
Detectives and forensic experts recount the most extraordinary cold cases that were solved using the revolutionary technique of familial DNA testing.

In 1973, two young girls are found murdered in the Welsh village of Llandarcy; the killer's identity remains a mystery until 2002.

With the help of familial DNA, detectives are able to track down and capture a serial rapist.

The exhaustive investigation into the murder of Tangie Sims; how genetic genealogy gave investigators the break they'd been waiting for.

A 69-year-old woman is found brutally murdered in 2011; after the case goes cold, new DNA technology eventually leads detectives to the truth.