One lesson is the importance of conducting a comprehensive data analysis. Without comprehensive data on cost and outcomes for existing criminal justice operations, States are unable to develop policies that respond to the challenges they face. A second lesson is to engage diverse constituencies. Engaging county and city officials, criminal justice stakeholders, and treatment providers is critical to ensuring policies will improve cost and outcomes across the system. A Third lesson is the importance of focusing on the people most likely to reoffend. Spreading criminal justice resources equally across all risk levels does not maximize their impact. A fourth lesson is to reinvest in high-performing programs. A key component of the justice reinvestment strategy is the redirection of the savings and averted spending generated by new policies into strategies and programs proven to reduce recidivism and improve public safety. A fifth lesson is to strengthen community supervision. Current research points to the "Risk-Need Responsivity" model as the most effective way for corrections authorities to identify and prioritize individuals to receive appropriate interventions. This requires that the criminal justice system have a variety of community-based treatment responses that can address the variety of criminogenic needs of offenders. The sixth lesson is to incentivize performance. Incentive funding is most commonly used to encourage local authorities to use and improve community-based sanctions for individuals who might otherwise be returned to prison for violations of the conditions of their release. Criminal justice agencies must have confidence that when they produce positive outcomes, funding will be provided to sustain and even expand these efforts.