I Thought Mum Was Safe

When a man confesses that a woman is lying dead in his house, police must establish whether she died as a result of an accident or if she was murdered. There is also a look into the Crimewatch archives. Detectives and forensic experts describe how Pembrokeshire killer John Cooper was finally found guilty of murder, decades after he committed his crimes. Advances in forensic technology finally helped police crack these two infamous double murder cases.