Although the Bundeskriminalamt and other police organizations initiated many studies in the 1980's, most of those studies provided information for the police rather than about it. In contrast, these papers are about the police. The first group of articles consists of presentations of international criminologists at the 10th World Congress for Criminology in Hamburg in 1988. These papers show clearly that police effectiveness is now seen in a new context; the focus is on the relationship between the police and the public rather than on the issue of clearance rates. The police understand that their role is not only crime control but also attention to the comprehensive security needs and problems of the community. Therefore, police must consider victims as well as offenders and must establish a network of mutual trust and information exchange with the public.