Throughout his time as a murder squad detective, Trevor Marriott has seen first-hand the wanton slayings and butcheries that have been committed by both men and women who have warped, depraved and sadistic minds.

Since the dawn of time, man and woman have been killing each other, and during his time as a murder squad detective, Marriott has witnessed first-hand the work of depraved minds. Here he examines some of the world's most notorious serial killers, including William MacDonald, Peter Kurten and Steve Wright.