Science and the Criminal

by C. Ainsworth Mitchell

In recording the colour of the eyes a special table is used, the scale of which is based upon the intensity of the pigment of the iris. A number corresponding to one of the following groups is then assigned:—(1) Iris, azure blue, with areola pale but free from yellow pigment; (2) Iris blue or slate, with light yellow areola; (3) Same shade, with larger areola approaching orange; (4) Iris, greenish reflection; hazel areola; (5) Same shade with dark hazel areola; (6) Hazel distributed over surface of iris; (7) Eye entirely hazel.

When first the system was introduced into Paris it was a common practice for the old offenders to change their names and try to escape identification, but, according to M. Bertillon, after a few years this was only done by those who had been away from Paris for a long period, or had some very special reason for attempting to slip through the examination unrecognised.

A similar method is employed in the United States Army for recognising deserters. Each man on joining is measured, and an outline figure card showing the measurements of the front and back surfaces, which are divided into areas by means of dotted lines, is filed in the Medical Department of the War Office. When a man deserts or is dismissed his card is placed in a separate file, and the new cards of recruits are compared with those in this particular file.

A special register, ruled into columns corresponding to the areas on the cards, and giving the measurements and any peculiarities such as scars, tattoo marks, etc., is used to facilitate the search, and when, on reference to this, there appears to be a probability of a recruit being identical with a deserter, the original card is used for the comparison.

During the first five months after the system was instituted (1891) sixty-two men were suspected of concealing their identity, and in sixty-one of these cases the suspicion was justified and the identity acknowledged.

A drawback of the Bertillon system of identification is that much depends upon the accuracy of the person who takes the measurements, and that, therefore, a permissible error must be admitted. In the United States Army an error of one inch in either direction is allowed, for the recorded height. In addition to this, some degree of natural variation will take place in the course of years, and due allowance must also be made for this influence upon the measurements.

Striking as has been the success of M. Bertillon’s system of anthropometrical measurements as a means of identification, it has been altogether surpassed in certainty by the methods of recording the impressions of the fingers. From time to time in the past use has been made of a finger or thumb impression as a seal or to give a personal mark of authenticity to a document. One of the earliest examples extant of the use of the manual seal is to be seen on one of the Assyrian clay tablets in the British Museum.

This is imprinted in cuneiform characters, and contains a notice of the sale of a field, which concludes with the imprint of a finger nail, and the statement that this had been made by the seller of the field as his nail mark.

Similar imprints of nails are to be seen upon Chinese coins, as has been pointed out by Sir Francis Galton, and a tradition has it that they were first put there as a compliment to an early Chinese Empress who had accidentally pressed her finger nail into the wax model of a coin that had been submitted for her approval. The ancient Egyptians caused criminals to seal their confessions with finger nails.

There are also numerous instances in which impressions of finger-tips are found upon documents, but these do not seem to have been put there with any idea of identification, but rather to have been of the nature of a ceremonial observance comparable with the legal survival of putting a finger upon the seal of a document, and delivering it as “my act and deed.”