The Justice Department has filed charges of seditious conspiracy against Stewart Rhodes, who is the founder of the Oath Keepers, and ten others in relation to their role in the riot at the U.S. Capitol on January 6, 2021.

The indictment accuses Rhodes and his co-conspirators of trying to "oppose by force the execution of the laws governing the transfer of presidential power."

Prosecutors cited a message Rhodes wrote using the messaging app Signal moments before the protestors breached the Capitol Building.

"All I see Trump doing is complaining. I see no intent by him to do anything," Rhodes allegedly wrote. "So the patriots are taking it into their own hands. They've had enough."

Rhodes has denied any wrongdoing. There is no evidence that he ever entered the U.S. Capitol building during the riot, but he was seen meeting with several of the defendants outside the building before they stormed the building during a joint session of Congress.

The charges mark a sharp escalation in the FBI's investigation into the riot. Over 700 people have been charged, and several have been sentenced for their roles in the riot. Most of those charges involve lesser crimes, including entering and remaining in a restricted building or grounds and obstructing an official government preceding.

"The charges against Stewart Rhodes send a strong message about the criminal conspiracy he was engaged in," Javed Ali, the former senior counterterrorism director at the National Security Council and a former FBI and DHS official, told ABC News. "While there is no crime of domestic terrorism under U.S. law, the seditious conspiracy charge that Rhodes and others will now face is one of dozens of crimes under the terrorism enhancement statute, which could boost the amount of years he and other defendants face if these cases go to trial and the U.S. government wins."

If convicted, the defendants face up to 20 years in prison.