An elected official from New Mexico went on trial on Monday with a judge, not a jury, set to decide if he is guilty of charges that he illegally entered the US Capitol grounds on the day a pro-Trump mob disrupted the certification of Joe Biden’s presidential election victory.

That’s not the only unusual feature of the case against Otero County Commissioner Couy Griffin, an Otero county commissioner, whose trial in Washington DC, is the second among the hundreds of people charged with federal crimes related to the January 6 riot.

Griffin is one of the few defendants not accused of entering the Capitol or engaging in violent or destructive behavior. He claims he has been prosecuted for his political views.

One of three members of the county commission in southern New Mexico, he is among a handful of defendants who either held public office or ran for a government post in the years before the attack.

He is among only three defendants who have asked for a bench trial, which means a judge will decide his case without a jury. A US district court judge, Trevor McFadden, was scheduled to hear one day of testimony.

Griffin, a 48-year-old former rodeo rider and pastor, helped found a political committee called Cowboys for Trump. He vowed to arrive at the courthouse on horseback. Instead, he showed up on Monday as a passenger in a pickup truck that had a horse trailer on the back.

Griffin is charged with two misdemeanors: entering and remaining in a restricted building or grounds and disorderly and disruptive conduct in a restricted building or grounds. His attorney, Nicholas Smith, said prosecutors apparently believe Griffin engaged in disorderly conduct by peacefully leading a prayer on the Capitol steps.

“That is offensive and wrong,” Smith told the judge in brief opening statements.

Prosecutors didn’t give any opening statements. Their first witness was Matthew Struck, who joined Griffin at the Capitol as his videographer. Struck has an immunity deal with prosecutors.

In a court filing, prosecutors called Griffin “an inflammatory provocateur and fabulist who engages in racist invective and propounds baseless conspiracy theories, including that communist China stole the 2020 presidential election”.

Griffin’s attorneys say hundreds if not thousands of other people did exactly what Griffin did on January 6 and have not been charged.

“The evidence will show that the government selected Griffin for prosecution based on the fact that he gave a speech and led a prayer at the Capitol, that is, selected him based on protected expression,” they wrote.

More than 770 people have been charged with federal crimes. More than 230 have pleaded guilty, mostly to misdemeanors, and at least 127 have been sentenced. About 100 others have trial dates.

Earlier this month, a jury convicted a Texas man, Guy Wesley Reffitt, of storming the Capitol with a holstered handgun in the first trial for a riot defendant. Jurors also convicted him of obstructing Congress, of interfering with police officers guarding the Capitol and of threatening his two children if they reported him to law enforcement.

Reffitt’s conviction could give prosecutors more leverage in negotiating plea deals or discourage other defendants from going to trial. The outcome of Griffin’s trial also could have a ripple effect, helping others decide whether to let a judge or a jury decide their case.

In a video taken in a parking lot outside the Capitol on 5 January, Griffin said he came to Washington for “possibly the most historic day for our country in my lifetime” and trusted that the vice-president, Mike Pence, would “do the right thing” and stop certification of Biden’s win.

After attending Donald Trump’s “Stop the Steal” rally, Griffin and Struck walked over barriers and up a staircase to enter a stage under construction on the Capitol’s Lower West Terrace for Biden’s inauguration, according to prosecutors.

Struck is listed as one of three government witnesses. Prosecutors also intend to call a Capitol police inspector and a US Secret Service inspector. Prosecutors want to use Griffin’s own words against him. They plan to play video recordings of his statements and actions in Washington.

After climbing over a stone wall and entering a restricted area, Griffin said: “This is our house. We should all be armed.” He called it “a great day for America” and added: “The people are showing that they have had enough,” prosecutors said.

A key question is whether he entered a restricted area while Pence was on Capitol grounds, a prerequisite for the US Secret Service to invoke access restrictions. Griffin’s attorneys say Pence had departed before Griffin could have entered a restricted area.

“The government responds that the vice-president’s precise location ultimately doesn’t matter,” the judge wrote on Friday. “Perhaps, although the lack of clarity about the metes and bounds of the restricted area and the vice-president’s movements on January 6 undermine this argument.”