Interview with Dr Peter Vronsky, author of "Sons of Cain: A History of Serial Killers from the Stone Age to the Present", the book which more than any other has been foundational to informing the development of this podcast series. Dr Vronsky talks about how he developed his theory regarding the historical and neurobiological roots of serial murder, and his chance encounters with two infamous serial killers, Richard Cottingham and Andrew Chikatilo