Former Proud Boys leader Enrique Tarrio was convicted on Thursday of orchestrating a plot for members of his far-right extremist group to attack the U.S. Capitol in a desperate bid to keep Donald Trump in power after the Republican lost the 2020 presidential election.

Three other members of the group were also convicted of seditious conspiracy Thursday; jurors did not reach a decision on another defendant, though he was found guilty on several other charges. 

A jury in Washington, D.C., found Tarrio guilty of seditious conspiracy after hearing from dozens of witnesses over more than three months in one of the most serious cases brought in the stunning attack that unfolded on Jan. 6, 2021, as the world watched on live TV.

It’s a significant milestone for the Justice Department, which has now secured seditious conspiracy convictions against the leaders of two major extremist groups prosecutors say were intent on keeping Democrat Joe Biden out of the White House at all costs.

"Today's verdict makes clear that the Justice Department will do everything in its power to defend the American people and American democracy," Attorney General Merrick Garland said at a press conference later Thursday. 

"Since the Jan. 6 attack, the Justice Department has conducted one of the largest, most complex and most resource intensive investigations in our history," he continued, adding: "Our work will continue."

"At my Senate confirmation hearing just over a month after Jan. 6, I promised that the Justice Department would do everything in its power to hold accountable those responsible for the heinous attack that sought to disrupt a cornerstone of our democracy, the peaceful transfer of power to a newly elected government," Garland said. "And, as I have said repeatedly, the department will conduct all of its work in a manner that adheres to the rule of law, and honors our obligations to protect the civil rights and civil liberties of everyone in this country."

"Today's verdict is another example of our steadfast commitment to keeping those promises," Garland added. "The Justice Department will never stop working to defend the democracy to which all Americans are entitled."

The charge carries a prison sentence of up to 20 years.

Tarrio was a top target of what has become the largest Justice Department investigation in American history. He led the neo-fascist group — known for street fights with left-wing activists — when Trump infamously told the Proud Boys to “stand back and stand by” during his first debate with Biden.

Tarrio wasn’t in Washington on Jan. 6, because he had been arrested two days earlier in a separate case and ordered out of the capital city. But prosecutors said he organized and directed the attack by Proud Boys who stormed the Capitol that day.

Prosecutors told jurors the group viewed itself as “Trump’s army” and was prepared for “all-out war” to stop Biden from becoming president.

The Proud Boys were “lined up behind Donald Trump and willing to commit violence on his behalf,” prosecutor Conor Mulroe said in his closing argument.

The backbone of the government’s case was hundreds of messages exchanged by Proud Boys in the days leading up to Jan. 6 that show the far-right extremist group peddling Trump’s false claims of a stolen election and trading fears over what would happen when Biden took office.

As Proud Boys swarmed the Capitol, Tarrio cheered them on from afar, writing on social media: “Do what must be done.” In a Proud Boys encrypted group chat later that day someone asked what they should do next. Tarrio responded: “Do it again.”

“Make no mistake,” Tarrio wrote in another message. “We did this.”

Defense lawyers denied there was any plot to attack the Capitol or stop Congress’ certification of Biden’s win. A lawyer for Tarrio sought to push the blame onto Trump, arguing the former president incited the pro-Trump mob’s attack when he urged the crowd near the White House to “fight like hell.”

“It was Donald Trump’s words. It was his motivation. It was his anger that caused what occurred on January 6th in your beautiful and amazing city,” attorney Nayib Hassan said in his final appeal to jurors. “It was not Enrique Tarrio. They want to use Enrique Tarrio as a scapegoat for Donald J. Trump and those in power.”

Tarrio, a Miami resident, was charged and tried with four other Proud Boys: Ethan Nordean, Joseph Biggs, Zachary Rehl and Dominic Pezzola. Nordean, of Auburn, Washington, was a Proud Boys chapter leader. Rehl led a group chapter in Philadelphia. Biggs, of Ormond Beach, Florida, was a self-described Proud Boys organizer. Pezzola was a group member from Rochester, New York.

Nordean, Biggs and Rehl were also convicted of seditious conspiracy, in addition to other charges. The jurors did not return a verdict on Pezzola for the seditious conspiracy charge, but he was convicted of other charges, including obstruction of Congress.

The Justice Department hadn’t tried a seditious conspiracy case in a decade before a jury convicted another extremist group leader, Oath Keepers founder Stewart Rhodes, of the Civil War-era charge last year.

Over the course of two Oath Keepers trials, Rhodes and five other members were convicted of seditious conspiracy for what prosecutors said was a separate plot to forcibly halt the transfer of presidential power from Trump to Biden. Three defendants were acquitted of the sedition charge, but convicted of obstructing Congress’ certification of Biden’s electoral victory.

The Justice Department has yet to disclose how much prison time it will seek when the Oath Keepers are sentenced next month.