PASADENA, Calif. — When he was younger, actor Donnie Wahlberg often was on the wrong side of the law. Now he’s not only on the right side, he’s leading a cheering section for the boys in blue.

Wahlberg, one of nine kids from a blue-collar suburb of Boston, not only has played a policeman on two impressive TV series: “Boomtown” and CBS’ “Blue Bloods,” but he’s producing his own reality show about Beantown’s cops, “Boston’s Finest,” airing on TNT.

“It’s a big risk for any police department to do something like this, and I think, for them, they would only entrust it to a local boy,” he says in a noisy lounge of a hotel here.