Physical anthropology focused on the study of the human skeletal population in terms of growth, nutritional assessment, paleo demography (study of demographic features of past populations) and the general descriptive analysis of skeletal population. Many of physical anthropology’s reconstruction and archaeological excavation techniques are used to collect and analyse human remains as legal evidence. The process of determination of biological sex, age, stature and race of an individual through their skeleton was established long before. ‘Forensic’ anthropology grew out of physical anthropology as a sub-discipline in the 20th century. Various age estimation methods such as the dental eruption sequence and epiphyseal closure in children which are still used today just like research methods on race assessment and sex determination through skeletal remains, could be explained to medico-legal officials. Forensic anthropology is used not only for identification purposes but also for conditions and cause of death. However, forensic anthropologists also work on identification and cases involving living people. Experts use their anthropological specialisation in determining the age of juvenile perpetrators and individuals who have been caught on surveillance systems.
Legal Context of Forensic Anthropology
Forensic anthropologists are used in court rooms as experts to provide evidence regarding the remains that have been found and the possible theories that resulted in the killing of certain individuals. In the Indian context, Sections 45 and 46 of the Evidence Act, 1872 are to be taken into account. As per Section 45 of Indian Evidence Act, 1872 – “When the Court has to form and opinion upon a point of foreign law or of science or art, or as to identity of handwriting or finger impressions, the opinions upon that point of persons especially skilled in such foreign law, science or art, or in questions as to identity of handwriting or finger impressions are relevant facts. Such persons are called experts.” Further as per Section 46 of Indian Evidence Act, 1872 – “it is stated that facts, not otherwise relevant, are relevant if they support or are inconsistent with the opinions of experts, when such opinions are relevant.” An analysis of Section 45 and 46 determine that with regard to any scientific observation, the court will rely on the knowledge of people who have technical expertise in the area.
Use of Forensic Anthropology
Forensic anthropology is a vital part of laboratories around the world that engage in forensic science or law enforcement. It is used in cases of mass murders, mass disasters, cases of mass burials and military casualties involving many skeletal remains. Forensic anthropology is used to establish identity of the human remains, the circumstances and cause of death of the individual. In cases involving death, when family members and friends may not be able to view the body due to the emotional and mental scarring that it could lead to, in cases that involve decapitation or dismemberment of any type, forensic anthropology plays a part.
Forensic anthropologists work in association with other forensic science and medical experts such as forensic odontologist, archaeologists, pathologists and entomologists to identify the remains, and help the law enforcement agencies and legal authorities. It has also encompassed the use of facial image analysis in investigations regarding human trafficking, burglars recorded by surveillance cameras and witnesses along with other cases such as identification of people involved in immigration problems and mix up of children in hospital nurseries.
Taphonomy relates to the interpretation of all the events that have occurred from death to discovery of the remains which will affect the remains. It is a distinct sub-field of forensic anthropology which interpret what has happened to the remains between death and discovery. It takes into account the surroundings of the remains, such as tree roots, chewing by animals and natural post mortem erosion, and whether they have affected the remains in such a way as to mimic trauma. It allows the anthropologist to differ between foul play and naturally occurring post mortem processes
Steps in identification
Skeletons and other parts reach the laboratory in a disintegrated and fractured state. There are a few steps that are required in that case to start the identification process. Step one involves answering if the bones are human in nature or not. After that, the number of human skeletons needs to be established. Although this may sound easy, it becomes tougher due to the similarity between animal bones and bones of sub-adults. Further identification becomes difficult due to the possibility of fragmentation of bones, signs of diseases that can affect growth and may affect the identification of age or sex. Step two involves the estimation of group traits such as age, biological sex, stature and race which help limit the range of persons. Step three involves the identification of individual traits.
Method of identification
Human vs. Animal: Sometimes the simplest task of identifying evidence as human or non-human can be fraught with difficulty. Burnt drywall, plastic, wood and other materials can often resemble bone. Fire can lead to wide-ranging bone fragmentation, therefore the distinction between the remains of a human fire victim and the other residue from the building. Forensic anthropologist examines subtle morphological expressions that allow in determining the nature of the residue.
Identification of Group Traits: The identification of group traits takes place through determining the race, sex, age and stature of the human.
1) Race: Due to the varied interpretation of the word race in physical anthropology, forensic anthropologists can provide information to law enforcement the likely geographic ancestry of the individual through an assessment of morphological traits that are available. The skull remains the most reliable part of the skeleton from which the race of an individual can be determined. Earlier, classification of race was divided into three broad groups of Caucasoid, Mongoloid and Negroid. Interracial mixing has and will continue to change the characteristics of not only the skull but other skeletal remains, thereby making it tougher for forensic anthropologists to determine race.2)Sex: In determining the biological sex of the human remains, pelvis is the most beneficial bone. Forensic Anthropologists measure the width of the pubic bone and assess the pubic arch to determine the sex of the human remains.3)Age: Age has always been the toughest indicator especially with regard to adults. Teeth are used fairly commonly for skeletons below the age of twenty-one due to the formation and eruption of teeth. The aging process in the early years can be determined by ossification of the centres, fusion of the bones and the progress of the epiphyseal closure. The rib is a useful bone in which a rib phasing technique allows the anthropologist to judge the process of aging.4)Stature: Stature is determined through the use of regression formulae which have been derived from known samples of age, sex, race and stature which are reasonably accurate.
Identification of the Specific Individual
1) Identity impossible: Due to reasons such as differences in the ante mortem and post mortem evidence, the identity cannot be established and is therefore impossible to determine.2)Indeterminate: There are certain general similarities such as baldness, lip thickness and shape, round faces and ear configuration, further population specific features such as nasal width, nasal profile, eyelid folds are also included as common characteristics which make identification indeterminate if there is no unique feature to set them apart as a definite person.3) Possible: The identification of the individual is matched on the basis of the group traits (age, sex, stature, race) and will undergo further rigorous testing which includes the use of skull-photograph superimposition and photographic comparison. 4)Positive: The identification of the individual is completely accurate without any contradiction taking place. Unique factors of individualization, congenital abnormalities, also known as birth defects (such as cleft palates), along with a match of dental records, if possible, match ante mortem and post mortem which allow the forensic anthropologists to identify the individual.
Techniques in Identification
To identify specific individuals, there are a few tests or techniques which are undertaken such as DNA testing, dental comparison, facial reproduction, skull photograph superimposition and photographic comparison DNA testing: DNA testing allows the use of small cell samples to determine individuals due to the characteristics of their unique DNA. DNA match their identity by comparing the post mortem DNA sample with ante mortem DNA sample. Dental comparison: With the help of dental records in ante mortem and post mortem help in confirming the identity of the individual. Facial reproduction: Artist with the help of a forensic anthropologist, determines what a person looked like from their skull. This technique is primarily used a last resort to produce a likeness of an individual to make a positive identification. The problem that arises with facial reproduction is, either the inexperience of the artist or the lack of scientific basis by assuming features which cannot be known by looking at a skull such as hair colour, length and form, dimples, scars, facial hair and fat on the face. Skull photograph superimposition: Skull photograph superimposition is a technique that has been used even in the 1880s when portraits of people were superimposed on skulls. Nowadays, computers allow forensic anthropologists to take into account the skulls three dimensional character while putting a photograph on top of it. However, once again there is a problem of precise land-marking the bony features of the skull without taking into consideration the effect of age and facial fat etc. Photographic comparison: This is used to identify living persons and compares photographs of an individual to try and determine identity. It is usually difficult if there are no individual unique characteristics that can be noted.
Aman Kumar Rastogi JGLS’14
Edited by –
Poulomi Bhadra, Prakriti Kapoor