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. 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 PCCD funding, and describes the positive outcomes being seen in these communities. Programs Funded Through the Research-based Programs Initiative: 1998-2007 are appended. (Contains 21 figures and 6 footnotes.)