
Detectives and forensic experts recount the most extraordinary cold cases that were solved using the revolutionary technique of familial DNA testing.
Carla Walker is raped and killed on Valentine's Day, 1974, leading to a cold case that takes 46 years to crack.
A seven-year-old girl is kidnapped and raped, but it takes almost 20 years for her assailant to be caught.
In 1987, Terry Wood finds his wife Roxanne dead; genetic genealogy pinpoints her killer 35 years later.
A lorry driver is found dead behind the wheel in Camberley, England; police use a revolutionary technique of familial DNA analysis.