Anthony Mackie as Coleman Harris on the Los Angeles set of "Gangster Squad" (Oct. 3, 2011). The crime thriller is set in the 1940s and based on a true story.

*With his robot boxing drama “Real Steel” topping the weekend box office with an $8.6 million debut, co-star Anthony Mackie is already knee deep into his next project “Gangster Squad,” an account of the LAPD’s real life fight to keep East Coast Mafia types out of Los Angeles in the 1940s and 50s.

Sean Penn stars as real-life mobster Mickey Cohen. According to the studio, he “runs the show” in LA, “reaping the ill-gotten gains from the drugs, the guns, the prostitutes and—if he has his way—every wire bet placed west of Chicago. And he does it all with the protection of not only his own paid goons, but also the police and the politicians who are under his control.”

Josh Brolin and Ryan Gosling play LAPD’s Sgts. John O’Mara and Jerry Wooters, the cops who try to shut Mickey down.

And Mackie’s character? “I’m the black guy in ‘Gangster Squad,’” he told EUR, referring to his role as Coleman Harris, a switchblade-toting cop who proudly patrols one of the most crime-ridden areas of the city.

(L-R) Ryan Gosling, Josh Brolin, Anthony Mackie, Michael Pena and Giovanni Ribisi between takes on the set of "Gangster Squad" in Los Angeles. (Oct. 3, 2011)

“I love the 1940s/1950s of American history,” he said. “Guys wore great hats and suits, women were like size 10s, you have amazing cars, like that was the beginning of the American muscle period, it was just an amazing time in this country. And I feel like the gangsters coming along at that time – like Mickey Cohen, like Al Capone, they seemed like fascinating fictional characters – fictional, because, who would take over a city? Really? Like if you tried to do that today…really?”

In the audio below, the New Orleans native says he had some studying to do about the City of Angels to absorb the mindset of an LAPD officer in the 40s and 50s – not to mention, and African American cop during the pre-civil rights era.

Anthony Mackie talks Gangster Squad by CherieNic