In July 1957 two young police officers on a routine traffic stop in El Segundo, Calif., a Los Angeles suburb, were gunned down and murdered by a man who the police did not know had just committed robbery and rape at a nearby lover's lane. The gunman fled, triggering one of the largest manhunts in California's history. It would take detectives and modern science close to half a century to bring this case to a startling conclusion.

Fourteen-year-old Michael Crowe of Escondido, Calif. confessed to murdering his 12-year-old sister, Stephanie, in her bedroom in January 1998. But was he telling the truth or was it another man, a drifter named Richard Tuite, who stabbed Stephanie while she slept? 48 HOURS