BY “FINGER-PRINTS.”

Horowhenua Chronicle, 4 March 1937, Page 3

BY “FINGER-PRINTS.”

The increasing number of crimes carried out with.the aid of motor-cars has led to the invention of a new department of criminology by Deputy Sheriff Chapman, of the Los Angeles Police. With the co-operation of other police departments in all parts of- the world he hopes to “finger-print” motor cars so that identification becomes as simple as it is with human fingerprints.

The “finger-prints’' of a car are the marks left by its tyres. So far the inventor of the now science has tabulated 447 different types of tyre, according to size, tread, and so forth. But these are only the main headings. Two cars of the same make using the same type of tyre, will leave different marks and can be distinguished by the expert. By obtaining the assistance of the type manufacturers, Mr. Chapman has been able to file 13,000 blue-prints of tyre treads, and a short examination of the marks left by a car in the dust enables him to state its make in a short time. When some crime has been committed, if the road is hard and dustless, aluminium powder is scattered. This throws up the tyre prints. Measurements are made and the prints photographed for record purposes. In the case of prints made in soft material, plaster of Paris easts can be taken. By the new method the police are able to state the make of car with certainty in a few minutes. Any officer holding up a car of the suspected make telephones headquarters for further instructions, and receives information which enables him to cheek up on the car’s tyres by' means of his manual of standards.

The number and position of the passengers in the car are revealed by the breadth of the marks when compared with standard marks. Obviously the more heavily loaded the car the wider the marks, and it is thus possibie to state whether the driver was alone, had a passenger in the frontseat, or two in the back. In the case of lorries, it enables the expert to determine the approximate weight of the load.