TV

Sarah Shahi plays rough on ‘Person of Interest’

Sarah Shahi made an indelible impression when she did a guest spot last season on CBS’s “Person of Interest.” As government assassin Samantha Shaw, she knocked off half a dozen men and left Reese (Jim Caviezel) and Finch (Michael Emerson) stranded in a cemetery, making a getaway in an ambulance.

Cold-blooded. Merciless. Ruthless.

Now that Shahi, 33, has been hired as a series regular, these comparisons, it turns out, are the highest compliments you could pay her.

“Beating up on boys and killing them is pretty fun,” says the actress.

Shahi is standing outside Silvercup Studios on a sunny sidewalk in Long Island City, Queens, talking about how she found her way to the hit series, moving east from California. She’s also taking a breather from the smoke-filled studio where she has been doing a rescue scene in which Sam, as her character is called, comes to the aid of a young Russian immigrant girl hiding from people who want to abduct her.

Sarah shines at the “Bullet to the Head” premiere in NYC.Dimitrios Kambouris/WireImage

For the scene, Shahi and guest actor Danielle Kotch, who plays the immigrant, Genrika Zhirova, have gone in and out of a makeshift tunnel that has little headroom. At one point, Shahi falls. Multiply that one fall by 12 and you’ll come close to the number of takes she did. Shahi does not use a stunt double and wears minimal padding on her hips and knees.

“That’s part of the fun of all this, to do your stunts,” Shahi says. “I love heights. I love guns. I love shooting guns.”

Pardon, but did this pint-sized Texan say “guns”?

“Yeah, I just have a little 9 mil. I’m a girl in boy’s clothing,” she says. “I like to get a little rough. I prefer mud to makeup. That’s me in a nutshell.”

Shahi’s rise from featured player on the Showtime lesbian drama “The L Word” has been adroitly managed, with one NBC series, “Life,” costarring Damian Lewis (“Homeland”), and the short-lived USA series “Fairly Legal” already behind her. The success of the CBS series was a huge draw, even if it meant spending time away from her husband, Steve Mowey, a co-star on “Shameless,” which films in LA.

“Before that, whether it was ‘Life,’ or ‘The L Word’ or ‘Fairly Legal,’ even though those were all critical hits, I didn’t have the numbers behind those shows the way this show does,” she says.

Known for its extensive location shooting, “Person of Interest” put Shahi outdoors in her first week on the job.

“My first scene was on a rooftop in January. Coldest day of the year and I thought, ‘Why did I say yes to this job?’ ”

Shahi, who lives in Williamsburg, Brooklyn, has her 4-year-old son, William, to keep her company.

“I started traveling with him when he was about 2 weeks old. He’s been all over the world with me,” she says. “He’s been to Budapest. He’s been to London. He’s been to Monte Carlo. At the end of the day, the most important mark I will leave on this world is my son.”

Would Shahi, then, let her son experience the discomforts of the tunnel scene she’s been shooting with Kotch?

“F – – k no!” is her blunt, startling reply.

Our sidewalk conversation is interrupted by a production assistant, who summons Shahi back to the smoky depths of the studio. Inside, the director, Ken Fink, asks the crew to let the smoke clear so that Shahi and Kotch can do their blocking.

“I was hesitant to put a child in a smoky situation,” he says. “But there’s a 40-foot opening in the center, so it’s possible to get her in and out of there quickly. I wanted to see that she was scared. I wanted that sense of claustrophobia.”

What he also wanted was an actor ready for the physical challenges of the role. “Nothing is more fun for the director than an actor who’s going to the next level of responsibility,” he says. “There isn’t anything [Sarah] wouldn’t do.”

Not all the emphasis is on action. In her interaction with the Russian girl, Sam gives viewers a harrowing glimpse into her own childhood.

“We see Sam go from a person without an emotional life at all to someone who is jealous of those who have one,” Fink says. “And then we see someone who has one herself, but it’s on low.”

When the smoke has cleared, a chocolate cake is brought out for one of the crew and everyone sings “Happy Birthday.” Shahi, who plans to go home for Thanksgiving, fantasizes about having her husband as a guest star on the show one day.

“This show is so up his alley. He’s definitely envious,” she says. A tomboy to the end, she adds, “If he does do a guest spot, my only request is that I get to kill him.”