This Handbook is one of the practical tools developed by UNODC to support countries in the implementation of the rule of law and the development of criminal justice reform. It aims to assist countries in their efforts to develop effective systems of oversight and accountability within their law enforcement authorities and enhance police integrity, and it addresses issues including enhancement of police integrity and the integrity of policing, dealing with complaints about policing (receipt, investigation and follow-up), setting policing priorities and encouraging policy input, including from outside the police, and “inviting” external review, including from independent actors.