Two elderly shopkeepers bludgeoned to death, the only evidence - a smudged thumbprint inside a cashbox. A Quaker poisons his mistress in Slough and, confident he will evade justice, arrives at Paddington station unaware modern technology had alerted police who lay in wait. Great Britain has led the world in crime-detection methods and the forensic sciences; this volume examines real criminal cases that have tested the legality and admissibility of...