The father of a U.S. Marine killed in the 2021 Kabul airport bombing was arrested for disrupting President Biden's State of the Union address on Thursday.

Why it matters: The disruption by Steve Nikoui as an invited guest of a member of Congress was an extremely rare break in decorum that punctuated a night filled with heckling from lawmakers.

The big picture: Nikoui is the father of Lance Cpl. Kareem Nikoui and was a guest of Rep. Brian Mast (R-Fla.).

• He yelled "Abbey Gate" and "United States Marines," a reference to the bombing in Afghanistan's capital, after Biden said "America is safer today than when I took office."

What they're saying: "Tonight at approximately 10:15 p.m., a man disrupted the State of the Union Address by yelling," a Capitol Police spokesperson told Axios.

• "Our officers warned him to stop and when he did not, the man was removed from the House Galleries and was arrested."

The other side: "The Sergeant at Arms is holding my State of the Union guest for yelling at [Biden] in protest because his son was killed in action at the Abbey Gate due to Biden's incompetence," Mast said in a post on X.

• "So much for the right to petition our government for the redress of grievances."
• House Foreign Affairs Committee Chair Michael McCaul (R-Texas), who held a roundtable with Nikoui last year, called the charges "petty."
• "The charges seem a little overbearing ... I'm a [former] federal prosecutor, I'm a rule-of-law kind of guy, but for me this was the most free speech exercise."

Zoom in: McCaul told reporters Nikoui informed him ahead of time that he planned to disrupt the speech, saying he "didn't encourage him to do it" but "it was his choice to make."

• "I said, 'Look, this is between you and your God and your conscience and your son and the other families' .... at the end of the day, I just said, 'have some courage for your son.'"

What's next: Nikoui was charged with a local misdemeanor charge of "crowding, obstructing or incommoding," the Capitol Police spokesperson said.

• D.C. code prohibits protesting "in an area where it is otherwise unlawful to demonstrate" and continuing "after being instructed by a law enforcement officer to cease."
• The charge carries a fine of up to $500 and 90 days in prison.

Editor's note: This story has been updated with additional details.