This two-part true crime special features unprecedented access behind the scenes of the largest ever unsolved murder case in the history of Cambridgeshire Police.
The killing of Rikki Neave, a six-year-old child, shocked the nation 27 years ago. Only now can the full truth be revealed of how a killer remained unpunished and on the loose for nearly three decades.
It's a cold, dark November afternoon in 1994 when Rikki Neave fails to return home. His mother sounds the alarm, but there's no trace of the six-year-old that night. Rikki's body is found the next day, laid out in woodland close to his home; he is naked and has been posed in a star shape.
A murder investigation is immediately launched. In a climate where Jamie Bulger's murder happened only a year earlier, the press are quickly in full cry, and there's immense pressure on the police to find answers fast.
The police know they have an unusually tricky case on their hands. As Assistant Chief Constable Paul Fulwood admits: 'Most murders are solved in the first 24 hours, but this was a real whodunnit.' Detectives first turn their attention to Rikki's mother, Ruth.
The rumour on the estate was that she was a bad mother. The clear evidence of neglect of her children means she becomes the police's prime suspect. Before long, they discover that Ruth seemed to have an interest in murder and black magic. Seven weeks later, Ruth is arrested and charged with her son's murder.
Ruth Neave consistently maintains her innocence of Rikki's death and the original investigation team struggle to prove her guilty of murder. As a new team is brought in to find the truth, cameras follow every twist and turn of the fresh investigation of this 'cold case', which painstakingly exposes flaws in the original police work and eventually finds a compelling new lead.
This is the real-life drama of how police and the justice system failed a murder victim, but where eventually, due to the determination of a small team of dedicated detectives, fresh hope of justice was found.
Both parts of this special will be available to stream or download for free on All 4 following the transmission of this episode on Monday 4th July.