Klete Keller, a five-time U.S. Olympic medalist in swimming, pleaded guilty on Wednesday to a felony charge related to his role in storming the Capitol on Jan. 6 with the intention of stopping the certification of the Electoral College vote.

Keller was indicted on seven charges, but as part of a bargain with prosecutors he pleaded guilty in United States District Court in Washington to one felony count of obstructing an official proceeding before Congress. As part of the agreement, Keller promised to help law enforcement with any continuing investigation into the attack on the Capitol.

More than 600 people have been arrested in relation to the events of Jan. 6, but Keller was one of the most recognizable, because of his 6-foot-6 frame and the fact that he was wearing an Olympic team jacket with “USA” printed across the back.

According to his plea, Keller spent about an hour in the Capitol building on Jan. 6. He yelled expletives about Nancy Pelosi, the House speaker, and Chuck Schumer, the Senate majority leader; took photographs and video; and “jerked his elbow” to avoid law enforcement officers who were trying to remove him from the building, according to the plea. He later destroyed the phone and a memory card he had with him, according to the plea, and threw away the jacket that had made him so recognizable.

No date for a sentencing has been set. The charge carries a sentence of up to 20 years in prison, but the first Capitol rioter to plead guilty to the same charge was sentenced to eight months.

Keller, 39, was a freestyle swimmer who competed in the 2000, 2004 and 2008 Olympics. He won five medals overall and two golds in relay races, most memorably in Athens in 2004 when the U.S. men defeated the seemingly unbeatable Australians in the 4x200-meter freestyle relay.

But Keller struggled to transition to life beyond swimming, according to friends, family and former teammates who spoke with The New York Times. He and his wife divorced and fought for custody of their three children, and for nearly a year Keller lived out of his car. Throughout 2020 his social media accounts, since deleted, showed an increasingly intense focus on politics and a strong allegiance to former President Donald J. Trump. Last November, when he was working for a real estate company in Colorado Springs, he traveled to Washington for a pro-Trump rally called the Million MAGA March.

Two months later came the trip that led to Keller yelling in the Capitol rotunda with hundreds of others. He was arrested the next week, and has since been out of jail on a personal recognizance bond. Keller has said almost nothing publicly besides a few words in court, and Wednesday’s pleading was the most extensive account he has given about his actions on Jan. 6 and his reason for being in the Capitol.

Keller’s lawyer, Edward B. MacMahon Jr., did not immediately respond to a telephone message left on Wednesday.

Alan Feuer contributed reporting.