Introduction

British policing is in crisis. Amongst a range of competing, diverse and progressive perspectives on how policing might be improved, evidence-based policing (‘EBP’) is winning institutional support and state patronage. EBP has come to monopolise how British policing is thought about by a range of actors, and its core ideas are becoming institutionalised despite their contestability. Two versions of EBP are described that are discoverable in the academic literature—the purist and realist models. A short description of how and where EBP has come to prominence in British policing is provided. Using literatures drawn from outside of EBP, the chapter provides a rationale for the book, setting out why the growing hegemonic position of EBP in British policing is potentially problematic and  requires further scrutiny. The chapter also provides an outline of how the rest of the book is structured and presented.