The handbook “Investigazioni di Polizia Giudiziaria” (Criminal Police Investigations) was first published fifteen years ago as a professional teaching aid for those people whose work involved investigations. It has evolved over the years and legislative innovations have been added as they have come into effect, as have new professional experiences and updated investigation methods. Now in its seventh edition, the book sums up state-of-the-art investigation techniques, masterfully discussed by the authors within a scientific context aimed at giving an in-depth view of operations by investigators on the scene of a crime. The concrete and psychological elements that an investigator must always be aware of, procedures that must be followed, technical operations that must be implemented. An explanation of existing criminal organisations and anti-crime legislation are presented as individual sections in order to offer a clearer view of the delicate and complex subject that is criminal investigation. Clear, complete (in as far as this is possible for a subject that is constantly evolving) and always useful as the authors offer simple explanations placed within the correct training context and try to unravel the subject, helped almost always by professionals within the field. It is a useful guide to a multi-faceted profession where contents are not always encoded.