The story of killer Dale Cregan, who hit the headlines in 2012 when he murdered police officers Nicola Hughes and Fiona Bone during a routine callout to a house in Hattersley, Greater Manchester. Lying in wait for the officers, Cregan used grenades and other high-powered weapons , giving them no time to escape. But his crimewave had started some months earlier, with the killing of a father and son, David and Mark Short. Featuring contributions from the fathers of Nicolas and Fiona, as well as the Chief Constable of Greater Manchester Police Peter Fahy, and journalist Adam McClean.