It is the heaviest sentence handed down so far in the multiple proceedings opened following January 6.
A supporter of former US President Donald Trump was sentenced to five years in prison on Friday for assaulting police in the assault on Capitol Hill.
Robert Scott Palmer, 54, was seen wearing an American flag jacket and Florida for Trump cap, throwing boards, a fire extinguisher and other objects at police near the Capitol.
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The man then attempted to enter the iconic building of American democracy but was then repulsed by the pepper spray used by security - which did not prevent him from continuing his jets, until he was hit by a rubber ball.
Federal Judge Tanya Chutkan rejected his handwritten apology, in which he claims to have been duped by the former president, whom he describes as "tyrannical."
"I realized we had been lied to," he wrote, referring to supporters of President Trump.
"Sabotaging a democratic election and the peaceful transition of power"
But the prosecution pointed out that after these convictions recorded in October, Robert Scott Palmer had defended his action that day, while the description of an online pot launched to support him blamed the violence on the police. "Mr. Palmer knowingly joined a group of rioters with the specific intention of interfering in the national electoral process," the prosecution recalled in a document intended for the judges. "Mr. Palmer's violence was intended to further his political goal: to sabotage a democratic election and the peaceful transition of power," the prosecution added.
On January 6, thousands of supporters of Donald Trump rushed to Congress where they had entered by force to prevent the American elected officials from certifying the victory of Joe Biden in the presidential election.
So far, the heaviest sentence for these events had been 41 months in prison - just over three years - for two men convicted of obstructing process.
More than 700 people are being prosecuted as a result of the attack, most of them for minor offenses, such as unauthorized entry into the Capitol.
But several dozen are also targeted by heavier prosecutions, accused in particular of assault, use of lethal weapon and criminal conspiracy.