The success of M. Bertillon’s system in France speedily led to its adoption in other countries. Early in 1892 it was introduced into India, and within six years upwards of a quarter of a million of classified cards had been collected.
The chief difficulty was found to be in the classification of the measurements for reference, and a committee was accordingly appointed by the Indian Government to report upon the system. Their report stated that the finger-print method was preferable to the anthropometric system in simplicity, rapidity and certainty.
Since that time (June, 1897) the finger-print method has been in use in India for the identification of criminals.
The system of identification by bodily measurements, which has now come to be known as bertillonage, was first introduced as a method of police registration in Paris in 1882. During the first year of its employment it detected forty-nine criminals giving false names, while in the following year the number rose to 241.
In 1889 M. Bertillon stated that there had not been a single case of mistaken identity since the system had been introduced, and that in the previous year 31,849 prisoners had been measured in Paris, 615 of whom were in this way recognised as former convicts, while fourteen were subsequently recognised in prison. Of the latter, ten had never previously been examined, so that the failures were only four in 32,000, or one in 8,000.
The system, as described by M. Bertillon himself in a pamphlet on The Identification of the Criminal Classes, consists in taking the measurements of the body structure of each individual. Although such measurements might be indefinitely extended, the number is usually restricted to twelve, including the height, length and width of the head, length of the middle finger, of the foot, etc.
These measurements are rapidly taken with standard instruments by a special staff, and are recorded upon a card upon which are pasted full face and profile photographs of the prisoner.
The data obtained enable the photographs to be classified into different groups of short, medium, and tall men, and these, again, may be subdivided into groups of short, medium, and long heads, while further subdivisions are afforded by the width of the head, width of the arms outstretched at an angle of the body and so on. The colour of the eyes affords the means for a further subdivision, while special birthmarks or peculiarities differentiate the individuals still further.
In this way alone, M. Bertillon claims that 100,000 persons can be classified into groups of ten each, the portraits in which would offer no difficulty in examination.
M. Bertillon undoubtedly puts the position too favourably here, in assuming division into equal groups; for out of his hypothetical 100,000 individuals, seventy-five per cent. might conceivably be tall men, and seventy-five per cent. of these, again have long heads, so that the final groups would in some cases have no representatives, while in the other groups there might be 1,000 individuals.