The ethics of policing currently neglects to provide a framework for analysing the morality of deliberate inactions to prevent harm, even though these are often adopted tactically by police as a means of preventing greater harms. In this paper we argue (a) that police have special moral obligations to prevent harm, grounded both in a contractarian account of police legitimacy and in the interpersonal morality of associations and (b) that police are morally culpable for failures to fulfil these special obligations (...) when these are neither proportionate nor necessary to the prevention of greater crime-related harms. Our claims have implications both for the morality of policing and for its regulation and governance under human rights legislation, which we argue should be reformed so as to recognise police culpability not only for inflictions of harm, but also for failures to prevent it. (shrink)