How far should fingerprints be trusted?

No one disputes that fingerprinting is a valuable and generally reliable police tool, but despite more than a century of use, fingerprinting has never been scientifically validated. This is significant because of the criteria governing the admission of scientific evidence in the US courts.

It's quite an interesting read at from New Scientist News. Lest you doubt that fingerprints can wrongly convict someone of a crime check this out:

The most high-profile mistake involved Brandon Mayfield, a Portland lawyer, who was incorrectly identified from crime scene prints taken at one of the Madrid terrorist bombings on 11 March 2004. Despite three FBI examiners plus an external expert agreeing on the identification, Spanish authorities eventually matched the prints to an Algerian.

Luckily, they caught that one in time. Terrorism carries a death penalty in many countries.