In the composite scenario that is created when the investigation process is activated, there are various degrees of collaboration that can develop with the aid of psychology and criminology; when a crime is committed, both these disciplines can ensure, to those who investigate, the necessary knowledge to be able to select preliminary theories. This book helps the reader to draw up a psychological analysis of the crime scene, with the correct techniques to interrogate suspects, develop the correct approach to victims and witnesses (especially if minors). Criminology and psychology can be profitably used also in specific training activities aimed at increasing the technical-professional skills of the investigators and the book emphasises this advantageous synergy to reach the main objective of creating a new operational mentality always starting from a correct knowledge of the procedural and criminal systems of reference. The aim is to support those who are working on the field, offering them instruments that allow the emergence of the motivations and interior aspects that have led the criminal to act in this way, and thus have a better understanding of his psyche. This book is very useful in examining in depth the behaviour of all the protagonists at the crime scene and in making the investigation more sensitive to the human aspect; for these reasons it is necessary to “INVESTIGATE MASTER CRIME” with the use of psychology and investigative criminology. Captain Carillo’s book reflects this new way of investigating, which has become necessary in order to synergically overcome the apparent contrast between scientific testing and witness testimony. The empirical confirmation of the assessment analysis of the object (exhibit) with the study of the conduct of the protagonists in the case under investigation.