Preventive aims of the police in the area of juvenile crime control extend beyond prevention of actual criminal offenses to threats to the status quo from juveniles bent on radical modification of society. The police strategy involves collecting data on persons and places potentially useful in averting crisis situations and promoting a positive attitude of the public toward the police and the state. Although concepts of juvenile police vary from State to State, all notions of the juvenile police entail patrol and criminal investigative levels, as well as regular visits to certain places to contact juveniles and to gather information. In Bremen, officers visit discotheques, maintain a good rapport with youths, and supply them with educational films. In other cities, police start youth clubs to facilitate personal contact with juveniles. Information is gathered in all the places juveniles typically spend their leisure hours. In their omnipresent observation of juvenile activities, the police seek to expand their control to ever broader sectors of the population and to influence directly the development of the younger generation. The comprehensive activities of the juvenile police have met with opposition in some cities, but the police have only reacted by coordinating their efforts with those of social organizations and agencies. A 34-item bibliography is supplied.