In the important article by David Weisburd, David Farrington, and Charlotte Gill (2017, this issue), based on a systematic review of 118 separate systematic reviews, the authors and their extensive research team have assembled the most compelling evidence to date that crime prevention and correctional programs work, and they often work extremely well. In fact, an amazing array of different approaches, including developmental and social prevention, community interventions, situational prevention, policing, sentencing/deterrence policies, correctional programs, and drug treatment, have surprisingly large effects on crime. Not only can we say that crime prevention and treatment “work,” we can say that many types of interventions have been shown to reduce crime or related problems by 50% or more, based on odds ratios derived from the average standardized effect size for each systematic review included in the seven review areas. These substantial impacts should have policy makers sitting up and taking notice especially because they are based on the result of analysis of thousands of primary evaluations.