Scotland Yard The methods and organisation of the Metropolitan Police

Excerpt: ... finger-print as other men can read a letter, and has even, for the purposes of study, taken prints of the fingers of monkeys at the Zoo. Many times has he given evidence as an expert in cases where finger-prints have formed part of the evidence. His cold, scientific analysis has always convinced the most sceptical, and always a conviction has followed. He wrote the chapter dealing with the photographing and enlarging of finger-prints in Sir Edward Henry's standard work on the subject, and is something of a magician in the way he can detect a mark when none is obvious to the naked eye. I have seen a man press his fingers on a clean sheet of paper, apparently without leaving the faintest trace. But Mr. Collins is not baffled so. A pinch of black powder—graphite is commonly used—scattered over the paper, and behold the prints standing out in high relief. A grey powder will act in the same way on a dark surface, and a candle which has been pressed by the fingers may have the print rendered clear by a judicious use of ordinary printer's ink. A corps of expert photographers, equipped with the latest appliances, is attached to the department, and their services are in constant requisition by the C.I.D. for many purposes other than those of finger-prints. Pg 72 One room is entirely devoted to a powerful lantern apparatus by which every photograph may be thrown up to a hundred times its normal size for the purpose of minute study. This has often proved useful in detecting forgeries as well as aiding the work of the Finger-print Department. I have said that the primary purpose of the department is not the detection of crime. Nevertheless, it has played no small part in the solution of mysteries where other clues have failed. There was the case of the Stratton brothers, for instance, where the print on a cash-box led to arrest, although other evidence aided the conviction. Perhaps the most interesting case is that which first focussed the public...