Jacob Chansley, known as "QAnon Shaman," is facing 51 months in prison for the January 6 Capitol riot.
Chansley is among hundreds of people arrested for the alleged involvement that took five lives.
He stormed into the U.S. Capitol shirtless, wearing face paint with the American flag colors and a hat with horns. QAnon Shaman pleaded guilty in September, and his sentencing is scheduled for November 17.
Prosecutors recommended a punishment of 51 months in prison, followed by three years of supervised release and $2,000 restitution.
His attorney, Albert Watkins, told NBC:
"The prosecutor's recommendation supports the proposition that the Government remains willfully delusional about their role in the events of January 6 of a young gentleman with zero criminal history and long-standing mental health vulnerabilities. It is shameful."
Chansley is among a few who became recognizable after the images of people who broke into the Capitol spread across the world as Congress met to verify the vote count of the Electoral College in the 2020 presidential election.
"Defendant Chansley's now-famous criminal acts have made him the public face of the Capitol riot."
They added he spread "false information and hateful rhetoric" on social media that encouraged rioters further.
Prosecutors added that Chansley was the first among 30 people who got inside the Capitol.
Once he was in the Gallery of the Senate, he shouted profanities and refused to get out:
"He proceeded to take pictures of himself on the dais and refused to vacate the seat when asked to do so by law enforcement."
He left a note:
"It's Only A Matter of Time."
"Justice Is Coming!"
Prosecutors further wrote:
"Armed with a six-foot-long spear, the defendant brazenly marched past dozens of law enforcement officers, with rioters throwing debris of all kind at those who opposed them, past broken windows and through doors ringing with alarm bells."
Chansley was arrested in Arizona on January 9. He pleaded guilty to a single federal charge of felony obstruction of an official proceeding. Prosecutors noted that Chansley showed no remorse.
So far, the Department of Justice has brought charges or indictments against 650 defendants for the Capitol riots. The sentencing memorandum said that at least 90 pleaded guilty to misdemeanor charges, and at least 15 have maintained guilty to felony charges.
Many of those arrested are QAnon conspiracy theorists who backed up Donald Trump's claims of election fraud and believe that the Democratic party promotes child sex trafficking, among other things.