This guide is intended for use by medical personnel, lawyers, members of national human rights institutions, or others who carry out preventive activities concerning the police or have the mandate to visit police stations. Members of national preventive mechanisms will be the primary users of this guide. The document is divided into three chapters: the first outlines the powers of the police and the importance of human rights in context, the second discusses how to conduct monitoring visits, and the third cites national and international standards for police detention.