A recent flyer distributed by the Mexico City police department, the Secretaría de Seguridad Pública del Distrito Federal (SSPDF), informs local residents about the possibilities and merits of citizen participation in security matters. In addition to providing information about the different activities of the citizen participation program it ends with the following disclaimer: This program is of public character. It is not conveyed nor promoted by any political party and its resources come from the taxes paid by all taxpayers. It is forbidden to use this program for political and electoral goals, for pecuniary rewards or any other purposes different from those established in the program. Anyone that will make an improper use of the program’s resources in the Federal District will be sanctioned according to the respective law and from the responsible authority (SSPDF 2009). This uneasy and contradictory relationship between citizen participation in security matters and the instrumentalization, or better put, appropriation, of the latter for private or political purposes is at the centre of this article. By drawing on the results of empirical fieldwork in Mexico City, this article takes a closer look at a local community policing program, the Policía de Barrio project, in order to demonstrate that contrary to the expectations of many Latin American policy makers, think tanks, NGOs and a growing number of related scholarly articles and books, community participation in security matters cannot be expected to function as a blueprint for improving citizen-police relations and the prevailing (in)security situation in contemporary urban Latin America (on the latter aspect, see IBRD 2008; Koonings/ Kruijt 2007; Rotker 2002). By confronting the official claims and objectives of the Policía de Barrio program, together with an analysis of how this community policing program operates in practice, this article argues that despite its claim for improving police-citizen relations and the security situation, the concrete practices of the Policía de Barrio are overdetermined by different socio-political features of the local context, such as clientelism, police corruption, and party politics. These components, therefore, render the contribution of this community policing effort for the sustainable improvement of local accountability, police efficiency and legitimacy unlikely.