On August 29, 2019, former inspector, Keith Farquharson who repeatedly cheated on wife Alice Farquharson killed her after she asked if he still loved her. Despite the 60-year-old's adultery and his demotion for sending a pornographic poem to a female officer, Alice stood by him. Cops Who Kill lifts the lid on eight cases of murder and betrayal by police officers in Britain and around the world. In each episode, TV personality and actor Will Mellor is joined by experts, including ex-Detective Superintendent Julie McKay, psychologist Serena Simmons, and ex-Murder Detective Howard Groves, to try to unravel how and why a police officer switches from law enforcer to lawbreaker, how they were finally brought to justice, and the horrendous consequences for all concerned.