The report's findings and recommendations are based on a nationwide survey of law enforcement agencies, personal interviews with key local law enforcement and community leaders, and site visits with police departments and local community members. Two general conclusions are drawn from the study. First, law enforcement agencies face multiple obstacles to creating community partnerships that focus on preventing crimes motivated by violent extremism. Second, some law enforcement agencies are engaged in promising practices that can cultivate trust between the police and the communities they serve. This trust can be the foundation for cooperation in addressing public-safety threats, including violent extremism. Based on this assessment's findings, recommendations are proposed for building trust between police and communities and for cooperation in preventing acts of violent extremists. Fourteen recommendations are addressed to local police agencies, suggesting how to organize, train, and apply police resources to strengthen cooperative interactions with a community composed of diverse races, ethnicities, and cultural values. Three recommendations deal specifically with police engagement with Muslim-American communities, which are at risk for profiling, discrimination, and negative stereotyping. Five recommendations provide guidance for how the Federal Government can assist local police-community partnerships against violent extremism through strategic funding and technical assistance.