Leary spoke to CBS "This Morning" Co-Anchor Mark McEwen about the new role. "This is a story that was sitting in my head for a long time," he explains. "It's set in a working-class Irish neighborhood, where trust and loyalty are all that's important. That gets tested with drugs and guns."
Leary says he was able to help the other actors in the cast, because he knew so intimately the scene in which this film is set. "If I couldn't have played this guy, I should have gotten another job - become a priest or something."
You might know Leary from his other job. He became famous for his fast-talking, chain-smoking one-man comedy shows. But acting actually came first.
"I was plucked out of the hallway when skipping class, by a nun, and cast in a school play," he recalls. "I wasn't much of a student. I wasn't going to make it as a hockey player."
Now, he says, he counts his blessings. "I consider myself the luckiest man. I get to do stand-up, nothing beats that. I get to do this character, to play opposite Dustin Hoffman in Wag The Dog; I couldn't be happier."
Leary, whose family still lives in the Boston area, has three movies coming up in the next year. Look for him in A Bug's Life, playing a male ladybug.
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