This chapter begins by reflecting on the development and complexities of evidence-based policing. Whilst a hugely popular term, the levels of traction it has had within policing have met a decidedly mixed opinion. Too often the subject of definitional or methodological disputes, not to mention one of scope, critics argue it is often too focussed upon the transactional rather than transformative change. The chapter introduces the concept of evidence-based oversight as a broader more strategic complementary approach anchored to the work of the Police and Crime Commissioners (PCC) in England and Wales. This is demonstrated through the work of a research team that was moved from the police into the office of the PCC.