When Michael Peña was approached about being in the film “Gangster Squad,” the actor did not have to mull it over.

The request had come, after all, from his friend and director Ruben Fleisher.

Having worked with Fleisher in “30 Minutes or Less,” and recalling the experience as “a great time,” the 36-year-old actor immediately agreed.

And Peña, known for his roles in “Crash,” “Battle: Los Angeles” and “Observe and Report,” was excited to work in what the industry calls an “ensemble” movie – a flick with a star-studded line-up.

In an ensemble movie, the principal actors and performers are assigned roughly equal amounts of importance in their roles and screen time.

“I love ensemble pieces,” he said in an interview Wednesday, adding, “It was one of the better times I’ve had doing a movie.”  

“Gangster Squad,” which opened in theaters Friday, chronicles the Los Angeles Police Department’s struggles against the spread of the East Coast and Chicago Mafia and gangs to California in the 1940s and 1950s.

The movie features Sean Penn as mob king Mickey Cohen, and Peña as Detective Navidad Ramirez, who he described as “the guy that goes up and tries to take down Mickey.”

The film was supposed to hit theaters last September. But the opening had to be delayed and scenes re-shot after the massacre at the midnight screening of “The Dark Knight Rises” in July inside a theater in Aurora, Colo.  There was no question for those in charge of the film that the movie, which originally included a scene in which there was a shootout inside of the famous Grauman’s Chinese Theater, had to be modified.

Peña said the overhaul of scenes and delay did not negatively affect the film, despite the entire cast having to be called in to reshoot the scene at a different location.

“I was actually pretty stoked about it, just as a person,” Peña said. “For Warner Brothers, they didn’t want to be insensitive, they had to toss in a good chunk of change to switch it up, and I thought that that’s commendable.”

The movie is based on the book "Gangster Squad," by former journalist Paul Lieberman, who described a time when gangs and mobsters like Mickey Cohen controlled police and politicians.

Besides Peña and Penn, the ensemble cast boasts Josh Broslin, Ryan Gosling, Nick Nolte, Emma Stone, Anthony Mackie, Robert Patrick, and Giovanni Ribisi.

In comparison to “End of Watch,” and the upcoming film “Chavez” in which Peña stars as the late civil rights leader Cesar Chávez, he described “Gangster Squad” as a welcomed change.

Peña enjoys the versatility of working in movies as opposed to being tied to a television series because of the ability to constantly play different roles.

“I love switching it up, I think that’s what you’re afforded when you do movies,” he said.

Peña was familiar with some of the cast, having previously worked with Gosling and Ribisi, calling them “awesome,” and twice with Mackie, who he described as “literally one of the funniest guys on the planet.”

Apparently, Mackie wasn’t the only funny guy on set.  According to Peña, Brolin provided some entertainment of his own with his famous impressions of people, adding that he probably“has done some of me too."

Working with seasoned actors is a blessing in Peña’s eyes. 

“I learn a lot from the veterans,” he noted.

The son of Mexican immigrants who settled in Chicago, Peña acknowledges that opportunities for Latinos like him in Hollywood have come a long way.

“It’s definitely different,” he said. “Ten years ago I didn’t have as easy of a time, not that it’s easy [now], but it was much harder 10 or 12 years ago.”

Peña went on to say that we are in the midst of a generational change when it comes to Latinos in Hollywood.

“Javier Bardem came on the scene, Gael Garcia and Diego Luna came out. That stuff just helps, raises awareness.”

When asked what advice he would give to an aspiring Latino actor, he said, “The same thing I would give anybody. A lot of times I would complain when I had to go out for what I considered to be a stereotypical role.”

But then he realized that typecasting didn’t just happen to Latinos.

“My roommates would get pegged for the same thing.  If you’re a really beautiful girl, you get those roles all the time. You can’t let the initial shock of Hollywood destroy your dreams. You’ve got to know that it’s part of the game.”

And so, he said: “I decided to play every character as a three-dimensional character instead of taking the easy road.”

For the future, Peña is interested in bio films, explaining: “I’m in a place right now where after ‘Chávez’ I would like to do more bio pics, for some reason I just love doing those. I want to do films, I don’t want to have it be a boring bio pic.”

He hopes to portray more famous figures in Latin American history, saying: “Cesar Chávez was a big dream of mine,” and adding that others he would like to portray include “Gigi Marquez, Diego Rivera, artists all over Latin America.”

“There are so many Latin Americans that haven’t been portrayed that I feel like I’m blessed that I’m in a position to be able to do that.”

E.J. Aguado Jr. is a freelance journalist living in New Jersey. Follow him on Twitter at: @ejaguado