What makes a serial killer? How do you spot one? Is there any way of truly knowing? David Canter asked the same questions whilst developing the new science of criminal profiling, a revolutionary approach to violent crime investigations. In this highly acclaimed account, Canter reveals his methods of precisely identifying and locating murderers and rapists: the unconscious behaviours and tell-tale patterns that they always leave behind. These pioneering techniques of building profiles transformed policing, still in use across the world to hunt and capture dangerous psychopaths. Taking us into the heart of some of the most notorious criminal investigations in British history, Canter's writing is a gripping read for fans of true crime and human psychology. 'Fascinating. A persuasive and thorough contribution to a nascent science' Mail on Sunday