One of the U.S. Capitol police officers who defended the federal building and Congress members inside it during the Jan. 6 insurrection is running for office.

Harry Dunn announced his candidacy nearly three years to the day when he had to face violent rioters who stormed the Capitol building in Washington, D.C., in a deadly attack to stop Congress members from certifying then-President-elect Joe Biden’s electoral victory.

Dunn is running to represent Maryland’s 3rd District, which stretches between Baltimore and D.C., and replace Democrat Rep. John Sarbanes, who isn’t seeking re-election. Dunn doesn’t currently live in the district but said he would relocate there if he won.

“On January 6th, I defended our democracy from insurrectionists as a Capitol Police Officer. After, President Biden honored me with the Presidential Citizens Medal,” Dunn wrote in a statement announcing his bid for office. “Today, I’m running for Congress to stop Trump’s MAGA extremists & ensure it never happens again.”

Dunn started making a name for himself after he passionately testified before a House select committee investigating the insurrection about what he experienced firsthand that day. He told lawmakers he was berated and assaulted by rioters and called racial slurs. He’s appeared numerous times in court for the trials of numerous Jan. 6 rioters and even testified during the Oath Keepers’ seditious conspiracy trial in 2022.

He left the police force last year after 15 years on the job. He went on to publish a memoir in October calling for accountability and highlighting the trauma he underwent as a result of the riot.

Dunn is running as a Democrat for the congressional election and is up against five other Democrats currently serving in the Maryland General Assembly. He told POLITICO that he wasn’t intimidated by the crowded field, calling his opponents “career politicians” while saying he’s a “career public servant.”

“I truly believe that is one of the reasons why because I am no stranger to public service. I spent the last 15-plus years of my life dedicated not only to public service but to defending democracy,” Dunn told POLITICO.

He’ll reportedly be focusing on democracy protection, gun reform, mental health, infrastructure and transit, and public safety as part of his platform.