Evidence-based policing has widespread appeal. It calls for a shift from ways of working that are led by experience to that which is informed by the best available research evidence. Yet research evidence can, of course, take many forms and be of varying quality. In this chapter we consider the main sources of research evidence available to support decision-making in the crime prevention field. We begin by discussing four main sources of research evidence: practitioner reports, primary evaluation studies, systematic reviews, and reviews of reviews. We then focus on a sample of systematic reviews of single crime prevention interventions and, using the EMMIE framework (Johnson, Tilley and Bowers, 2015), we explore the extent to which these reviews adequately report information on the Effect of intervention, the Mechanisms through which interventions are believed to work, Moderators that may influence the impact of intervention, Implementation issues that may impede or facilitate the intervention, and the Economic costs of interventions. Based on this exercise and similar efforts to review the evidence base for crime prevention, we next outline five features that we argue increase the value of evidence reviews in support of crime prevention. Finally, we discuss some practical steps to increase the likelihood of future evidence reviews incorporating these features.