It was an ordinary semi-detached with grubby walls and net curtains. A young man answered the door to police officers with a search warrant, intent on digging up the back garden. The house was 25 Cromwell Street; the man the eldest son of Fred and Rose West. The world's most shocking murderers were somebody's neighbour, someone else's dad. Why do they do it? What turns a person into a killer? And why are we fascinated by them? From Arsenic Annie to the Zodiac Killer, this chilling compendium features a deadly real-life cast of the most barbaric killers of all time.