Michael O'Brien spent 11 years in prison for a murder he didn't commit. His case, the Cardiff Newsagent Three, was one of several with a "common thread" - a vulnerable person being cajoled into a confession upon which South Wales Police built a flawed case. In this special episode I interview him at length about the case and about how he coped in prison and upon his release. He has triumphed over adversity and become a prominent campaigner against miscarriages of justice.

In today's episode I have an exclusive interview with John Burke-Monerville who has the unwanted distinction of being the father of three sons who were all murdered - in 1994, 2013 and 2019 - in London. But as if John's story was not tragic and shocking enough, it has emerged in recent years that he and his family were spied on for years by undercover officers.

In today's episode I visit the Metropolitan Police Museum, where they have artefacts from 150 years of crime. I interview Dr Clare Smith, the museum's curator, about the collection and focus on "The Brides in the Bath" case in 1915, which involved a bigamous serial killer who managed to turn bathtubs into murder weapons. The interview took place in the same room as an exhibition which includes one of the bathtubs (pictured).