This examination of forensic science ranges from the origins of blood and fingerprint identification to today's reliance on "expert witnesses" and DNA tests, and the misuse and misunderstanding of forensic evidence. A few key cases from around the world are interwoven with historical research to show how forensic science requires interpretation and is not as definitive as judges and juries would like. Accompanying a BBC television series, the book presents a story of horror and human tragedy, luck and skill, arrogance and black humour, and failure and success.