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.


PHE.Gov Preparedness Section: Click here for the Incorporating Active Shooter Incident Planning into Healthcare Facility Emergency Operations Plans

HIPAA covered entities and their business associates should be aware of the ways in which patient information may be shared under the HIPAA Privacy Rule in an emergncy situation

Active Assailant- 2 minute drill: A local hospital shares their active shooter response protocol

The Advanced Law Enforcement Rapid Response Training (ALERRT) Center at Texas State University. In 2013, ALERRT was named the National Standard in Active Shooter Response Training by the FBI

ACEP president calls for improved emergency response measures after Orlando shooting: Video

This is a fact sheet for the U.S. Department of Homeland Security’s Active Shooter Preparedness Program.


Managing your distress after an active shooting

Learn about who is most at risk for emotional distress from incidents of mass violence and where to find disaster-related resources

Crisis Counseling Assistance and Training Program helps individuals and communities recover from the effects of natural and human-caused disasters through community outreach and psycho-educational services

Discussion paper: Health and Medical Response to Active Shooter and Bombing Events

VIDEO – RUN.HIDE.FIGHT –  Surviving an Active Shooter Event (Ready Houston)

Active Shooter Response in a Healthcare Setting (law enforcement tactics and integrated medical and mental health response)– Federal Bureau of Investigation


Case Studies / After Action Reports – Lessons Learned:

1. Las Vegas Mass Shooting – Nevada Hospital Association

2. Pulse Nightclub: Rescue, Response, and Resilience – A critical incident review of the Orlando public safety response to the attack on Pulse nightclub – Community Oriented Policing Services (COPS), US Department of Justice

3. Sandy Hook Elementary Shooting After Action Report – Connecticut State Police

Other helpful links:

Everbridge has amassed a large collection of webinars, blogs, and white papers regarding active shooter preparedness.

Resource Collection: Active Shooter Incidents -California First Coalition

FBI Active Shooter Resources List

Planning and Response to an Active Shooter (2015) – Interagency Security Committee

Journal of Emergency Medical Services: 2018 article. New-standard-to-keep-communities-safe-from-active-shooters-and-other-threats

National Fire Protection: April 2018 article– Standard for an Active Shooter / Hostile Event Response Program