Although the system of identification by fingerprints has been in use in Europe for a number of years, it is not a European invention. As a matter of fact, it is one of those cherished western institutions that the Chinese have calmly claimed for their own, and those who doubt this may be convinced by actual history showing it to have been employed in the police courts of British India for a generation or so back. Just who was responsible for its adoption there is not certain, but Sir John Herschel, at one time connected with the India civil service, is usually mentioned in this regard. The British police experienced a great deal of trouble in keeping track of even the most notorious native criminals and it was a great deal more difficult to arrest a first offender, for the reason that all the natives looked so much alike and were such apt liars.
Ordinary methods, even the Bertillon system, were fruitless and finally the finger-print scheme was tried. It worked like a charm. Where more arrests had been the exception, they now became the rule and the power of the law began to merit respect. In case after case the police were enabled to track the crime solely by the chance print of a man's finger or thumb on an odd piece of paper, on the dusty lintel of a doorway or a dirty window pane. Some of the stories told of their accomplishments in this line rival the most thrilling detective stories.
In one case, that of the murder of a manager of a tea garden on the Bhupal frontier, half a dozen or more persons were at first suspected, among them the real murderer, who was, however, later regarded as innocent because he was supposed to have been away from the district at the time the crime was committed. Investigations and questionings did no good, and at last the local inspector decided to take the thumb-prints of all concerned and refer them to the central office of the province. After the records had been searched a messenger came with orders to arrest the discharged servant of the manager who had been first suspected and then exonerated, for his finger-prints tallied exactly with those of a bad character just discharged from prison. He was later convicted of burglary by a court of appeal, to which the case was carried, the court refusing to condemn a man for murder on such slight basis when the actual crime had not been observed.
At the present time in India the papers taken in the civil-service examinations must be certified to by the thumb-print of the competitor and wills must likewise be sealed in the same way, and all checks and drafts must be certified by a thumb-print in addition to a signature.
In India, also deeds of transfer, and records of sale of land in connection with illiterate natives are executed by the impression of a thumb-mark instead of an "X, his mark"; and recently this very superior system of signature has been applied to all kinds of transactions with the natives, such as post-office savings banks, pension certificates, mortgages, etc.
The success the plan met with in India led to its trial and speedy adoption by the French and English police. In Paris it is used as an adjunct to the measurement system of M. Bertillon, but at Scotland Yard the Bertillon system has been entirely done away with and full reliance is had on the prints. M. Bertillon claims to have 500,000 prints in his collection, although this is said by the authorities to be an exaggeration, and Inspector McNaughton of the convict supervision office has at least 100,000 criminals' hands catalogued in his office.
Finger marks do not change in any way through life, and any injury only temporarily affects the pattern. The pattern becomes larger as the youth develops into a man, but the arrangement of the lines remains absolutely the same.
Thumb-marks may be generally classified as loops, arches and ovals, or whorls; the ovals irresistibly remind one of whirlpools as well as the volutions of shells, while the majority of loops or arches resemble in their convolutions the rapid movement of rushing water.
Thumb-print identifications have been extended to commercial uses by the postal savings bank on the Philippines at Manila. This bank has recently issued a series of stamp deposit cards, on which are spaces for stamps of different values to be affixed. When the depositor has stamps to the value of 1 peso (50 cents) on the card it is exchanged at the bank for a deposit book, showing the amount to his credit. Opposite the lines for the owner's signature and address is a square ruled off for the reception of his thumb-print, so that even if illiterate, depositors may readily be identified.
If any one wishes to get a thumb-print impression without the suspect's knowledge, simply hand him a piece of paper, asking him to identify it or examine it for one reason or another, afterwards sprinkling some special black powder over it which brings out the impressions as clear as life. Another sort of white powder is used for bringing out impressions on glassware.