Challenges in the 21st-century United States have proven monumental for those charged with providing public safety. Due to the grim rate of evolving threats, innovative thinking, planning, responding, and recovering have been necessary since the attacks of 9/11. As such, the many disciplines within the first responder community have reinvented the ways in which they respond to emergency situations.

Among the emerging and increasing threat scenarios is the active shooter mass casualty situation, which a 2014 Federal Bureau of Investigation (FBI) study of 160 active shooter cases showed to be on the rise. Between 2000 and 2013, the rate of active shooter events rose from 6.4 to 16.4 incidents per year—leading to an overall average of 11.4 per year. If one considers that 70 percent of the incidents occurred in either commerce, business, or educational venues, it illustrates the challenge facing first responders. These types of locations are considered soft targets, and active shooter incidents exploit the extreme vulnerability of venues where members of the community traditionally feel safe. These attacks also exemplify the unpredictability of when or where the next incident might occur.