A Maryland man who draped himself in a far right-affiliated flag and sprayed a fire extinguisher at police during the deadly Capitol attack on January 6 has been sentenced to nearly three years in prison, according to federal court records.

Matthew Ryan Miller, 23, pleaded guilty in February to felony obstruction of an official proceeding – that day’s joint congressional session to certify Joe Biden’s win over Donald Trump in the 2020 presidential election – as well as assaulting, resisting or impeding police officers.

At a hearing on Monday, Miller was sentenced to two years and nine months. Judge Randolph Moss also ordered Miller to spend two years on probation after his release and to pay $2,000 in restitution.

Federal prosecutors had asked the judge for a sentence of four years and three months. Seeking leniency for his client, Miller’s attorney, A Eduardo Balarezo, argued that the defendant was abusing alcohol and marijuana and therefore was not thinking logically on the day of the Capitol riots.

“Matthew is a young man who made a terrible decision,” Balarezo wrote in a court filing ahead of the sentencing. “He recognizes that his personal conduct and participation in the riot were not born of a rational decision but rather were fueled by alcohol and marijuana abuse.

“He fully accepts responsibility for what he has done and is not making excuses.”

Balarezo also condemned Trump’s claims that the 2020 presidential election was stolen from him by electoral fraudsters as “lies” that drove Miller to join other Trump supporters in the nation’s capital on the day the riots occurred because he thought “it would be cool to be part of history”.

According to prosecutors, Miller had traveled from his home in Cooksville, Maryland, and donned a black cowboy hat and a Washington Capitals jersey. He also tied around his neck the flag of Maryland and the Gadsden flag, which shows a hissing snake on a yellow background and is popular with far-right extremists.

A summary of the case endorsed by Miller said he used a metal barrier as a ladder to climb a Capitol wall before urging others to help him push against police, waving his hand and shouting, “Come on,” as well as “One, two, three, push!” while his companions yelled, “Heave! Ho!” and rhythmically pressed on towards a tunnel entrance being guarded by officers.

In the tunnel, Miller sprayed a fire extinguisher at officers, prosecutors wrote in records. Another mob member, Robert Palmer, picked up that extinguisher and sprayed it at officers, before tossing it at them. Palmer pleaded guilty to a role in the riot and got a prison sentence of five years and three months.

There was evidence Miller had been to at least one rally staged by the Proud Boys, a far-right group classified by the FBI as “extremist”, which had members at the forefront of the Capitol attack. Yet prosecutors did not provide any evidence or allege that Miller was working with the Proud Boys that day, though they noted that he did belong to an organization which named itself the Patriotic American Cowboys.

A bipartisan Senate report linked seven deaths to the Capitol attack. More than 840 people have been charged with federal crimes related to the January 6 riot, and nearly 300 of them have pleaded guilty, largely to misdemeanors. About 160 of them had been sentenced entering this month.