This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

DENVER (KDVR) — Robert Gieswein, 24, turned himself over to authorities in Teller County Monday evening, according to the Teller County Sheriff’s Office. Federal prosecutors are accusing Gieswein of participating in the insurrection at the U.S. Capitol on Jan. 6.

Investigators said Gieswein appears to be associated with a radical militia group known at The Three Percenters. The group has been in existence for more than a decade. The organization has been particularly active during the presidency of Donald Trump, according to the Anti-Defamation League (ADL).

Gieswein is accused of assaulting a police officer and obstructing a federal proceeding during the Capitol attack. On Sunday, FBI agents swarmed a Woodland Park property where the defendant previously lived. Agents have been zeroing in on his alleged affiliation with The Three Percenters.

“[The Three Percenters] have aligned themselves to be often a protector of President Trump,” said Scott Levin, a regional director of the Anti-Defamation League. “They have been– and are often seen– wearing military garb and carrying weapons.”

The militia members have shown up to anti-Trump protests where they’ve been accused of intimidating those who push back against the Trump agenda.

“These people believe that they need to stand up at this time, and mainly they [believe they] need to stand up against the government that they see as being tyrannical,” Levin said.

The group’s name has roots in the American Revolutionary War. It is inspired by the false allegation that only 3% of colonists resisted British rule during the birth of the United States. Over the past year, members have organized efforts against governors and public health officials concerning COVID-19 restrictions.

“These militia movements have made their way across the United States,” Levin explained.

Levin said the ADL supports free speech, but he is concerned about militia members’ ability to intimidate, incite violence and break laws.

The Teller County Sheriff’s Office reported on Monday evening that Gieswein had turned himself over to authorities at the Teller County Jail. Deputies said Gieswein will be handed over to federal authorities.