According to the Active Shooter Incidents in the United States in 2021 report, casualty counts are higher for 2021 (243) when compared with 2020 (164), indicating a 48% increase. The casualties in 2021 represent the third-highest total casualty count over the last five years (2017–2021). 2021 saw the highest number of deaths (103) since 2017, a 171.1% increase from 2020 and above the average (92.3) for 2017–2020. There was an 11.1% increase in people wounded (140) in 2021 compared with 2020 (126), but below the average (253) for the period 2017–2020. 

For 2021, the FBI observed an emerging trend involving roving active shooters, specifically, shooters who shoot in multiple locations, either in one day or in various locations over several days. 

The 61 incidents in 2021 were carried out by 61 shooters. Sixty shooters were male, and one was female. Individual shooters carried out all the incidents. The age range of the shooters was 12 years old to 67 years old. Two shooters wore body armor. Thirty shooters were apprehended by law enforcement, 14 shooters were killed by law enforcement, four shooters were killed by armed citizens, one shooter was killed in a vehicle accident during a law enforcement pursuit, 11 shooters committed suicide, and one shooter remains at large. 

Commenting on the findings, former Assistant Secretary at the Department of Homeland Security Brian Harrell says, “There’s no doubt that society is becoming more violent every day. Would-be criminals and domestic terrorists will always use the path of least resistance, and often times soft targets and schools, are picked for this violence. While there will be calls for restricting guns, also at play here, is the fact that schools must invest in their campus security [to become] a ‘hard target.’ Administrators, teachers, students, and the law enforcement community must come together to embrace student security — or predators will find a way into our most sacred places. With school security events increasing across the country, schools should devote attention to the full spectrum of school safety, which encompasses prevention, protection and mitigation, and response and recovery.”