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PORTLAND, Ore. — A former Marine whose appearances in widely shared videos made him one of the most recognizable figures during the armed takeover of an Oregon wildlife refuge pleaded guilty Monday for his role in the weekslong standoff with authorities.

Jon Ritzheimer, 32, admitted that he conspired with Ammon Bundy and others to prevent U.S. Interior Department employees from doing their jobs at the Malheur National Wildlife Refuge, and they did so by threats of force or intimidation.

This Jan. 27, 2016, file photo provided by the Maricopa County Sheriff's Office shows Jon Ritzheimer, who was arrested in Arizona Jan. 26, 2016, in connection with the occupation of the Malheur National Wildlife Refuge in Oregon. AP

Prosecutors dropped two charges as part of a plea agreement — theft of government property and possessing a firearm on federal property. Assistant U.S. Attorney Craig Gabriel said prosecutors will recommend 2½ years in prison when the Arizona man is sentenced in May. Ritzheimer's attorney, Terri Wood, can argue for less.

Ritzheimer arrived in Oregon shortly before the Jan. 2 takeover. The group sought local control of Western lands and opposed the prison sentences two local ranchers received for setting fires.

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In a video posted Dec. 31, Ritzheimer sits in the driver's seat of his truck and emotionally explains to his daughters why he missed Christmas and won't be home for New Year's.

"Your daddy swore an oath," Ritzheimer said. "He swore an oath to protect and defend the Constitution."

The YouTube video spawned parodies and the hashtag #DaddySworeAnOath. It has been viewed more than 600,000 times.

Later, in a video released during the occupation, he reacts angrily when opponents respond to a call for supplies by sending sex toys to the refuge. "Rather than going out and doing good, they just spend all their money on hate and hate and hate and hate," he said, before knocking the mail from a table to the floor.

The takeover occurred on the same day as a rally for the two ranchers, Dwight and Steven Hammond.

Ritzheimer was part of the initial convoy that arrived at the refuge near Burns, Oregon, and took control, authorities say. They informed Bundy, who was at the rally, that they had seized the place.

Occupier Jon Ritzheimer help supporters Joe Rigney, left, and his wife Amanda Rigney unload firewood at the refuge on Jan. 10. JIM URQUHART / Reuters

Ritzheimer used his own truck to block an entrance during the occupation and organized armed guard duties, said Gabriel, the prosecutor. Authorities seized a shotgun that he brought to the refuge.

Ritzheimer told U.S. District Court Judge Anna J. Brown that he helped "take the protest to the next level."

After the hearing, Ritzheimer said he pleaded guilty because he reviewed the charge and, though he may not agree with it, admits he violated the law as it's written. "Marines believe in integrity," he said.

Ritzheimer made news outside of Oregon last year by organizing an anti-Islam protest at a Phoenix mosque and threatening to arrest a U.S. senator for treason because she supported the Iran nuclear deal.

He also led a protest at Walmart after the company removed Confederate flag merchandise.