Now more than ever, forensic science is opening up the possibility of catching criminals for crimes that have remained unsolved for years. In this episode, a case that had lain dormant for 30 years is revitalised when a new forensic investigator examines the evidence. Glasgow woman Mary McLaughlin was found strangled to death at her West End flat in 1984. Without witnesses or other crucial leads, the case remained cold until 2014, when forensic biologist and DNA specialist Joanne Cochrane was asked to re-examine Mary's clothing. Joanne's analysis of a dressing gown cord opened up the case and led to the conviction of a notorious sex offender. Mary's daughter Gina McGavin recalls the terrible impact her mother's murder had on the family and the relief that the killer was finally caught. In our second case, police made a gruesome discovery in east London in the summer of 2022 - a young female student's body had been placed in a suitcase and dumped on a quiet roadside. Hina Bashir was just 21 years old, and police were quick to suspect Hina's friend Muhammad Arslan. But when Arslan denied being in the area where Hina's body was found, detectives enlisted the help of soil analyst Professor Lorna Dawson. Lorna's expertise became crucial in placing Arslan at the crime scene and led to a life sentence for the callous killer. Hina's father recalls the pain of the discovery of his daughter's remains and the search for justice.