Fingerprinting has long-been seen as the Gold Standard of forensic science. This century-old discipline has played a key role in evidence-gathering for law enforcement agencies around the world.
But Claudia Hammond investigates the science behind fingerprinting and hears claims that this branch of forensic science is fallible, subjective and lacking in scientific rigour.
She considers a growing body of research from cognitive psychology and neuroscience which demonstrates the very real potential for mistakes, despite the fact that for years, fingerprint experts have claimed that if their methods are used correctly, their error rate is zero.
Claudia hears from Brandon Mayfield, a lawyer from Oregon in the USA, who faced a possible death penalty when FBI experts asserted that they were one hundred per cent sure that his fingerprints matched a print found at the scene of the 2004 Madrid train bombings. The FBI was forced to release Mr Mayfield and issue a public apology.