F.B.I. agents and federal prosecutors are investigating Stewart Rhodes, the founder and leader of the Oath Keepers militia, for any role he might have played in the storming of the Capitol two months ago, according to court documents and a law enforcement official with knowledge of the matter.
While the inquiry is in its nascent stages, the official said, its existence shows that investigators appear to be targeting the senior leadership of the paramilitary group that Mr. Rhodes has run for more than a decade. If he were ultimately charged, it could amount to a crippling blow to the militia.
The Oath Keepers, who largely draw their members from the ranks of former military and law enforcement personnel, have from the start been a central focus of the sprawling investigation into the Capitol riot, which has led to charges against nearly 300 people. Eleven members of the group stand accused of a variety of crimes stemming from the siege, most prominently an alleged conspiracy reaching back to shortly after Election Day to break into the Capitol and interfere with Congress’s Jan. 6 certification of the Electoral College vote.
As three cases against his subordinates have moved through the courts, Mr. Rhodes, a former Army paratrooper, has been mentioned at least six times in legal filings as Person One, effectively putting him on notice that investigators are examining his conduct. Prosecutors have noted, for example, that two days before the Capitol attack, he issued a “call for action” on the Oath Keepers’ website, urging “all patriots who can be in D.C.” to “stand tall in support of President Trump’s fight to defeat the enemies foreign and domestic who are attempting a coup.”
In the same communiqué, Mr. Rhodes announced that the Oath Keepers would be sending “multiple volunteer security teams” to provide protection to “V.I.P.s” at events surrounding Mr. Trump’s speech and rally in Washington earlier on the day of the riot. The New York Times has identified a group of Oath Keepers who worked as security guards for Mr. Trump’s close ally and adviser Roger J. Stone Jr. at such events, and this week two of them — Roberto Minuta and Joshua A. James — were arrested in connection with the Capitol attack.
In court papers filed on Monday night, prosecutors significantly raised the stakes against Mr. Rhodes, saying that they now have evidence that he was in direct communication with some of the plot suspects before, during and after the assault on the Capitol. Prosecutors said they have recovered messages — batched together under the title “DC OP: Jan 6 21” — from the encrypted chatting app Signal connecting Mr. Rhodes to regional Oath Keepers leaders from around the country, including two who have been charged in the conspiracy case: Jessica M. Watkins of Ohio and Kelly Meggs of Florida.
In the Signal messages, prosecutors say, Mr. Rhodes can be seen assuring members of the group that “well-equipped Q.R.F.s” — or quick reaction forces — would be standing by outside Washington on Jan. 6 “in case of worst case scenarios.” Prosecutors also say that the chats show Mr. Rhodes monitoring events on the ground during the riot and, at one point, ordering a group of Oath Keepers to rally on the southeast steps of the Capitol, after which several members entered the building in what has been described as a military-style “stack.”
Prosecutors overseeing the investigation of Mr. Rhodes, who attended Yale Law School after his military service, have nonetheless struggled to make a case against him. The official with knowledge of the matter said his activities have so far have seemed to stay within the boundaries of the First Amendment.
Mr. Rhodes did not respond on Wednesday to messages seeking comment; he told The Washington Post that his group had “no plan to enter the Capitol.” A Justice Department spokesman declined to comment, as did an F.B.I. spokeswoman.
Still, even if no evidence can be found that Mr. Rhodes personally entered the Capitol, which would amount to clear proof of a crime, that does not preclude prosecutors from charging him as part of a larger conspiracy. In February, prosecutors filed a criminal complaint against Ryan Ashlock of Kansas on conspiracy charges, asserting that he was part of a group of Proud Boys who traveled to Washington to “stop, delay and hinder the congressional proceeding” on Jan. 6 even though he never entered the building.
Known for his distinctive black eye patch — the result of a gun accident — Mr. Rhodes has long been known to the F.B.I. and remains under investigation for a matter separate from the riot at the Capitol, a Justice Department official said. For years, he has earned a reputation as a leader of the right-wing “Patriot” movement, often spewing incendiary rhetoric to recruit and inspire militia members.
“As we have said consistently, we do not and will not tolerate violent extremists who use the guise of First Amendment-protected activity to wreak havoc and incite violence,” Christopher A. Wray, the F.B.I. director, said in a statement for the record before testifying to the Senate Judiciary Committee last week.
After gaining early experience in politics working for the libertarian Ron Paul, the former Republican congressman from Texas, Mr. Rhodes formed the Oath Keepers in 2009, just months after President Barack Obama took office. At a ceremony in Lexington, Mass., the site of a famous battle of the Revolutionary War, Mr. Rhodes said his plan was for members of the Oath Keepers to disobey certain illegal orders from the government and instead uphold their oath to the Constitution.
Throughout the Obama years, gathering momentum as a militia group, the Oath Keepers repeatedly inserted themselves into prominent public events. They turned up, for instance, in 2014 at a cattle ranch in Nevada after its owner, Cliven Bundy, engaged in an armed standoff with federal land management officials. That same year, members of the group went to Ferguson, Mo., in a self-appointed mission to protect local businesses from riots prompted by the death of Michael Brown, a Black man who was shot by the police.
After Mr. Trump was elected, Mr. Rhodes and the Oath Keepers seemed to pivot away from their anti-government views and embrace the new spirit of nationalism and suspicions of a deep-state conspiracy that had taken root in Washington. Mr. Rhodes was particularly vocal in supporting the former president’s relentless lies that the 2020 elections were marred by fraud and that President Biden’s victory was illegitimate.
One week after Election Day, Mr. Rhodes told the conspiracy theorist Alex Jones that he had men stationed outside Washington prepared to act at Mr. Trump’s command. And at a rally in the city on Dec. 12, he called on Mr. Trump to invoke the Insurrection Act, suggesting that a failure to do so would result in a “much more bloody war.”
Some of the Oath Keepers charged in connection with the Capitol attack have evinced a similar devotion to Mr. Trump. According to court papers, Ms. Watkins said she was “awaiting direction” from Mr. Trump about how to handle the results of the vote only after the election took place.
“POTUS has the right to activate units,” she wrote in a text message to an associate on Nov. 9, according to court documents. “If Trump asks me to come, I will.”