“I thought Nan and I would hit it off,” Mazza told investigators as they prepared to finish their interview. “I was glad I didn’t because you’d be here for another reason and I told my kids that if they show up, I’m surrendering, nope they can have me, because I may go down a hero.”

Though reports of rioters charged with carrying firearms have been limited, the number has been steadily climbing. A former DEA agent brandished his service weapon outside the Capitol. A Texas man was charged with bringing a handgun as well. Leaders of the Oath Keepers charged with conspiring to prevent Congress from certifying the 2020 election aren’t facing firearms charges, but prosecutors have pieced together evidence suggesting they kept a stockpile of weapons at a hotel in nearby Arlington, Va.

The mounting evidence has undercut claims by former President Donald Trump and his allies that the mob attacking the Capitol was unarmed. In addition to the growing number of firearms authorities suspect were carried onto Capitol grounds, rioters brought knives, axes, batons, tasers, bats, poles and even a crutch and hockey stick. Others stole police shields and used metal barricades and furniture as makeshift weapons.

But Mazza’s case is the most clear-cut yet of a loaded firearm on Capitol grounds that day. Prosecutors obtained the gun from the alleged assailant himself and used its serial number to trace it back to him. They located Mazza after learning that on Jan. 8, Mazza himself reported the gun stolen to local authorities. He told the Shelbyville police that it was taken from his car on Jan. 5 while he was driving through Ohio. Mazza’s report was entered into a national database, which Capitol Police accessed as they attempted to find the gun’s owner.

Mazza is facing charges of obstructing Congress and the FBI investigation of the Jan. 6 attack, as well as carrying a firearm on Capitol grounds and obstructing police, as well as a D.C. code violation for bringing an unlicensed firearm into the city.

The Capitol Police sergeant who obtained Mazza’s gun at first struggled to identify him when shown pictures — instead identifying a younger-looking man with similar facial features. He admitted he was uncertain of his assailant’s identity in part because he was wearing a hat.

Although the charging documents describe repeated efforts by Mazza to help break the police line — from engaging in a collective push to overwhelm the officers to swinging a baton he obtained at officers — there’s also another odd twist in his case.

Investigators say that when two officers were pulled into the crowd of rioters from the tunnel — including D.C. police officer Michael Fanone — Mazza appeared to intervene and possibly seek to “thwart other rioters from attacking the officers.”