Forensic Anthropology

The old saying that “Dead men do tell tales” was borne out in a remarkable French murder case in which a skeleton gave up sufficient of its secrets to identify the victim and trap a pair of murderers.

In 1889 police were called to a riverside location near Lyons where the badly decomposed body of a man had been discovered. Close by was a decayed wooden trunk bearing evidence that it had been sent to Lyons from Paris by railway.

Monsieur Goron, Chief of the Surete, thought the corpse might be that of a Paris bailiff, a man called Gouffe, who had been reported missing. One of Gouffe’s relatives was asked to view the remains, but as he was unable to make any identification the corpse was buried. Convinced that a crime had been committed, Boron obtained an exhumation order and three months after it was discovered the corpse was disinterred.

The post-mortem examination was carried out by Alexandre Lacassagne, Professor of Forensic Medicine at Lyons University. His attention was drawn to the condition of the right leg and ankle of the skeleton which suggested the muscles on that limb had been weaker than on the other. He thought this might have been due to disease and further examination showed that the right kneecap was deformed indicating inflammation of the joint during life. The weights of the bones in the right leg were also significantly lower than those of the left. Lacassagne’s opinion was that the dead man had probably suffered tubercular disease in that leg, and would certainly have walked with a limp.

Inquiries revealed that the missing bailiff had been treated for a knee complaint and did walk with a limp. This information, together with an impressive array of evidence, enabled the Professor to announce to officers of the Surety, “Gentlemen, I present M. Gouffë” A police investigation ensued which resulted in the arrest of Michel Eyraud, a shady business-man, and his mistress, Gabrielle Bompard, who were eventually convicted of murdering Gouffé to prevent his official inquiry into their business affairs.

When all that is left is a pile of bones, that’s when the police know to call in a forensic anthropologist.

Anthropology is the study of humans and it consists of several sub-fields:

  1. Physical anthropology – the study of the primate order, past and present, such as primate biology, skeletal biology, and human adaptation
  2. Cultural and linguistic anthropology – the study of the aspects of human society and language, past and present
  3. Archaeology – the study of past cultures via material remains and artefacts

 
To some degree, forensic anthropologists draw on each of these fields, but generally rely on knowledge from physical anthropology to apply their expertise to skeletal remains. According to the American Board of Forensic Anthropology, “Forensic anthropology is the application of the science of physical anthropology to the legal process. The identification of skeletal, badly decomposed, or otherwise unidentified human remains is important for both legal and humanitarian reasons. Forensic anthropologists apply standard scientific techniques developed in physical anthropology to identify human remains, and to assist in the detection of crime.” Given the emphasis on skeletons, there is a strong link between forensic anthropology and odontology.

Much of what occurs in forensic anthropology comes from the area of osteology, or the study of bones. They will also be familiar with human anatomy and how it varies in different populations. Some forensic anthropologists may also specialize in body decomposition and entomology (the study of insects) in order to help estimate the time of death. In recent years the task of the forensic anthropologist has become more complex and sophisticated. Forensic anthropologists assist medical and legal specialists to identify known or suspected human remains.

The science of forensic anthropology includes archaeological excavation; examination of hair, insects, plant materials and footprints; determination of elapsed time since death; facial reproduction; photographic superimposition; detection of anatomical variants; and analysis of past injury and medical treatment. However, in practice, forensic anthropologists primarily help to identify a deceased person based on the available evidence.

For example, when a skeleton found in a forest is brought to a morgue for examination, the first step is to determine whether the remains are human, animal, or inorganic material. If human, an anthropologist then attempts to estimate age at death, racial affiliation, sex, and stature of the decedent.

If the skeleton shows evidence of prolonged burial or is accompanied by coffin nails or arrow points, it usually represents an historic or prehistoric burial rather than a recent death. Construction crews frequently unearth such skeletons during road or housing excavations. After combining all of the evidence, the anthropologist determines the skeleton’s possible significance to medical and legal authorities.

Although the primary task of anthropologists is to establish the identity of a decedent, increasingly they provide expert opinion on the type and size of weapon/s used and the number of blows sustained by victims of violent crime. It should be noted, however, that forensic pathologists or related experts in forensic medicine determine the cause or manner of death, not the forensic anthropologist.

Perhaps the anthropologist’s most valuable skill is familiarity with subtle variations in the human skeleton. Although most adult skeletons have the same number of bones, no two skeletons are identical. Therefore, observations of patterns or unique skeletal traits frequently lead to positive identifications. The most frequently used method for identification is to compare before- and after-death dental photo images. If such photo images do not exist, or if they are unavailable, then old skeletal injuries or anatomical skeletal variants revealed in other photo images may provide the comparative evidence necessary to establish a positive identification.

Forensic anthropologists generally work with forensic pathologists, odontologists, and homicide investigators to point out evidence of foul play and assist with time of death estimates.

When a body has been found, particularly if there is little left but the skeleton the forensic anthropologist would be called in to help answer some key questions, such as:

  • What was the sex of the individual?
  • What is the individual’s racial affiliation?
  • What is the individual’s age?
  • What is the individual’s stature?
  • How long has the individual been dead?
  • Is there any evidence of trauma or foul play at or near the time of death?

 
Except for the skull, few persons are able to distinguish between human and animal bones with certainty. This is a matter for the expert anatomist, and where the remains are fragmentary he may require confirmation of human origin by applying the precipitin test. Once they have been verified as human, the bones of an unidentified skeleton are examined to establish the primary characteristics of the dead person – sex, age and height.

In general the skeleton provides ample evidence of its sex and age: the bones of the female, for example, are less robust than those of the male and the ridges which provide attachments for muscles and tendons are less prominent in the female. The pelvis, thigh-bones and skull are particularly noted for their sexual characteristics. The female pelvis, constructed to meet the needs of child-bearing, has several features – notably wider hips – which distinguish it from the male. Apart from general appearance, a number of measurements can be made of pelvic bones which help to establish sex. The difference in ratio between the lengths of the pubis and ischium (known as the ischium-pubis index) is commonly used for this purpose.

Age is determined by studying a number of skeletal features, principally the skull, teeth and centres of ossification. As the young human body develops from soon after conception until early adulthood, the growth of the bones is regulated by centres of ossification which gradually fill out and fuse together to give the bones shape and size. This process is established in a regular pattern which enables the skilled anatomist to give a reliable estimate of age to within one or two years. Examination of the growing ends of the bones epiphyses is especially relevant. The growth centres at the lower ends of the limb-bones permit the limbs to lengthen during childhood and thereby increase the height of the individual. These epiphyses are soft and cartilaginous during the growing period but gradually harden into solid bone and fuse with the main shaft of the bone as adulthood is reached. The head of the thigh-bone (femur) fuses between 18 and 20 years, and part of the hip during the 24th year. Consideration of the epiphyses in the long bones of a skeleton can therefore yield reliable information abut age up to 25 years. After that, age-determination depends on looking at the skull and other bones which show changes with age. As females mature quicker than males, the ageing aspects of the female skeleton are usually about a year ahead of the male.

Skulls have a number of important features which help to determine the age and sex of a skeleton. The appearance of the sutures or scams on top of the skull can give its approximate age. The vault of the cranium is made up of a number of flat bones which interlock at the edges by means of striations or sutures. In infants there are large gaps between these bones, which gradually close up after the age of 30. This fusing process occurs in a particular sequence beginning from the inside of the skull and working outwards. It is the state of these closures which allows age to be approximated; complete absence of closure indicates that the skeleton is less than 30 years old.

Age-determinations based on the state of the skull sutures are not exact, but in the absence of other information may be the only method of ageing human remains. This method was used by Professors John Glaister and J. C. Brash in 1935 to estimate the ages of two dismembered corpses which turned up in a ravine under the Carlisle to Edinburgh road. The experts estimated the age of each body to within a year of its actual age, which became known when they were identified as Dr Buck Ruxton’s murder victims.

The Ruxton case provided a number of challenges for the team of experts assembled from Glasgow and Edinburgh Universities, and the victims’ skulls featured prominently in their scientific investigation. Sex differences are notable in the skull, the main distinguishing feature being that the female skull is smaller than the male. The mastoid processes and orbital ridges are less prominent in the female, and the eye sockets and forehead are more rounded. Sex differences are also distinguishable in the pelvis, but the skull, being one of the human frame’s more durable parts, is especially significant in this respect. In the case of one of Ruxton’s victims Professor Brash was able to report, ‘Secondary sex characters are so well marked that I can express without hesitation the definite opinion that it is the skull of a female.’

A powerful piece of identification evidence in this case was achieved by the development of a new technique. A photographic negative enlarged to life size was made of a portrait of Ruxton’s wife, and this was superimposed on an X-ray of the skull. The result was a startling match, which Professor Glaister modestly described as ‘a close comparison’. The medical investigation of the Ruxton case won wide acclaim, and Glaister and Brash received an international award for their account of it.

The height of a person in life can also be determined by studying the long bones of the skeleton. An approximation of stature can be obtained by measuring from finger-tip to finger-tip of the out- stretched arms, the span of which is roughly equal to the body height. The idea that a fixed relationship exists between the lengths of the limbs, especially the legs, and the total length of the body was developed by Professor Mathieu Orfila. His calculations proved unreliable, but the method was improved first by Dr Etienne Rollet and then by Dr Karl Pearson. Pearson’s Formula, published in 1899, has now been discarded for the more accurate Dapertuis and Hadden formula.

Estimating the time interval since death can be extremely difficult. For the most part, such an estimate is based on the amount and condition of soft tissue, such as muscle, skin, and ligaments present, the preservation of the bones, extent of associated plant root growth, odour, and any carnivore and insect activity. However, many other variables must also be considered, including the temperature at the time of death, penetrating wounds, humidity/aridity, soil acidity, and water retention. The longer the time since death, the more difficult it is to determine the time interval since death.

Skulls have also featured as macabre exhibits in court-rooms. A juror fainted when the yellowed skull of Max Garvie was produced as part of the prosecution evidence against his wife Sheila and her lover Brian Tevendale, who were accused of murdering him. Garvie’s body, shot through the head, was found at St Cyrus in Scotland in l 968. This followed a stormy love-triangle which led to Sheila Garvie and Brian Tevendale electing to kill Max. The victim was shot dead while he lay asleep and his body was subsequently hidden. Garvie and Tevendale were found guilty and sentenced to life imprisonment.

The question of racial affiliation is difficult to answer because, although racial classification has some biological components, it is based primarily on social affiliation. Nevertheless, some anatomical details, especially in the face, often suggest the individual’s race. In particular, white individuals have narrower faces with high noses and prominent chins. Black individuals have wider nasal openings and subnasal grooves. American Indians and Asians have forward-projecting cheekbones and specialized dental features.

Some common terms used in anthropology associated with skeletons.

  • cartilage – a connective tissue, a strong stretchy type of tissue found in humans in the joints and other places such as the nose, throat and ears.
  • diaphysis – The shaft of a long bone.
  • epiphyses – A part of a long bone where bone growth occurs.
  • femur – the long bone in the upper part of the leg
  • flat bone – a bone that is thin in section, such as the skull bones.
  • humerus – the long bone in the upper half of your arm, between your shoulder and your elbow.
  • irregular bone – a bone with more than one shape in section, such as the vertebrae.
  • ligament – A band of fibrous tissue that connects bones or cartilages, serving to support and strengthen joints.
  • long bone – one of the elongate bones of the limbs, consisting of a shaft, or diaphysis, and two extremities, or epiphyses; the long bone establishes the height or length of the limb.
  • ossification – The formation of bone or of a bony substance, the conversion of fibrous tissue or of cartilage into bone or a bony substance.
  • radius – One of two bones which constitute the forearm.
  • sesamoid – Sesamoid bones, Sesamoid cartilages, small bones or cartilages formed in tendons, like the patella and pisiform in man
  • short bone – a bone that is of approximately equal dimension in all directions.
  • tendon – A fibrous, strong, connective tissue that connects muscle to bone.
  • tibia – the bone which can be felt at the front of the lower leg . The shinbone.
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