Overview: Four of Britain’s best-known crime writers turn detective in a brand-new series Once Upon a True Crime. Featuring Peter James, Denise Mina, Mark Billingham and Douglas Skelton, the show investigates the real-life murders that inspired some of the acclaimed authors’ most famous novels. In each episode, the writers retrace the steps of the killers and victims, taking viewers through every twist and turn in the story. With unprecedented access to experts, witnesses and journalists that covered each case, the murders are pieced together and new, untested theories surface in attempt to resolve mysteries that remain.