In this book, I would like to present an approach to psychological expertise in the judicial environment, when the judge calls on a psychologist to enlighten him on the personality of the defendant.The psychologist's work must be well structured, rather than going off in all directions and presenting himself as a charlatan who doesn't know where to start in order to enlighten the justice system, which calls on the services of a psychologist. Each person has a cycle of self-realization, unlike Maslow, whose pyramid I demonstrated at length in my work. Each person has a cycle of self-realization, as in the case of a defendant who has committed a legally reprehensible act.The fundamental question for justice is: what was the mental structure at the time of committing the act? And how does this structure relate to the act? To provide effective answers, we need a working methodology, which is what I propose in this book.