This guide provides an overview of the key data elements, types of study designs, and the questions to consider when assessing and documenting prosecutor-led diversion program efficacy. Agencies can use the findings from well-designed, rigorous evaluation endeavors to inform major decisions like program operations and how to improve services. For example, a well-designed study can inform programmatic details like changing diversion conditions, reconfiguring eligibility criteria, or even shifting resources to another more promising program.