The former chairman of the US right-wing group the Proud Boys, Enrique Tarrio, was arrested on Tuesday on a conspiracy charge for his alleged role in plotting the January 6, 2021, assault on the US Capitol.
He will make his initial appearance in a federal court in Florida on Tuesday afternoon, said Marlene Rodriguez, a spokeswoman for the US Attorney's Office in Miami.
Mr Tarrio is one of the most high-profile of more than 775 people criminally charged for their roles in the attack on the Capitol by supporters of the president at the time, Donald Trump.
Though he was not on the Capitol grounds on January 6, Mr Tarrio has been charged with helping plan and direct it.
Other members of the Proud Boys removed Mr Tarrio from their private chat rooms early on Tuesday after learning of his arrest, said a member of the group who asked for anonymity.
Eleven people affiliated with the Oath Keepers militia, including that group's founder, Stewart Rhodes, were charged in January with seditious conspiracy for their alleged roles in planning the attack.
Mr Tarrio was added as one of the accused to a case naming other Proud Boy members Ethan Nordean, Joseph Biggs, Charles Donohoe, Zachary Rehl and Dominic Pezzola.
That case is tentatively scheduled to go to trial on May 18.
A lawyer for Mr Tarrio did not immediately respond to a Reuters request for comment.
Police in Washington on January 4, 2021, arrested Mr Tarrio on destruction of property charges connected to the December 12, 2020, burning of a Black Lives Matter banner at a historic African-American church.
Mr Tarrio was released from custody on January 5, 2021, and ordered to stay out of the city as a condition of his release. He later served a four-month stint in jail for the charges.
Although Mr Tarrio did not storm the Capitol with some of the other Proud Boys, prosecutors say he nonetheless continued to direct and encourage his fellow Proud Boys members during the riots.
He also allegedly claimed credit for what happened on social media as well as in an encrypted chat room.
The former Proud Boys leader is charged with conspiring to obstruct an official proceeding, a fairly common felony charge that many Capitol rioters are facing. It can carry up to 20 years in prison on conviction.
Mr Rhodes, by contrast, is facing charges of seditious conspiracy, a less commonly seen serious felony offence that criminalises attempts to overthrow the government.
One of the 11 Oath Keepers accused in the case, Joshua James, pleaded guilty as part of a deal with prosecutors last week. The deal was a notable victory for the Justice Department, which hopes to secure similar convictions against other accused.
