"Traditional law enforcement techniques historically have focused on the apprehension and prosecution of violent offenders 'after' violent crimes are committed. When police are given information that someone may potentially commit a crime or become violent in the future, their responsibilities, authorities, and available investigative tools are suddenly less clear. This guide is about threat assessment and management, or stated another way, 'how law enforcement officers and others may identify, assess, and manage the risk of future, planned violence'. This task is a complex and nuanced one. Published research about intended violence and its perpetrators, along with knowledge and experience derived from previous cases, are applied to the facts and circumstances of each case. In other words, there is a lot to think about. The FBI Behavioral Analysis Unit (BAU) held a symposium in mid-2015, bringing together academic researchers, mental health experts, and law enforcement practitioners of threat assessment to discuss the active shooter phenomenon. Specifically, symposium participants focused on prevention strategies with regard to this crime problem. By far the most valuable prevention strategy identified was the threat assessment and management team. The good news is that every organization and community has the potential to stand up or access such a team. The intent of this publication is, therefore, to provide desperately needed guidance on making this a reality for every community based upon a consensus of recommendations in an evolving field. Recommendations are offered about this process in very practical terms. It is not intended as an academic textbook but rather as a hands-on guide for novice and experienced threat assessment practitioners alike."