Based on Tracy Letts' stage play of the same name, "Killer Joe" has McConaughey in the title role of a cop who moonlights as contract killer in the crime thriller directed by "The Exorcist" maker William Friedkin.

A drug dealer named Chris (Emile Hirsch) hires Killer Joe to murder his mother. When Chris can't pay the hitman an upfront fee, Killer Joe decides to take Chris' sister Dottie (Juno Temple) as collateral.

McConaughey, 42, recently played a defense attorney in "The Lincoln Lawyer" and a district attorney trying to put away a murderer in "Bernie." Last month, he bared almost all as the slick owner of an all-male strip club in "Magic Mike." The star sat down with Reuters to talk about "Killer Joe," his career choices and being a newlywed.

Q: What drew you to a low-budget, independent film that was dark and twisted, yet also comedic?

A: "It was real good character work for me. A real challenge and exercise in introversion. Because this character is very, very introverted. In 'Magic Mike,' (his character) Dallas (his character) is all extroversion, all showman. Killer Joe lives in the shadows, picking out times when he shows you some light."

Q: He is a ruthless killer, but has a soft spot for Dottie. He makes the audience gasp in horror and laugh nervously.

A: "He's a guy who needs family at the bottom of it all. That's what he's looking for. It's wonderfully twisted, cheerfully amoral, provocative and it's upsetting your stomach, but you're laughing at the same time. And you're questioning yourself: 'Wait a minute, which emotion should I be feeling? Is it okay to laugh?'"

Q: Did you choose to play him sinister or with humor?

A: "I never chose to play sinister, just play him clear. Half the time he whispers. He speaks his words very clearly. He's not in a rush. Every move is very deliberate. If a character is doing that, those characters can become a little scary where you're like, 'Man, if this guy got off balance, this could be trouble.'"

Q: You already have one hit playing, "Magic Mike," which has $102 million at box offices. Were you surprised at its success?

A: "It's done better than any of us thought it would do. But just talking about the basic DNA (of the film): male strippers. You want to see some male skin? That could hit a nerve. That could be something that a lot of people want to go see. And fortunately it has been. At its very basic, just look at the poster, and you go: male strip club, no one's ever made that before. So we knew that we had something that was original."

Q: You spent the better part of a decade doing romantic comedies with Kate Hudson, Sarah Jessica Parker, Jennifer Garner and Jennifer Lopez. Has it been a conscious decision to take a break from that genre?

A: "It's been conscious. I've been seeing some romantic comedies and some action adventure film stories that I just felt like I'd either 1) done a version of them before or 2) felt like I could do them tomorrow. And you know what? Nothing wrong doing something you feel like you can do tomorrow. But let me do something I'm not comfortable with, that quick. Let me do something I'm really excited about getting on the other side of the mystery with, but I don't know the answer (to)."

Q: So you like not knowing the answers to some of these characters...

A: "And I know I'm going to have to go to work and I'm going to have days where I'm going, 'I don't know who this guy is! What am I going to do?' And I'll figure it out. That's been a really fun process for me with all these (recent) characters. They are all very singular-willed characters, ones that are not pandering to anyone else is society. They make up their own rules ... and that's been really fun to hang my hat on."

Q: You recently married your longtime girlfriend, Camila Alvez, who is the mother of your son Levi, 4 and daughter Vida, 2. Do you feel different now that you've gone through a formal wedding ceremony?

A: "The ritual of what we did and what we're saying together with God in our lives and with our children means more. It feels like one whole thing."

(Editing By Zorianna Kit and Stacey Joyce)

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