Little empirical study had been done to confirm or refute the effectiveness of incarceration in reducing crime rates when America began its historic reliance on prisons in the 1970s. Today, conversely, policymakers are faced with a large, complex, and sometimes contradictory body of research. This paper seeks to help officials make sense of this information and offers an up-to-date understanding of what works best. It also examines research on several of the other factors that might be developed as part of an expanded notion of public safety. Informed by this more inclusive understanding of current research, it suggests that effective public safety strategies should move away from an exclusive focus on incarceration to embrace other factors associated with low crime rates in a more comprehensive policy framework for safeguarding citizens.