Alex O'Loughlin: Catching up with the 'Moonlight' star on his 'Criminal Minds' guest spot and more!

We know. You’re not used to seeing Moonlight‘s Alex O’Loughlin looking like a serial killer with OCD. (You prefer to remember him the way we do: either holding a "Hi Slezak!" sign at 2008′s New York Comic Con or shirtless.) But it’s only for a role. O’Loughlin guest stars on tonight’s episode of Criminal Minds (CBS, 9 p.m. ET) as what fans of the series know as the Unsub, or unidentified subject. He plays a man who sends a video of one of his murders to the BAU team, hoping that they’ll be able to end the bloody spree that he himself cannot stop. We phoned O’Loughlin for a quick chat about the part, his CBS drama pilot Three Rivers, and the romantic comedy he begins shooting next month with Jennifer Lopez, The Back-Up Plan.

ENTERTAINMENT WEEKLY: We can’t actually go further into your character on Criminal Minds without giving the twist away, but tell us how the part came to you.
ALEX O’LOUGHLIN: The genius writer and friend of mine Simon Mirren [one of the show's co-executive producers] offered it to me. I’m eating an apple while we talk. Is that okay?

That is fine, yes.
Thank you. I read it and was like, "Absolutely." It’s not often that I get to play character roles. You kinda leave drama school and you head off into a direction and that’s the direction you take. You’re either on the character actor route or the leading man route. It was a delight for me to play a role like this.

You are the leading man in the CBS pilot Three Rivers. [We'll know May 20, when CBS announces its fall schedule, if it gets picked up for next season.]
I play a cardiothoracic surgeon called Andy Yablonski, who’s based on a real-life surgeon called "Gonzo" Gonzales-Stawinski who’s become a wonderful friend of mine. He’s a cardiothoracic surgeon up at the Cleveland Heart Clinic, which I spent a bunch of time at in my preparation for the role. It’s a fantastic script that’s really grownup and smart and important. It tells the story of organ transplants from three perspectives: The organ, the recipient, and — the organ? [Laughs] It tells it from the organ’s perspective. From the recipient, the donor, and the surgical team.

I read that Andy is separated from his wife and lives in a motel near the hospital. Is that right?
Yeah, connected next to the hospital, actually. So he can live his job even more than he usually does.

The word motel always sounds kinda seedy to me, so I thought maybe we’d get to see him taking advantage of that proximity. But if he’s a workaholic…. Are we not gonna see sex scenes is basically what I’m asking you.
Ohmygod. No, I told them I’m happy to do whatever sex scenes they want. Either with actors or by myself. So they’re getting back to me on that. That may or may not be a reason why they pick up the show. "He’s obsessed with sex. No, we’re not gonna pick the show up. Moonlight f—ed with him. He’s kinda all weird now."

You have a holding deal with CBS, so I’m assuming you had a few pilots to choose from. Why this one?
It’s a well-written piece that I foresee a longevity with that I didn’t with the other pilots that I read. I see three years ahead, you know what I mean? I see the fifth season. I see where the characters are going to go, the potential. I loved the character. I’ve sat in on five open-heart surgeries now. I realized how important a story like this was before I did that stuff, but the deeper I’ve gone into it, the more mesmerized I am.

And what’s Andy’s personality like?
He’s a bit cheeky, too. He’s like a lovable scallywag.

You’re about to start filming the movie The Back-Up Plan with Jennifer Lopez. Tell us about that one.
It’s a movie about a girl who is heading toward her 40th birthday, she hasn’t met The One, she really wants a baby, and so she goes and gets artificially inseminated. Right after she does this, she bumps into this guy called Stan. I play Stan. She falls in love with him. He falls in love with her. She tells him about the pregnancy after they’ve fallen in love and he flips out. Then it’s about him coming to terms with the fact that if he loves her, he loves all of her, and working out how he’s gonna deal with it. It’s very funny. It’s very moving. It’s a terrific little film.

You’ve met Jennifer already, obviously. How’s the chemistry?
The chemistry is fine. I think we’re gonna be pals. You know when you sit in a room with someone and you kinda can’t talk to them, or you sit in a room and you’re easy with someone — we’re easy together. So I think it’s gonna work. I think we’re gonna be really good onscreen together. Her husband is wonderful. I met Marc and the kids, and they’re great. They’re a really lovely unit.

You also costar in the thriller Whiteout coming out this fall. [Kate Beckinsale plays a U.S. Marshal in Antarctica in the graphic novel adaptation.]
I can’t remember how many years ago I shot that. I can’t remember what I did in it. [Laughs] No, that’s not true. I’m looking forward to seeing that. They’ve been cutting it for so long. That’s Kate’s film though. Essentially, I play the villain in that as well. A rogue-ish, rugged, Australian pilot who’s a bit of a smartass. It’s like Wow, what a stretch.