A leader of the Proud Boys and four other members of the far-right group were indicted on sedition charges on Monday in connection with the January 6 assault on the US Capitol.
Henry “Enrique” Tarrio, 38, is already facing other charges related to the failed attempt by supporters of former president Donald Trump to block Democrat Joe Biden’s election victory.
A superseding indictment unveiled on Monday added the more serious charge of seditious conspiracy to the charges against Tarrio, the former “national chairman” of the Proud Boys, and the four other members.
Tarrio was arrested in Miami in March and is also charged with conspiracy to obstruct an official proceeding, obstruction of law enforcement, destruction of government property and other offenses.
More than 800 people have been arrested in connection with the storming of Congress by Trump supporters, according to the Justice Department, but only a handful face the charge of seditious conspiracy, which carries a sentence of up to 20 years in prison.
Stewart Rhodes, 56, founder of another far-right organisation, the Oath Keepers, has been charged with seditious conspiracy along with 10 other members of the group.
Three members of the Oath Keepers have pleaded guilty.
According to the superseding indictment, Tarrio was not in Washington on January 6 but he met with Rhodes on January 5 in an underground parking garage in Washington and was in contact with members of the Proud Boys who breached the Capitol.
Along with Tarrio, four other members of the Proud Boys — Dominic Pezzola, 44, Joseph Biggs, 38, Ethan Nordean, 31, and Zachary Rehl, 36 — were charged with seditious conspiracy in addition to their previous charges.
The indictment comes three days ahead of a public hearing by the House select committee investigating the storming of the US Capitol.
The committee is trying to see if Trump or members of his circle had a role in planning or encouraging the violent attack, and has subpoenaed advisors and aides to the former president.
The assault on the Capitol left at least five people dead and 140 police officers injured and followed a fiery speech by Trump to thousands of his supporters near the White House.
Trump was impeached for a historic second time by the House after the Capitol riot — he was charged with inciting an insurrection — but was acquitted by the Senate, where only seven members of his own Republican party voted against him.