Governments facing high levels of crime and violence must act through their criminal justice systems to increase safety while delivering justice. To do this rigorously, governments need to improve their measurement tools. This paper examines the measurement tools employed today in two developing countries—Jamaica and the Dominican Republic— showing how existing data might be analyzed and presented more effectively. It is described that the many tactics used by police, prosecutors, and other institutions within the criminal justice system as falling under two broad strategies: (1) removing criminals from society, and (2) reducing the proximate causes of crime. All countries depend on some combination of these two strategies, but while governments tend to favor the first, the second usually produces greater crime reduction. This report demonstrates how improving five specific performance indicators can help governments reduce the proximate causes of crime, maximizing the contribution of criminal justice systems to public safety.