Harry Dunn, Capitol Police officer on Jan. 6, announces run for Congress

He's said he's fighting to hold Donald Trump accountable.

Harry Dunn, who struggled to defend the Capitol on Jan. 6, 2021, and has been one of the most outspoken members of law enforcement to condemn the attack, announced Friday that he is running for Congress.

Dunn, who resigned as a Capitol Police officer last month, said he is running as a Democrat to represent Maryland's 3rd Congressional District, which includes several Maryland counties outside Baltimore. He is running to replace Democrat Rep. John Sarbanes, who is not seeking reelection.

Dunn, who delivered memorable testimony before the House Jan. 6 committee, recalled the horrors of the day in an exclusive interview with ABC News Chief Justice Correspondent Pierre Thomas.