As the number of serial killers worldwide has risen steadily - from the emergence of Jack the Ripper in 1888 to Harold Shipman and Ivan Milat, the backpacker killer of the Australian outback - the need to understand mass murder is becoming more urgent. Using privileged access to the world's first National Centre for the Analysis of Violent Crime, Colin Wilson and Donald Seaman bring you this incisive study of the psychology of serial killers and the motives behind their crimes. From childhood traumas to issues of frustration, fear and fantasy, discover what turns an ordinary human being into a compulsive killer.