The Identification of Human Skeletal Remains

A. KEITH MANT Lecturer i n Forensic Medicine, Guy's Hospital, London, England

The detailed examination of human skeletal remains is a highly specialised branch of anatomy, and although a pathologist in certain cases may feel fully justified in giving an opinion, in many the services of a skilled anatomist are essential.

I t would be out of place in this paper to attempt to describe in detail the specific indices and techniques employed by anatomists in anything but the most general terms. Not only would it take more than a day to elaborate all these techniques, but also as all cases where difficulty arises should be passed to the anatomist, I shall confine myself to what the anatomist can discover from the material which may be available.

When bones, or fragments of bones, are found the first question to be answered is "Are these bones human or animal ? " In many cases characteristic human bones are found which can leave no doubt in the mind of the doctor who examines them that they are in fact human. Mistakes, however, are still occasionally made, and it is not very long ago when a bear's paw was thought to be human, and this initiated considerable and unrewarding police activity which was finally halted after the Museum of Natural History had identified the origin of the bones.

When only small fragments of bones are found the examination is at once highly specialised. To quote an actual case of this kind : some years ago a collection of brittle bony fragments were found on a rubbish dump. As there was something unusual about the appearance of the fragments, the police were anxious to ascertain whether they were human or animal. The late Professor Willis of Guy's Hospital, and Editor of Gray's Anatomy, examined these frag- ments and at once stated that they were human, and located their anatomical sites. The fragments were clearly cremated remains which had not been pulverised, but how and why they came to be on the dump still remains a mystery.

Once it is ascertained that the bones are human, the next question which arises is "how long has the person been dead ? " If the person died more than 70 years ago the police are unlikely to have further interest, a t least from a criminal point of view. In dating the age of skeletal remains it is essential not only to examine the bones but also the locus where they were discovered. This problem is not infrequent at the present time in the London area where several Plague pits are being unearthed during excavations. In some cases the remains are only discovered when they have been moved to a dumping ground many miles from the site of the excavations. In cases of this nature assorted bones from many bodies are usually produced. These bones are clearly of great age, and should offer no real difficulty.

Portions of bones from victims of bombing raids during the last War clearly require more careful consideration, but reference to the local records will often be of assistance. Reference to the local records also frequently helps when only one or two bodies of great age are discovered. In cases where there is no supporting documentary assistance, the dating of skeletal remains is largely a matter of personal experience.

When skeletal remains of recent origin are discovered the whole problem becomes more complex, and the time which has elapsed since death, the cause of death, and the identification of the deceased, become matters of importance. If the body has lain in the open it is unlikely that the skeleton will be complete. A wide variety of animals, such as rats, foxes and dogs, may partly destroy and

even carry off portions of the body, which may never be recovered even after an exhaustive search. The more complete the skeleton the easier the task of the pathologist or anatomist who is to examine it.

The estimated time of death must necessarily be a very wide one. I t rests largely upon personal experience after detailed study of the bones and the environment in which the body was lying. Previous knowledge of the rate of decomposition of bodies in the same neighbourhood, where the time of dis- appearance is known, is invaluable in making assessments of this nature.

The cause of death is often unascertainable, as it is only in those cases where bony injury of a lethal nature is present that any opinion can be given. Firearm wounds and blunt impact injuries to the head fall into this category. After the last War many Servicemen who were alleged to have been murdered after having been taken prisoner were examined, and as the majority had been murdered by shooting through the back of the head, ample evidence of the crime was usually present.

The identification of the remains may be dealt with under six headings :-

(1) Sex. A skeleton, except in the rare cases of intersexuality, exhibits well defined secondary sexual characteristics. Most doctors are fully familiar with the difference between the male and female pelvis ; the anatomist, however, is able to use almost any bone of the body in making his assessment. In the majority of cases there is sufficient material for the pathologist alone to be able confidently to sex the skeleton without the assistance of an anatomist.

According to Krogman the degree of accuracy attained in sexing a skeleton is 100% if all the bones are present, but a very high degree of accuracy is also obtained from examination of the pelvis and skull. Even a small bone such as the first cervical vertebra may be quite sufficient for sexing if the deceased exhibited definite male or female characteristics.

TABLE 1 SEXING OF HUMAN SKELETAL REMAINS

Accuracy (Krogman)

Whole Skeleton 100% Pelvis 95 % Skull 92 % Pelvis and Skull 98% Long Bones alone 80-85 % Long Bones and Skull 95 % Long Bones and Pelvis 98 %

(2) Height. The height of the deceased can be calculated by reconstructing the skeleton and then measuring it, having made due allowances for the cartilages which lie between the bones of the vertebral column. As a complete skeleton is frequently not available for measurement, the height may be calculated by measuring the long bones and applying one of the recognised formulae. There are several such formulae in existence, and the recent one compiled by Trotter and Gleser would appear to be the most accurate. The more bones available for measurement, the greater the accuracy of the assess- ment, an average being taken of the heights calculated from the various long bones.

When interpreting the results one should always bear in mind that the deceased may never have been measured during life, and even if recorded proper allowance may not have been made for shoes or boots.

(3) Age. Assessing the age of the deceased from skeletal remains is frequently the most difficult problem. There are very many observations which can be made to assist in this assessment-the eruption and degree of wear of the teeth, the final ossification of the ends of the various bones with the disappearance of

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cartilage, the closure of the sutures between the bones of the skull, and the various Continental techniques where the interior of the bone is studied both macro- scopically and microscopically.

Unfortunately the problem is not resolved as easily as one might anticipate from the literature. In many cases there are gross variations from the considered normal, and it is most unwise for anyone except an anatomist who has specialised in this sort of work to be dogmatic a t any time, and especially when only a portion of the skeleton is available for examination.

Methods for the estimation of age from study of the teeth have been developed in recent years, and when this work is undertaken by an expert i t may offer a fair degree of accuracy.

(4) Bony deformities and disease. The presence of bony deformities, or diseased bones and joints, may clearly assist in establishing identification. Old fractures perhaps provide the most positive assistance as medical records will almost certainly be available. It is not uncommon in cases of advanced disease of the bones or joints with marked deformity to find that i t was un- noticed in life by the relatives and friends, and frequently uncomplained of by the deceased.

(5) Dental Data. Perhaps the most important method by which a skeleton can be identified is from the dental data, provided that dental records are available. Even dentures are normally identified by the dental surgeon who made them. Every effort should be made to recover all the teeth belonging to the deceased. If the skull has rolled some distance from the remainder of the skeleton this search may be long and laborious, involving the sifting of a con- siderable quantity of earth, but if positive identification is essential this is a necessary procedure.

In a large number of cases identification of the remains is only made finally positive when the dental surgeon who treated the deceased has been traced. In the case of R. v. Dobkin positive identification was only established when the victim's dental surgeon came forward having recognised his dental work from the description circulated. Excellent dental records for circulation may be made by photographing the teeth after the jaws have been cleaned.

(6) Race. If the race of the deceased is questioned the remains must be referred to a skilled anthropologist.