Searching for an collecting physical evidence at crime scenes and interviewing witnesses are examined as basic aspects of investigation. Basic investigative leads are presented in detail to develop an investigative system in which the crime and its circumstances are the key events. Eyewitnesses and the corroborating circumstances of motive, opportunity, and modus operandi are discussed in detail. Laboratory services, other scientific aids, surveillance, sources of information, police intelligence, and interrogation are presented as legal and scientific procedures with new methods based on reasonableness and empirical procedure. Coverage includes all aspects of the investigative function from preliminary investigation to the preparation of the case for review by the prosecutor. Police apprehension, continuing investigation, and case focusing are discussed as major components of this function. The concept of developing negative evidence as a means of blocking common defenses is fully explored. Scrupulous accuracy in reporting and affirming investigative actions are established as guidelines to dispel allegations of unlawful activity in the collection of evidence. The final chapter examine investigation of major crimes, including violent crime, homicides and assaults, nonstranger violence, forcible rape, child sexual and physical abuse and exploitation, robbery, terrorism, arson and bombings, narcotics offenses, theft, burglary, fraud, and conspiracy and white-collar crime. Chapter references, review, and assignments; index; and a 15-item selected bibliography.