British law, if the remains are older than 70 years they are classed as archaeological, but they become a forensic case if less than this, she explains. "It depends upon the site where the remains were found and this will decide if it is a forensic situation," Black says.
Usually there are clues to help identification, for example car ownership could point the way if an unidentifiable body is found in a burnt-out car. The body might be carrying identification or credit cards, again providing a way to confirm identity.
The skills of the forensic anthropologist come into their own, however, when there are no clues left behind. "One of the worst case scenarios for the police is having an unidentifiable body," she says.
Buried bones of indeterminate age could be anything, she explains, so the first thing to establish is whether they are human or animal. "We are often called in and immediately tell them, forget it, it is a cow. You would be surprised how many animal bones are brought to the police as human." If they are human, the next call is how many humans are represented among the bones found, one or a number. Next comes the "biological identity of the person", for example whether male or female. "If you can do that you can eliminate 50 per cent of all the missing persons cases on the books," she says.
Age can also be determined from the bones alone, she notes. "All of the time we are trying to narrow it down to match the missing persons list." Estimated height when living is next and also race or ethnicity. The key clues of age, sex, race and height considerably reduce the number of possible matches associated with a missing person.
If DNA is available from the remains this can be compared with samples given by relatives of missing persons. Dental records might also be available to tighten the search focus, she says.
The remains will also indicate handedness, right or left, she says, and if some tissue is available it might be possible to take fingerprints or analyse lymph nodes. Tattoo dyes accumulate in the lymph glands and analysis can tell whether the person had tattoos on the upper or lower body. It is an effort to discover "anything about you that says you are different" that will aid identification, she adds.
All of these personal details can be derived through the skills of the forensic anthropologist. "There really are no fancy pieces of equipment. It gets down to experience," she says.
Yet modern technology is coming to the fore, particularly in the area of computer reconstructions of a face. The personal details about sex, age, race and height can be blended with computer simulations of a face superimposed over the skull. Laser scans of the skull provide a template upon which to build up a face.