Joseph Biggs faces charges of obstructing Congressional proceedings, entering a restricted building, disrupting government business, disorderly conduct and more in connection with the chaos.
An FBI affidavit identified Biggs as the man shown in several photos in and around the Capitol Building.
Investigators said he admitted to being present inside the building but denied taking part in any forced entry and said he was not aware of any plans to storm the Capitol.
Biggs and other Proud Boys members, the affidavit alleges, were not dressed in the Proud Boys usual colors of yellow and black but wore “incognito” clothing. It was a move both Biggs Proud Boys leader Enrique Tarrio had called for in late December in a videos shared on social media, authorities said.
Photos purported to be of Biggs show a man in a blue and gray plaid shirt, blue jeans, a winter cap and glasses.
The affidavit alleges that Biggs was part of a crowd that rushed past Capitol Police officers at a metal gate outside the building and eventually breached the doors.
According to the affidavit, a video shared online shows another alleged Proud Boy, Dominic Pezzola, breaking a Capitol window a few moments before Biggs allegedly made it inside.
The FBI agent who wrote the affidavit, whose name was redacted, said he saw livestreamed video of the riot on Parler and used it to identify Biggs.
“In the video, a voice off camera says, ‘Hey Biggs, what do you gotta say?’” the affidavit reads. “The [man identified as Biggs] smiles broadly and replies, ‘this is awesome!’ before pulling his gaiter up to cover his face.”
Investigators also said they saw a number of Proud Boys using radios to communicate during the breach and included several pictures of men wearing earpieces as evidence.
Fox News Jake Gibson contributed to this report.