This report examines evidence-based programs and strategies that have been found to be effective at reducing youth crime and violence. An "evidence-based practice" is one that has been subjected to rigorous scientific study using experimental or quasi-experimental methods. This report examines the advantages and disadvantages of the two types of evidence-based practices: brand name programs and strategies. Brand name programs and strategies are very different. Strategies are general approaches to reducing crime and violence, while brand name programs are ones that have been developed by a single investigator or team over a number of years, and have been proven effective through rigorous scientific study and careful replication. This report is the result of a project developed to give service providers in California an accurate and up-to-date list of evidence based crime and violence prevention and intervention practices that have been found to be effective in identifying appropriate programs, strategies, and principles of implementation for the particular needs and settings of individual communities. The report includes information on how the list of evidence-based practices was created, as well as categories of evidence-based practices that include: proven programs, proven strategies, promising programs, ineffective programs and strategies, and principles of effective implementation. Appendixes