Harry Dunn, a former Capitol Police officer who is among dozens running for Maryland’s 3rd Congressional District, is up on air with the first TV ad in the race. In the 30-second ad, Dunn speaks about his background and motivation to run over images of him walking to the U.S. Capitol Building in Washington, D.C. “For 15 years, I protected the promise that every one of us, no matter who we are, has a voice in our government,” Dunn says in the ad.