A young single mother is found murdered in her new Iowa duplex, and a bloody footprint pressed into a hamburger bun becomes the unlikely clue investigators follow into the case.
When a police constable is gunned down on a routine call in Bradford, England, the UK's first city-wide number plate recognition network sets out to track the killers across the country.
A beloved bookstore owner is murdered in Utah, and a single drop of blood holds its secret for ten years as DNA science races to catch up.
A mother of five vanishes on Prince Edward Island, and twenty-seven white hairs in a bloody jacket point investigators toward a groundbreaking and unexpected source of evidence.