Let's bust any of those preconceptions right now -- the R-rated dark comedy "Observe and Report" is far from a rehash of the recent squeaky-clean hit "Paul Blart: Mall Cop." Sure, the mall setting is familiar, but Seth Rogen's security guard character is, as co-star Ray Liotta puts it, "a mall cop with some problems."

In fact, writer-director Jody Hill has described Rogen's character as more of a Travis Bickle from "Taxi Driver," which predates "Paul Blart" by more than 30 years.

"I think Jody was influenced by the films of the 1970s and the concept of the anti-hero and that's what he was definitely going for here," Liotta said in a recent @ The Movies interview. "What makes this business great is that there are a lot of different people with different sensibilities -- Jody definitely likes to go for the extreme and I respect him for that."

Opening in theaters Friday, "Observe and Report" stars Rogen as Ronnie Barnhardt, a committed security guard whose duty to protect and serve is put to the test when a flasher wreaks havoc at the mall. Using the crime as an opportunity to prove his worth as police officer candidate and a hero to his elusive dream girl, Brandi (Anna Faris), Ronnie and his delusions of grandeur are interrupted by an equally competitive Detective Harrison (Liotta) -- a suave, local police officer who comes aboard to solve the case.

Liotta said that he admires the edgy projects Rogen takes on, which range from "Knocked Up" to "Zack and Miri Make a Porno," because it tends to defy Hollywood convention -- -- "Observe and Report" is no different.

"He's smart and working with good filmmakers. He's part of the whole Judd Apatow crew and he writes good stuff himself," Liotta said. "I think he has a strong sense of what he wants to do and who he wants to be in this business."

One thing that Rogen tends to do on his movies is improvisation, which of course, gives his fellow stars a chance to play along. But for the sake of his character, Liotta felt it was better to stick to the script for his scenes.

"On this film I play the straight man, so there was little room for me to go off on something yet stay consistent with who the character was," Liotta explained. "The more they would improvise, the more I would want to walk away and tell them, 'Shut up and get out of my face.' I was playing somebody who didn't want to be bothered with these people in the mall."

While Liotta's resume includes intense roles in such dramas as "Goodfellas," "Unlawful Entry" and "Hannibal," "Observe and Report" obviously shows the actor's willingness -- and ability -- to do comedy.

After all, he's far from being the hard case he's played so well in past roles, and knows very well that you can't take yourself too seriously in the movie business. He's even willing to lampoon his image, like he did as the proprietor of Ray Liotta honey in Jerry Seinfeld's animated hit, "Bee Movie."

"We're playing make-believe for a living. How serious can you take it?'" Liotta observed. "You have to take your job serious, of course, but at the end of the day, you're still playing pretend."