Harry Dunn, one of the many Capitol Police officers who defended the building during the Jan. 6, 2021, attack and who later told his harrowing story of violence and racism he experienced that day, announced he is running for Congress.

Dunn will run as a Democrat for the seat in Maryland’s 3rd District, which is currently held by Rep. John Sarbanes, a Democrat who said he would not seek reelection after nine terms.

“On January 6th, 2021, I did my duty as a police officer and as an American and defended our nation’s Capitol from violent insurrectionists,” Dunn said in a news release. “Today, I’m running for Congress because the forces that spurred that violent attack are still at work and as a patriotic American, it is my duty to defend our democracy.”

The race for the 3rd District, which includes the Baltimore suburbs in Howard and Anne Arundel counties, is rated Solid Democratic by Inside Elections with Nathan L. Gonzales. Joe Biden defeated Donald Trump for the White House in the district by 26 percentage points in 2020, and Sarbanes won his current term by 21 points in 2022.

There are already several Democrats contending in the open primary, according to the Maryland State Board of Elections.

Dunn was one of four officers who provided first-hand accounts of the insurrection to lawmakers and the nation at the inaugural hearing of the House select committee to investigate the Jan. 6 attack.

Around 140 law enforcement officers were assaulted that day — approximately 80 from the Capitol Police and 60 from Washington’s Metropolitan Police Department, according to the Justice Department.

Dunn described the brutal fighting where officers were injured by rioters using flagpoles, chemical irritants and projectiles. And he detailed the violence he encountered on the day of the Capitol attack and the vicious racism he endured in the form of racial slurs lobbed at him from pro-Trump rioters — some of whom were carrying Make America Great Again and Confederate flags — when he told them he voted for President Joe Biden.

At that July 2021 hearing, Dunn said the trauma he faced during the insurrection induced him to go to therapy and participate in peer support groups.

Biden awarded Dunn the Presidential Citizens Medal on Jan. 6, 2023.

He also was part of a push to convince enough Republican senators to vote in favor of establishing a 9/11-style commission to investigate the Capitol attack. Ultimately, GOP opposition in the Senate killed that effort. The House instead created the Jan. 6 select committee to investigate the insurrection.

Last fall, Dunn released a book on his experience on Jan. 6, 2021, the aftermath and his push for accountability.

He has been a Capitol Police officer since 2008 and served on the First Responder Unit where he would regularly stand guard in front of the Capitol. He resigned from the department on Dec. 18.

Dunn grew up in Prince George’s County, Md., and graduated from James Madison University in 2005 with a degree in health science. He played offensive line for the Dukes football team and was a part of the squad that won a national championship in 2004 (FCS, formerly Division I-AA). He has a daughter, Daphne.

Herb Jackson contributed to this report.