“Law & Order” star Jesse L. Martin won’t leave his signature role as Detective Ed Green until he’s interrogated a guy from Lewiston.

Actor Lou Carbonneau, 36, a Lewiston native and a 1994 Bates College graduate, has a small role in Wednesday night’s episode as an autistic bookie who gets beaten up.

Then, he gets questioned by Green and his partner, Cyrus Lupo, played by Jeremy Sisto.

He has two scenes. Likely screen time: two or three minutes.

“It’s very cool,” Carbonneau said.

The TV stars were easy to act with and the episode, which is being promoted by NBC as “a very special Law & Order,” ought to get a large audience for its 10 p.m. showing.

Carbonneau only discovered that the episode was a big deal after he’d been cast and read the script. Martin, who has been on the long-running series for eight years, was written out.

The two had also worked together before.

Several years earlier, Carbonneau was cast on both “Law & Order” and its sister show, “Law & Order: Special Victims Unit” as a crime scene technician. He did 13 episodes in all.

“I had lines like, ‘Hey guys, I found the underwear,'” he said.

The work helped pay the bills in New York City, where the shows are filmed. He also joined a huge pool of theater actors whose resumes include work on the show.

“If you’re a New York actor and you haven’t done ‘Law & Order,’ there’s a problem,” he said.

Besides, the company is good.

“They were just the coolest people I ever worked with,” Carbonneau said.

And though he’s had few high-profile parts, the shared-a-scene ranks are improving. Only a week ago, he had a few lines with an idol: Robert DeNiro.

The screen legend is shooting the drama “Everybody Wins” in Connecticut. Carbonneau had a bit part as a grill salesman.

“I prepared for that as much as I have prepared for anything,” he said. They did eight takes. Before they were done, the pair had improved together. The man who played Jake La Motta and Don Vito Corleone had begun making up lines before the camera rolled.

“As an actor, he’s certainly not a diva,” Carbonneau said. “He’s there to work.”

The Lewiston native has also finished filming a low budget vampire movie, titled “Rosencrantz and Guildenstern are Undead.” The cast includes Sisto and Ralph Macchio.

It’s all exciting to Carbonneau, who remains a little tentative about promoting his growing career back home.

Of course, his parents, Lauretta and H. Paul Carbonneau of Lewiston, are proud.

Lauretta said Lou, her youngest child, played tennis, soccer and acted while at Lewiston High School, graduating as president of the Class in 1990.

“I’ll be home for Mother’s Day,” Carbonneau said.