Youth violence and delinquency are problems that continue to challenge many communities across the U.S. For over a decade, Pennsylvania has been a national leader in confronting youth problem behaviors in a progressive and proactive fashion, investing heavily in supporting local community prevention coalitions and the use of proven-effective models for preventing youth violence and aggression, delinquency and youth substance abuse. Since 1998, the Pennsylvania Commission on Crime and Delinquency (PCCD) has invested over $60 million in implementing more than 140 effective prevention programs in more than 100 Pennsylvania communities. Community priorities are guided by local data based on a public health model of reducing known risk factors associated with violence and delinquency and promoting positive youth development. To further support the positive impact of this investment, PCCD has also made a commitment to providing training and technical assistance to these communities to ensure that the programs are implemented with the highest quality and fidelity, and that thoughtful planning is undertaken to ensure that programs are sustained beyond PCCD grant funding. This report details Pennsylvania's approach to effectively addressing juvenile crime. It presents case studies of model prevention programs being implemented throughout the Commonwealth through Pennsylvania Commission on Crime and Delinquency funding, and describes the positive outcomes being seen in these communities. An appendix provides information about programs funded through the Research-Based Programs Initiative: 1998-2007. (Contains 21 figures.)