An empirical study of police shows how value conflicts of democratic society create conditions that undermine the capacity of police to respond to the rule of law. Data for the study were drawn from an examination of criminal law officials in a city of approximately 400,000 with a nonwhite population of about 30 percent. The gathering of data began in the summer of 1962 and extended into the summer of 1963. The city involved is reputed to have an exemplary criminal justice structure. Through a questionnaire and direct observation, patterns of police behavior were examined in a variety of areas of law enforcement, including traffic violations, prostitution, and narcotics. A sketch of the policeman's "working personality" is presented, along with a description of his operational environment and use of discretion. His use of informers is also treated. Police attitudes toward criminal law and views of the exclusionary rule are examined. Facts presented in the study were deemed accurate by all individuals questioned and observed, although there was not always agreement on interpretations given to the data. It is concluded that the tension between the operational goals of order, efficiency, and initiative on the one hand and the protection of the legal rights of individual citizens on the other constitutes the principle problem of police as a democratic legal organization. The appendix includes a brief survey of the character of the city studied, comparative data on the police, a history and organization of the offices of public defender and district attorney in La Loma County, California, and the questionnaire given to the police.