Rose West is the UK's most prolific serial killer. She and her husband, Fred, murdered twelve women and girls, subjecting them to horrific sexual violence before they died, including their own daughter, Heather, aged sixteen, and stepdaughter, Charmaine, eight.

Rose West was, on the face of it, a mother living with her family in a semi in Gloucester. But behind closed doors, she was a monstrous killer who, with husband Fred, killed at least a dozen women and girls, including her own daughter Heather, sixteen, and stepdaughter, Charmaine, eight.

Rose was sadistic as both a mother and killer, and all her victims as well as her own children were subjected to horrific sexual violence and torture. Rose did paid sex work in the family home with husband Fred peeping through the holes he had made in the wall and listening on an intercom. They modified the house to take in lodgers and then preyed on them, as well as other young women hitching a lift or waiting for a bus.

In 1972, aged seventeen, Caroline Owens, who had been hired as a nanny, was drugged, attacked and raped, but managed to escape. But she could not bring herself to testify, so the Wests remained free.

Two decades would pass before Rose's dark secrets were discovered when nine of the victims' bodies were dug up in the garden and beneath the cellar at the West's home at 25 Cromwell Street. And now, three decades after this grim discovery, the workings of Rose West's twisted mind remain as mysterious as who played what role in this husband-and-wife folie à deux.