In September 2021, in Killamarsh, Derbyshire, 2 children, their friend and their mother were brutally murdered in the place they should have been safest – their own home. A subsequent investigation uncovered catastrophic failings by the Probation Service – failings that had deadly consequences. This is what happens when a drug-abusing, violent predator enters the world of a happy family. This is the case of mass murderer, Damien Bendall