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

In 2018, two paralegals are shot dead while at work in Scottsdale, Ariz; four more victims are linked to the killing.

A beloved local teacher is brutally attacked in her Pennsylvania home; after 27 years, dedicated investigators trace her killer.

A lorry driver is found dead behind the wheel in Camberley, England; police use a revolutionary technique of familial DNA analysis.

A young woman's body is discovered close to her home in Bath, England; police eventually track down the perpetrator of the heinous attack.