THE PRIMARY CONCERN OF THE BOOK IS PRACTICAL CRIMINAL INVESTIGATION, WHICH CAN BE ENHANCED BY AN UNDERSTANDING OF THE MANY DIVERSE BEHAVIORS UNDER STRONG PSYCHOSEXUAL INFLUENCES. INVESTIGATORS ARE TAUGHT TO RECOGNIZE AND APPLY INFORMATION ON MOTIVATION AND SEX TO CRIMINAL ACTS. THE CRIME SCENE INTERPRETATION IS DISCUSSED FROM A PERSPECTIVE WHICH REVEALS THE OFFENDER'S PSYCHOLOGY. A GENERAL DEFINITION OF SEX AND THE WAYS IN WHICH IT MANIFESTS ITSELF WERE OFFERED, INCLUDING THE ENVIRONMENTAL INFLUENCES ON BOTH HETEROSEXUAL AND HOMOSEXUAL DEVELOPMENT. THE NATURE OF AGGRESSION AND PASSIVITY ARE THEN DISCUSSED IN PREPARATION FOR THE COMPLETE PICTURE OF THE PSYCHOSEXUAL UNDERPINNINGS OF CRIMINALITY. INDIVIDUAL CHAPTERS DETAIL COMMON AND DANGEROUS SEX OFFENSES, SEX FANTASIES AND DREAMS, SADISM, MASOCHISM, SEX SYMBOLISM, AND SEXUAL FETISHES. A CHAPTER ON PORNOGRAPHY AND SEX CLUBS DEMONSTRATES THE IMPORTANCE OF THESE AREAS BOTH BECAUSE THEY PROVIDE AN AVENUE OF SEXUAL EXPRESSION SHORT OF CRIMINAL BEHAVIOR AND BECAUSE PERSONS MAY EMERGE AS OFFENDERS FROM THESE SUBCULTURES. THE CHAPTER ON HOMOSEXUALLITY EMPHASIZES THE NEED FOR LAW ENFORCEMENT OFFICERS TO RECOGNIZE THE EXISTENCE OF MANY HOMOSEXUALS IN SOCIETY AND TO FACE HOMOSEXUALS AND HOMOSEXUALITY IN AN INFORMED, UNBIASED MANNER. FINALLY, THE THEORETICAL AND PRACTICAL CONSIDERATIONS IN THE STUDY OF SEX OFFENSES ARE BROUGHT TOGETHER, PROVIDING AN ECLECTIC RANGE OF CRIMINAL INVESTIGATION APPROACHES. ILLUSTRATIONS, A BIBLIOGRAPHY, AND AN INDEX ARE PROVIDED. (AUTHOR ABSTRACT MODIFIED--MRK)