He is 29 years old and commits his horrendous crime alone. He is an underachiever, unskilled, doesn't have a regular job and he is now a mass murderer. What made Martin Bryant go on a brutal killing spree at Port Arthur taking the lives of 35 people? Working with a leading Australian forensic psychologist, investigative journalist Rochelle Jackson takes us deep into the minds of eight of the country's most notorious criminals: serial killer, Ivan Milat; female sex offender, Karen Ellis; serial arsonist, Peter Burgess; armed robber and escapee, Brenden Abbott; child killer, Kathleen Folbigg; murderer, Matthew Wales; and gangland warlord, Carl Williams. She probes their motivations, delves deep into their pasts and unlocks the dark side of their humanity.