A comprehensive resource of active shooter and mass shooting facts and statistics.
Active shooter and mass shooting incidents have become more common in the United States in recent years, with some perpetrators openly expressing their intent to inflict large numbers of casualties. This resource provides a comprehensive overview of active shooter and mass shooting facts and statistics, as well as guidance on how to respond if such an incident occurs.
Active Shooter and Mass Shooting Facts
Active shooter incidents can occur anywhere and at any time, knowing some key active shooter facts and statistics will help you better prepare and could potentially save your life.
Active Shooter Definition
The FBI defines an active shooter as one or more individuals actively engaged in killing or attempting to kill people in a populated area. Implicit in this definition is the shooter’s use of a firearm. The active aspect of the definition inherently implies the ongoing nature of an incident, and thus the potential for the response to affect the outcome.
Most U.S. federal government agencies define an active shooter as “an individual actively engaged in killing or attempting to kill people in a confined and populated area.”
Total Number of Active Shooter Incidents
For the period 2017–2021, active shooter incident data reveals an upward trend: the number of active shooter incidents identified in 2021 represents a 52.5% increase from 2020 and a 96.8% increase from 2017. From 2017 to 2021 the annual amount of active shooter incidents is as follows:
Across the 61 active shooter incidents in 2021, two law enforcement officers were killed, and five law enforcement officers were wounded. The overall total for law enforcement officers killed and wounded (seven) is equal to the number killed and wounded in 2017.76 Those are the lowest figures in five years (2017–2021).
Most Popular Month for Active Shooter Incidents / Mass Shootings:
In 2020 and 2021, the Month of June had the highest number of active shooter/mass shooting incidents. Whereas, December had the least amount of active shooter incidents. Below is a breakdown of the number of active shooter incidents by month in 2021:
States with the Most Active Shooter Incidents / Mass Shootings
In 2021, there were 61 active shooter incidents across 30 states. California had the most mass shootings in 2021 with six total incidents. Georgia and Texas had the second most mass shootings in 2021 with five incidents each. Colorado and Florida tied for 3rd with a total of four mass shootings in 2021.
Deadliest Active Shooter Incidents in United States History
The following active shooter incidents are the deadliest to have occurred in modern U.S. history (1949 to present). If the shooter was killed or died by suicide during the incident, that death is not included in the total.
October 1, 2017 - 58 killed, 500+ injured Mandalay Bay Shooting (Las Vegas, Nevada)
In most cases, the active shooter will use a firearm. In rare cases, the active shooter may use other weapons and/or even improved explosive devices that cause more injuries and act as an impediment to law enforcement and emergency responders. Some of the improvised explosive devices are homemade and may detonate immediately or may have delayed fuses. No attempt should be made to go near or handle these devices.