This course focuses on the law enforcement professional's response to an active shooter/hostile threat event, including fundamental principles, technical aspects, and the critically important practice of integrating first responder resources. The course examines lessons learned using past events and statistical data. It also includes common definitions of active shooter/hostile threat events, principles of officer movement and contact, performance under stress, prevention of blue-on-blue situations, communication strategies, a tactical medicine overview, and more. The course provides a discussion of concepts and tactics that law enforcement professionals can share with family, friends, and the community, to make everyone safer during one of these increasingly more frequent threats to personal safety.