Somali seaman Mahmood Mattan was hanged for a crime he didn't commit. On March 6th, 1952, Lily Volpert was murdered in the shop she ran in Cardiff's Tiger Bay. What followed was a flawed police investigation and prejudiced trial that ultimately led to Mahmood being hanged for a crime he was not responsible for. After 46 years, his innocence was finally proved in a court of law. But the impact of Lily's murder and Mahmood's execution are still being felt by two families today. For the first time, we hear from the family of murder victim Lily. Ruth was just yards away when her aunty was murdered, and she still doesn't know who killed her. And the surviving family members of Mahmood's family open up about the trauma they felt - and continue to feel to this day - 70 years after Mahmood was hanged.