Investigating the murder case of Samo Paul and Tracey Turner from the 1990s. In 1997 former Chief constable Mick Creedon and his team in Leicester announced that the cold case murders are the work of one man- a serial sexual predator who is still out there. Creedon uses the DNA in an attempt to catch the killer before he strikes again.

Stefan Kiszko was convicted of murder when 11-year-old Lesley Molseed was found dead on the Yorkshire Moors. Sixteen years later he was declared innocent, so who did kill Lesley?

A mishandled prosecution ended in a murderer going free until new evidence came about.

The gripping series returns with the case of a multi-generation murder in Wales. It took years to bring the killer to justice - had they been hiding within the police's own ranks?

On the tenth anniversary of Vikki Thompson's brutal murder in the Thames Valley, a new lead emerges that results in the case being re-opened.

A woman disappears and an investigation identifies the likely culprit to be her boyfriend.

Soon after the corpses of two teens were found, a decades-spanning investigation began.

Ten years after local Cardiff girl Geraldine's body was found a few days before Christmas, Detective Superintendent Paul Kemp and his team set out to catch the culprit with new groundbreaking forensic science. However, when they get a DNA match to a suspect they must act fast as he is about to be released from Dartmoor Prison.

In 1979, 22-year-old Teresa de Simone is found murdered in the back of her car. Sean Hodgson is found guilty and sentenced to life but hopes that new DNA technology will clear his name.

After 19-year-old Cassandra McDermott is found dead in her home, her family endure a cruel waiting game as their only hope for justice is if the murderer tries to kill again.

Thirty years after her murder, could changed loyalties help find Sally McGrath's killer?

How it took 14 years to bring Shamsuddin Mahmood's killer to justice.