Every year people with ties to a variety of extreme movements and causes kill people in the United States; the ADL Center on Extremism tracks these murders. Extremists regularly commit murders in the service of their ideology, in the service of a group or gang they may belong to, or while engaging in traditional, non-ideological criminal activities.
In 2021, domestic extremists killed at least 29 people in the United States, in 19 separate incidents. This represents a modest increase from the 23 extremist-related murders documented in 2020 but is far lower than the number of murders committed in any of the five years prior (which ranged from 45 to 78).
The 2021 murder totals were low primarily because no high-casualty extremist-related shooting spree occurred this past year. Such sprees are the main contributor to high murder totals.
Most of the murders (26 of 29) were committed by right-wing extremists, which is usually the case. However, two killings were committed by Black nationalists and one by an Islamist extremist—the latter being the first such killing since 2018.
Most of the 2021 murders were committed by people associated with longstanding extremist movements, such as white supremacy and the sovereign citizen movement. However, 2021 continued the trend of recent years of seeing some murders from newer types of extremism, including QAnon adherents, people associated with the toxic masculinity subculture of the “manosphere” and anti-vaccination extremists.
White supremacists killed more people in 2021 than any other type of extremist, though not an outright majority, as is often the case. An in-depth look at white supremacist killings over the past 10 years demonstrates the dangers posed by alt right white supremacists and white supremacist prison gangs.