Community policing is one of the more significant recent developments in policing and the notion has been widely discussed and applied around the world. This thesis examines its various conceptions as discussed in the literature and in practice, with particular emphasis being given to the role of trust between police and citizens in this context. The investigation adopts a constructivist and qualitative comparative analysis based in two countries: Mexico and the UK (with two case studies in each country) and with data primarily collected through interviews with samples of police and citizens. Key findings are that: The variety of conceptions about community policing highlight the complex nature of the notion and the many factors shaping its varied practices. Police assumptions as to what constitutes good practice in community policing and what success might look like, deserve to be re-examined. The social constructions that police and citizens hold about community policing provide valuable sources of insight which challenge some of the conventional understandings regarding policing priorities. Trust is a vital ingredient for successful community policing and needs to be based as much on the police trusting citizens and communities as the other way round.