An overview of the U.S. welfare system considers the scope and types of welfare; welfare management, organization, and funding share; and eligibility for welfare. An analysis of agencies typically responsible for welfare fraud investigation identifies the problems encountered when welfare agency personnel assume responsibility for investigating welfare fraud; the use of police officers rather than welfare personnel for such investigations is recommended. The Los Angeles County experiment described used police officers to investigate welfare fraud; they were particularly effective in detecting and resolving cases that involved multiple or fictitious identities and forged documentation. The program evaluation concludes that the project constitutes a model program that has achieved significant results. Based upon the Los Angeles experience, the book provides guidelines for establishing and managing a police welfare fraud unit. Detection and investigation techniques are also described. They cover fraud indicators, investigation planning, recordkeeping, evidence, interrogation, criminalistics, public documents, and surveillance. Attention is also given to equipment, searches, arrests, fugitives, and response teams. The concluding section of the book presents guidelines for prosecution. 30-item bibliography and subject index.