Public security has become an increasingly important political issue in Brazil since the end of military rule in 1985. Increasing levels of violent crime have led to various initiatives to reform the public security system, and especially the police. This article looks at three reforms intended to increase the accountability of the police to the public: police ombudsmen, community policing, and Public Ministry oversight of police investigations. Drawing from research in the Brazilian northeast and national studies, it argues that so far, these reforms have had less impact than expected. This is due in part to organisational characteristics of the police, and specifically their combination of insulation and vulnerability to political manipulation.