Part I, dealing with general legal principles in criminal cases, covers the management of criminal investigations, the elements of proof of a crime, basic principles of the common law of evidence, and basic rules of constitutional evidence. Part II addresses the various methods and techniques of conducting a criminal investigation, covering reactive investigations of crimes already committed and proactive investigations of ongoing criminal activity. Proactive investigations address street stops and roadblocks, the use of informers and undercover agents, and aural and visual surveillance. The use of these methods is examined for white collar crime, organized crime and political crime. Also considered is the preliminary investigation of a case which is usually conducted at the crime scene shortly after receipt of the initial report of the criminal incident. Part III focuses on the presentation of evidence in court proceedings and the testimony of investigator witnesses who authenticate physical evidence, testify concerning their investigations, and sometimes act as expert witnesses. Figures, chapter footnotes, and subject index