After a trial lasting several months, a jury in Washington on Thursday handed the Justice Department a major victory, reaching a verdict in the Proud Boys Jan. 6 seditious conspiracy case.
Proud Boys leader Enrique Tarrio was convicted of seditious conspiracy for his role in the Jan. 6 attack on the Capitol.
Overall, Tarrio and Ethan Nordean, Joe Biggs, Zachary Rehl were found guilty of seditious conspiracy, conspiracy to obstruct the certification of the 2020 election, actual obstruction of the certification, conspiracy to prevent officers from performing their duties, obstruction of law enforcement during civil disorder and aiding and abetting in destruction of government property.
The Proud Boys leaders were acquitted charges they assaulted, impeded or resisted officers.
Those convicted face potentially decades in prison.
After deliberations continued for a few hours on the seditious conspiracy charge against Dominic Pezzola, he was found not guilty.
The jury was unable to reach a verdict for Pezzola on a count of conspiracy to obstruct an official proceeding.
Judge Timothy Kelly declared a mistrial on the remaining counts of assaulting, resisting or impeding officers.
Pezzola, who went by the nickname Spaz, admitted to the most violent conduct of the group when he testified that he used a stolen police riot shield to break through a window, allowing rioters to breach the building.
Earlier Thursday, he was convicted of robbery of U.S. government property.
Asked by his attorney why he decided to take the stand, Pezzola said, "to take responsibility" for what he did on Jan. 6 and explain that his co-defendants were not involved in many of his actions.
Tarrio was not present in Washington on Jan. 6 after his arrest on separate charges just days before. Prosecutors argued he directed his troops remotely with messages about revolution and telling them "don’t f---ing leave" after the building was breached that afternoon.
He was accused of orchestrating a fighting force with a group they called the "Ministry of Self Defense" comprised of dedicated Proud Boys and top leaders.
Tarrio's conviction follows the case of Stewart Rhodes, leader of another far-right group called Oath Keepers, who was convicted of seditious conspiracy for his role in the events of Jan. 6.
Video of the two ringleaders meeting in a Washington parking garage on the eve of Jan. 6 was part of the volumes of footage obtained by the Justice Department in the case.
Membership in the Proud Boys surged after then-President Donald Trump told the group to "stand back and stand by" during a 2020 presidential debate. Tarrio's attorneys blamed Trump for encouraging and revving up the crowd that ultimately broke into the Capitol.
The case is a win for authorities pursuing the hundreds of rioters who breached the Capitol. More than 1,000 arrests have been made in connection with Jan. 6, according to the Justice Department.
"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 in a statement, adding, "our work will continue."
Thursday was the seventh day of deliberations during which jurors asked multiple questions.
With dozens of witnesses and mountains of video and social media evidence, the Proud Boys trial has been the longest to date in the Justice Department's pursuit of Capitol rioters.
Since jury selection began in December, the case has dragged on with bitter arguments, frequent objections and mistrial motions. At times, Judge Kelly lost his temper and admonished the lawyers for interrupting or seeming to ignore his directions.
The Proud Boys insisted there were no plans to attack the Capitol and sought to cast themselves as nothing more than a hard-charging social club in which partying, drinking and exchanging crude jokes went along with attending political protests.
The group also describes themselves as "Western chauvinists," an unapologetic brand of fervent nationalism.
Prosecutors emphasized to the jury that the Proud Boys did not need to have detailed -- or successful -- plans to be found guilty. The conspiracy allegations hinged on their mutual understanding to oppose the government by force.
ABC News' Alexander Mallin contributed to this report.