Sir William Herschel, Chief Magistrate of the Hooghly district in Jungipoor India, was the first to use fingerprints and palmprints on contracts with native Indian " ... to frighten [him] out of all thought of repudiating his singature."
Herschel made a habit of requiring palm prints--and later, simply the prints of the right Index and Middle fingers--on every contract made with the locals. Personal contact with the document, they believed, made the contract more binding than if they simply signed it. Thus, the first wide-scale, modern-day use of fingerprints was predicated, not upon scientific evidence, but upon superstitious beliefs.
Checkout more on the History of Fingerprints: Link (via Scribal Terror)