Every time I arrest somebody,” says Jason Wiles, who plays Maurice “Bosco” Boscorelli on NBC’s Third Watch, “I damage myself somewhere.” Tackling Nick Turturro last month, he tore one of his pecs to the point where he couldn’t breathe. But Wiles, 33, is getting used to the pain: This Friday marks the 100th episode of the hourlong drama about New York paramedics, cops, and firemen working the 3-to-11 p.m. shift. Wiles, who previously played Colin Robbins, the East Coast cokehead on 90210, never thought he’d get to play Bosco—who was initially written as six feet four and 250 pounds. “I’m five nine and 160,” he says, “so at my audition I went with the Napoleon syndrome—little guy who’s angry. I just about strangled John Wells, the creator! I was like, he either needs to think I’m going to kiss him or strangle him.” And when he’s not playing a cop, Wiles can often be found hanging out with them at Walker’s, his neighborhood bar in Tribeca. “When I first started the show, I was known as the ‘cop nerd.’ I was in the 9th Precinct in the East Village every day. I’d be at work wearing a fake bulletproof vest with foam in it, then I’d leave and put on a real one to ride around with these guys.”