This document summarizes an open source best practices presentation for law enforcement personnel. It discusses the community source model for collaborative open source development between agencies. Examples of successful community source projects are provided, such as LEADR for law enforcement data sharing. Best practices that contribute to success include having formal governance, leadership buy-in, releasing code often, and vendor participation. Challenges that can kill a project are loss of leadership, lack of communication, and releases that are too slow. The presentation concludes with a discussion of attracting law enforcement to open source and standards that could enable further collaboration.