The results suggest that some evidence-based programs can reduce crime, but others cannot. Economically attractive evidence-based options in three areas were found: adult corrections programs, juvenile corrections programs, and prevention. Per dollar of spending, several of the successful programs produced favorable returns on investment. Public policies incorporating these options can yield positive outcomes for Washington. The study indicates that if Washington successfully implements a moderate-to-aggressive portfolio of evidence-based options, a significant level of future prison construction can be avoided, taxpayers can save about $2 billion dollars, and crime rates can be reduced. Current long-term forecasts indicate that Washington State will need two new prisons by 2020 and possibly another prison by 2030. With the cost of a typical new prison about $250 million to build and $45 million a year to operate, the Washington State Legislature directed a study be conducted by the Washington State Institute for Public Policy to test whether evidence-based public policy options could: (1) lower the anticipated need to build new prisons, (2) reduce State and local fiscal costs of the criminal justice system, and (3) contribute to reduced crime rates. Exhibits and appendixes