In November 1990 a body of a woman was discovered - near an abandoned farm house in Missouri. The victim had been restrained with six types of rope. Police had no idea who she was, let alone who had killed her. With no clues to go on, and no leads, the police dubbed her ‘Grace’ after one officer said ‘only by the grace of god will she be identified’. For three decades there wasn’t a single lead in the case. However earlier this year, the young woman was identified using a revolutionary technique. It combines advanced DNA genome processing with genealogy websites which people use to trace ancestors and build their family trees. The BBC’s North American technology reporter, James Clayton, discovers Grace’s true identity and meets the victim’s siblings who are grateful to finally get some sense of closure after years of uncertainty. The new method has already solved hundreds of cold cases across America. Yet some worry that uploading DNA onto police databases violates privacy and could be open to abuse.