To anyone looking in from the outside, Dan Seggie seemed like a devoted son living with his elderly father. But questions are quick to rise when Dan mysteriously disappears and his Dad stops turning up to work. Was Dan really the loving son everyone thought him to be, or was he a savage killer? Fronted Philip Glenister, and supported by compelling testimonies from serious crime detectives, defence lawyers and expert criminologists and psychologists, What The Killer Did Next provides a step change in true-crime storytelling by focusing on the behaviour of killers in the immediate aftermath of a murder to unpick their mind-set and understand their motive.