The term “active attack” is used to refer to any event in which an individual or individuals are attempting a mass murder. This could include the use of firearms, explosives, vehicle attacks, or any other weapon to inflict harm on a large number of people.

The agreed-upon definition of an “active shooter” by US government agencies (including the White House, US Department of Justice, FBI, US Department of Education, US Department of Homeland Security, and Federal Emergency Management Agency) is “an individual actively engaged in killing or attempting to kill people in a confined and populated area.”  In most cases, active shooters use firearms and there is no pattern or method to their selection of victims.

Active shooter situations are unpredictable and evolve quickly. Because active shooter situations are often over within 10 to 15 minutes, before law enforcement arrives on the scene, individuals must be prepared both mentally and physically to deal with an active shooter situation. In most cases, active shooters use firearms(s) and there is no pattern or method to their selection of victims.

The following terms are also use: Active Killer; Violent Intruder; and Active Assailant.

Following are quick links to resources to assist in your efforts. These are listed for informational purposes only and do not imply endorsement by the Network.




Case Studies / After Action Reports – Lessons Learned:

Other Helpful Links