A prominent follower of the baseless conspiracy theory QAnon has been charged over the US Capitol riots.
Jacob Anthony Chansley, known as Jake Angeli, is in custody on charges including violent entry and disorderly conduct.
Mr Chansley, who calls himself the QAnon Shaman, is allegedly the man pictured with a painted face, fur hat and horns inside Congress on Wednesday.
Donald Trump faces another impeachment charge for his role in the unrest.
Democrats accuse the president of encouraging the riots, in which five people died.
The FBI has been appealing to the public to help bring the assailants to justice.
Mr Chansley has not commented publicly on the charges.
A statement from the federal attorney for Washington DC said: "It is alleged that Chansley was identified as the man seen in media coverage who entered the Capitol building dressed in horns, a bearskin headdress, red, white and blue face paint, shirtless, and tan pants.
"This individual carried a spear, approximately 6 feet in length, with an American flag tied just below the blade."
Truth and God on his side
By Sophie Long, BBC News, Phoenix, Arizona
I arranged to meet Jake Angeli, also known as the "Q Shaman", at a rally in Phoenix on Saturday to talk about his role in Wednesday's riot, or in what he called that "beautiful day".
Timings were difficult he said, because he had a voluntary appointment with the FBI first.
I didn't find that surprising. The fact he thought he might be free to leave, more so.
But he was unperturbed because, he said, he had done nothing wrong and he had truth and God on his side.
Earlier I asked Trump supporters in Tuscon if what they saw on Wednesday had changed their opinion of the outgoing president. No, they said, it was peaceful protest that had been infiltrated by violent members of the far left.
I asked Jake Angeli if that was what he witnessed. He told me there were no members of Antifa or any other left-wing organisations present in or around the Capitol building on 6 January. It was "patriots doing what our founding fathers would have done". The reason he knew that was "because Antifa are cowards who have no commitment to their country or their cause".
The statement said police had also detained a man from Florida believed to have been photographed carrying House Speaker Nancy Pelosi's lectern from the House of Representatives chamber.
Adam Johnson, 36, is being held on charges including one count of theft of government property and one count of violent entry.
Also among those charged is West Virginia state lawmaker, Derrick Evans. He is alleged to have posted a video of himself online, standing outside the building with Trump supporters, and then going inside.
He was arrested on Friday and is also accused of violent entry and disorderly conduct on Capitol Grounds, the Department of Justice statement said.
More than a dozen people have now been charged in offences related to the assault on the Capitol building. They include an Alabama man allegedly found with 11 Molotov cocktails near the unrest.
Mr Trump is due to leave office in 11 days. Democrats in the House of Representatives plan to introduce an article of impeachment against him on Monday, for "incitement of insurrection".
A White House spokesperson said impeaching the president at this late stage would only further divide the country.