WASHINGTON — Federal prosecutors are employing an unusual strategy to prove leaders of the far-right Proud Boys extremist group orchestrated a violent plot to keep President Joe Biden out of the White House, even though some of the defendants didn’t carry out the violence themselves.

As they wrap up their seditious conspiracy case, prosecutors are arguing that Proud Boys chief Enrique Tarrio and other leaders of the group handpicked and mobilized a loyal group of foot soldiers — or “tools” — to supply the force necessary to carry out their plot to stop the transfer of power from Donald Trump to President Joe Biden after the 2020 election.

These “tools” helped Proud Boys leaders overwhelm police, breach barricades, force the evacuation of the House and Senate chambers and disrupt the certification of Biden’s victory, prosecutors allege.

Defense attorneys have dismissed the “tools” theory as a novel, flawed concept with no legal foundation. They argue that the Justice Department is trying to unfairly hold their clients responsible for the violent actions of others in the crowd of Trump supporters. Tarrio, for example, wasn’t even in Washington on Jan. 6.

The seditious conspiracy trial, which started nearly two months ago, is one of the most serious cases to emerge from the Jan. 6 attack on the Capitol and comes as some conservatives continue to try to downplay the riot and push false narratives about what happened that day. Tarrio, who led the neofacist group as it became a force in mainstream Republican circles, is among the highest-profile defendants to stand trial yet and could face up to 20 years in prison if convicted of seditious conspiracy.

Seditious conspiracy — a rarely used charge from the Civil War-era — can be difficult to prove, especially when the plot was unsuccessful. And the group leaders on trial aren’t accused of engaging in violence themselves. Tarrio was arrested on separate charges two days before the riot.

Tarrio is on trial with Ethan Nordean of Auburn, Washington, who was a Proud Boys chapter president; Joseph Biggs of Ormond Beach, Florida, a self-described Proud Boys organizer; Zachary Rehl, who president of the Proud Boys chapter in Philadelphia; and Dominic Pezzola, a Proud Boy member from Rochester, New York.

Their trial could stretch into April. Prosecutors are expected to rest their case as soon as next week. Defense lawyers plan to present at least two weeks of testimony before jurors get the case.

The prosecution’s case hit a snag this week with the revelation that the government accidentally provided defense attorneys with sensitive messages from FBI agents. Testimony was suspended until next week as authorities searched the files for possible classified information.

The Justice Department presented a more conventional theory at the trial last year for Oath Keepers founder Stewart Rhodes, who was convicted of seditious conspiracy along with another leader of the antigovernment group. Oath Keepers members stockpiled guns at a Virginia hotel so they could shuttle them across the Potomac River into Washington if they were needed to support their plot to stop the transfer of power, prosecutors said. The weapons were never deployed.

In this case, prosecutors are trying to show that the Proud Boys used people as their weapons.

“The Oath Keepers had their rifles. The Proud Boys had their ‘real men,'” prosecutor Conor Mulroe has said.

Mulroe was referring to text messages that Proud Boys organizer Joseph Biggs sent to Tarrio weeks before the Jan. 6, 2021, attack at the Capitol. In a Dec. 19 text, Biggs told Tarrio that the Proud Boys have been recruiting “losers who wanna drink.”

“Let’s get radical and get real men,” Biggs added.

Randall Eliason, an adjunct professor at George Washington University Law School and former federal prosecutor, described prosecutors’ tools theory as “unusual but not remarkable.”

“It’s not something that comes up a lot, but there’s nothing controversial about the idea,” he said. “And the word ‘tools’ is kind of the perfect way to describe it. In other words, whether you use a battering ram to break down the door of the Capitol or whether you enlist a bunch of other people to help you break down the door to the Capitol, they’re all tools, right?”

Prosecutors this week publicly identified nearly two dozen Proud Boys members and associates they say served as “tools.” All but one of the 23 people named as “tools” have been publicly and separately charged with Capitol riot-related crimes.

An FBI agent narrated videos for jurors that show Proud Boys’ “tools” marching from the Washington Monument to the Capitol and clashing with police officers who were trying to hold off the mob of Trump supporters.

“Let’s go! This is what we came for!” Proud Boys member William Pepe shouted before taking down a police barricade.

Prosecutors argue the “tools” didn’t have to know the ultimate goal of the Proud Boys’ conspiracy to be part of it. Mulroe compared the concept to human “mules” unwittingly transporting drugs or money.

“The case is about the concerted efforts of a group of people, this group that the defendants called real men. And our position is that they weaponized these people,” the prosecutor said.

Before the trial started in January, U.S. District Judge Timothy Kelly ruled that prosecutors could present evidence to support their “tools” theory. The judge acknowledged it’s an “unusual” theory but said the actions of rioters who followed Proud Boys leaders to the Capitol can be relevant under certain circumstances.

Norman Pattis, an attorney for Biggs, said comparing Oath Keepers’ guns to Proud Boys followers is a “clumsy analogy.” Pattis also said he doesn’t know of any case in which prosecutors have been allowed to argue that “acts of third parties are the legal responsibility of criminal defendants absent some nexus other than mere proximity and shared political views.”

“There is nothing but rank and dangerous speculation supporting this theory,” he wrote in court papers, urging the judge to “reject such evidence as little more than an effort to make hindsight do the work of proof.”