adrian tawse

Weymouth

IT Consultant

It is not true that we do not know how unique fingerprints are. The Home office sent me a vey interresting document - probably by mistake - detailing American experiances with work permits for Mexicans and the automatic matching of fingerprints. There are two modes of faiure, false accept, and false reject. To a certainn extent the system can be tuned for one at the expence of the other, but braudly the failure rate is 0.3%. At first sight this seems quite good but if the question is "who is this person given a fingerprint" this would match to about 15000 in the population of the UK, and that is with professionally taken prints. The oft repeated scene in cops and robbers programs where, after a few taps on a keyboard, someone declares "we ahve a match" and they rush off to arrest the culprit is complete fiction.