In a study from the FBI, titled Active Shooter Incidents: A 20-year Review, the agency looks at active shooter incidents in the U.S. between 200 and 2019. 

The agency looked at data from 333 incidents between 2000 and 2019. In those incidents, a total of 2,851 people died or were wounded, excluding the shooters. California was found to have more incidents than any other state (42 incidents) in the U.S. during this time period.

The FBI defines an active shooter incident as “one or more individuals actively engaged in killing or attempting to kill people in a populated area” using “one or more firearms,” in a situation that is ongoing in nature with the potential for the “response to affect the outcome.”

Of the 333 incidents, 345 shooters were involved in those incidents. According to the FBI, 119 took their own life and 150 were arrested by police; other outcomes include the shooter(s) being killed by police, killed by a citizen or not arrested at this time.

About 29% of the incidents happened at businesses that are open to pedestrian traffic; this includes places like retail stores or strip malls, office buildings, restaurants, etc. About 15% of the incidents happened in open spaces and 13% happened at K-12 schools.