A defence lawyer told jurors the case against Guy Wesley Reffitt is based on "a lot of hype" and a "rush to judgment" against a man who is prone to bragging, exaggerating and ranting.
"He uses a lot of hyperbole, and that upsets people," Reffitt's attorney, William Welch, said.
But prosecutors said Reffitt drove from Texas to Washington, armed with guns, because he intended to storm the Capitol on January 6, 2021 and try to stop Congress from certifying President Joe Biden's electoral victory.
Assistant US Attorney Jeffrey Nestler said Reffitt's own words and actions, captured on video, show how he played a leadership role in a mob's attack against officers on the west side of the Capitol.
"The defendant was the tip of this mob's spear," Nestler said.
The verdict in Reffitt's trial could have an enormous impact on hundreds of other riot cases.
A conviction would give prosecutors more leverage to cut plea deals with others facing the most serious charges. An acquittal could embolden other riot defendants to seek more favourable plea terms or gamble on trials of their own.
Reffitt is charged with bringing a gun onto Capitol grounds, interfering with police officers guarding the building and threatening his teenage children if they reported him to authorities.
Reffitt was armed with a holstered handgun, carrying zip-tie handcuffs and wearing body armour and a helmet adorned with a video camera when he and other rioters charged at police officers while Vice President Mike Pence was presiding over the Senate, according to prosecutors.
Before they advanced, Reffitt used a megaphone to shout at police to stand down and step aside and urged the mob to push forward and overtake officers, Nestler said.
"In the defendant's own words, he lit the match that started the fire," the prosecutor told jurors.
Nestler said Reffitt brought the police-style cuffs with him so that he could restrain any members of Congress that he encountered. But he wasn't one of the hundreds of rioters who entered the building.
While the mob overwhelmed police and began pouring into the Capitol, Reffitt retreated after an officer pepper-sprayed him in the face, the prosecutor said.
Reffitt is a member of the 'Texas Three Percenters' and bragged about his involvement in the riot to other members of the militia-style group, according to prosecutors.
The Three Percenters militia movement refers to the myth that only three per cent of American colonists fought against the British in the Revolutionary War.
Prosecutors say photos and video of Reffitt during the riot show what appears to be a silver object in a handgun holster on his right hip. Welch has said no videos or photos show a gun in Reffitt's possession at the Capitol.
Welch also said there is no evidence that Reffitt damaged property, used force or physically harmed anybody.
"He never tried to assault anyone. He didn't help anybody else commit an assault," Welch said during opening statements that were significantly shorter than the prosecutor's 30-minute presentation.
More than 750 people have been charged with federal crimes related to the riot. More than 220 have pleaded guilty, more than 100 have been sentenced and at least 90 others have trial dates.
