This article considers the impact of a shared island on police governance, accountability and oversight. Having outlined a framework for conceptualising each of these terms, it provides a history of policing on the island and an overview of the current structures. It then turns its attention to what options exist for a shared island, from retention to mergers and the creation of new services. The intricacies of each are teased out, including both practical and political issues. It establishes how complex the issues are, and the ripple effects of slight changes. Ultimately the article argues that to ensure the legitimacy of the police and the effective achievement of policing and human rights goals, the creation of one or more new services, and the separation of state security, may be necessary.