By Avril Eyewu-Edero
In 2012, when I worked at the coroner’s office in Lagos state as a forensic investigator, we got a notification to process a scene that two skeletons were found somewhere in Lagos.
I remember getting to the scene which was very interesting and seeing two separate skeletons in different positions inside the room. After processing the scene, we moved the remains to the coroner’s office for an examination, this was my first experience working with Pathologists to explore this exciting aspect of forensic science, Anthropology.
Forensic Anthropology is the aspect of forensics that deals with the examination of human skeletal remains to help ascertain the identity of the victim (sex, age, race, stature), interpret any trauma to the remain (gunshot wood, stab wound, health condition, etc) and to give an estimated time of death for criminal proceedings or identification of missing persons.
A forensic anthropologist would usually present their evidence about the identity and any trauma or injury found on a skeleton in the court. Their evidence can also help the court understand the circumstances of death.
A few years ago, I was part of a team that had to carry out autopsy and DNA identification of some remains in the Northern part of Nigeria. These remains were all skeletons and we had to examine and note all the injuries on each remain which gave a clearer understanding of the circumstance of their death which was different from the circumstances originally assumed. Cases like this are one of the reasons forensic science is useful.
The first and most important step in the examination of the skeleton in a criminal case is to ascertain if the remains are human or a non-human animal. Because all mammals share a generalized skeletal composition and have bones located in similar positions, it could lead to questions.
The structure of the bones and their relationship in the skeletal frame differs between animals. The anthropologist can address this by examining the shape, structure, and size of the bone to determine if it is human. This would be particularly useful in Nigeria in cases of suspected ritual killing. A defendant that is accused of ritual killing because some bones where found in his/her house can be exonerated if an anthropologist can carry out this analysis and determine if the bone found is human or not.
It Is also important that the anthropologist determines how many victims are present if they find bones at a crime scene, this will help determine if it will be a single or multiple homicide charges. This can be determined by carefully analyzing the bones for duplicate or multiple body parts of the same structure, for example, if two right femora (thigh bones) are found in a scene, that explains that the crime involved more than one victim.
In the identification of the skeleton, there are some common markers that aid identification. In identifying the sex of a skeleton, there are some specific features that differentiate a male from a female. The most prominent difference between a male and female skeleton is that the pelvic bone in a female is wider than that of a male because women are created and adapted for pregnancy. The pelvic bone in women is also lower than the pelvic of a male skeleton.
To determine the age at death of the deceased, anthropologists look at changes in the degree and location of bone growth and dental formation and eruption in young people. As human progress in age, soft cartilages are replaced by hard bones at different centers of growth at known rates, anthropologists use the pattern of growth to estimate the age of an individual.
To determine the size of the deceased, anthologist measure the arm and leg bones and use a formula that checks variation by sex and ancestry group to help determine the height range. This is particularly useful in missing person cases when the remains are discovered.
Anthropologists use different methods to analyze skeletons and record their observations, through CT scanning, photograph, microscopic examination, and x-raying the bones to aid identification. This is also useful in cases of missing persons as a skull could be superimposed onto a picture of a missing person to check for matches between the bone structures and fleshed form.
In the case of an unknown victim, a face can be reconstructed using the underlying bone structure of the skeleton and known standards of the thickness of known facial tissues. These reconstructions are usually almost precise and have helped a lot of families in other countries identify their missing loved ones and finally get the closure they deserve.
Just like every forensic technique and their usefulness in the criminal justice system, forensic anthropology offers answers to cases beyond a reasonable doubt.
As we continue to propagate for a better evidence-based criminal justice system in Nigeria, anthropologists in Nigeria should start expanding their scope and learn about forensic science and how they can incorporate their knowledge to aid the law.