WASHINGTON — The Justice Department is creating a unit to fight domestic terrorism at a time when the threat of violent extremism has increased, a top official said on Tuesday.
The number of F.B.I. investigations of suspects accused of domestic extremism has more than doubled since the spring of 2020, the head of the department’s national security division, Matthew G. Olsen, said in testimony before the Senate Judiciary Committee.
The national security division has a counterterrorism team, Mr. Olsen added, but a group of lawyers will now be dedicated to the domestic threat and ensure that cases will be “handled properly and effectively coordinated” across the agency and federal law enforcement.
The move is in keeping with Attorney General Merrick B. Garland’s vow to prioritize combating domestic extremism. It comes as the Justice Department investigates the Jan. 6 attack on the Capitol, an assault that underscores the resurgence of domestic extremism driven in part by the baseless perception that the 2020 election was marred by election fraud.
Last year, the Biden administration unveiled a national strategy to tackle domestic extremism, which called for preventing recruitment by extremist groups and bolstering information sharing across law enforcement.
In its budget proposal this spring, the Justice Department requested an additional $101 million to address domestic terrorism, including $45 million for the F.B.I. and $40 million that federal prosecutors can use to manage their increasing domestic terrorism caseloads. But Congress has not yet passed its annual appropriations bill, so no agency funding requests have been granted.
Political events will continue to drive the threat of violence in 2022, Jill Sanborn, the executive assistant director of the F.B.I.’s national security branch, told the Senate panel.
The two most dangerous types of domestic extremists, Ms. Sanborn said, are driven either by racial or ethnic beliefs, oftentimes “advocating for the superiority of the white race,” or by antigovernment sentiment from members of militia or anarchist groups.
Racially motivated extremists were the primary source of lethal domestic extremist attacks in 2018 and 2019, according to F.B.I. data. But in 2020, militia and anarchist groups were responsible for three of the four lethal domestic extremist attacks.
Once considered a lesser threat, antigovernment extremists have become “commensurate with” racially motivated extremists, foreign homegrown terrorists and militant groups like the Islamic State, Ms. Sanborn said. In identifying antigovernment extremism as an equal threat, the bureau can more comprehensively combat it.
Both Justice Department officials said that domestic extremism inquiries were more sensitive than foreign terrorism cases given that the First Amendment prohibits the government from opening criminal investigations into Americans because of their beliefs.
Senator Richard Blumenthal, Democrat of Connecticut, highlighted that dilemma, asking the officials about the role that social media played in radicalizing individuals and allowing them to plan and promote activities like the rally that preceded the assault on the Capitol.
Online platforms fueled the rise of groups “responsible for several hate-related murders,” Mr. Blumenthal said. “Facebook promised to stop these violent extremist organizations and ban their groups. Instead, according to Facebook’s own researchers, the company failed to recognize the magnitude of the threat and take appropriate action.”
Mr. Olsen said that even as intelligence agencies had concluded that social media has allowed violent extremists to spread information with more speed and reach, the Justice Department could not simply investigate people for promoting a violent ideology online.
“Espousing ideology, hateful ideology, is protected by the First Amendment, generally speaking,” Mr. Olsen said.
Mr. Blumenthal singled out a handful of groups, including the Atomwaffen Division, a small paramilitary neo-Nazi group that has disseminated violent messaging on social media.
In February 2020, federal prosecutors charged five people tied to the group with working to intimidate and harass journalists, a member of President Donald J. Trump’s cabinet, a university and a church.
On Tuesday, the Justice Department announced that a Washington man associated with the group was sentenced to seven years in prison for his role in that plot.