One of the authors of this book, John Douglas, was a special agent of the FBI in the United States of America for twenty-five years, and until recently headed the auxiliary investigative department in this Bureau. He has over a thousand investigated cases involving the commission of serious crimes, including brutal serial murders, murders related to the abduction and sexual exploitation of children in the United States. John Douglas talks about the work of his department and, in particular, about the fruitful search for criminals based on the method they developed - analyzing the personality profile of the killer - using photographs from the crime scene. John Douglas and his colleagues not only accurately identified the type of criminal, but also described his behavior after the crime. The book equips the reader with the experience for which many of the heroes of this sad story paid with their lives.