A true story is the inspiration for a gritty crime drama co-starring veteran screen star Robert DeNiro and rising young actor James Franco as an estranged father and son. Alan Silverman has a look at City By The Sea.

Decorated and respected New York City police detective Vincent LaMarca has come a long way since his troubled childhood in Long Beach, an oceanfront community not far from the city. A murder investigation takes him back to the now decaying town where the evidence points to the son he hasn't seen or spoken with in years.

Moral choices and family loyalty clash as the father and son, coming from opposite sides of the law, are drawn together. Robert DeNiro says the drama is made all the more compelling drama because it actually happened to the real detective Vincent LaMarca and his son, Joey.

"The real part of it made it, of course, more interesting," says DeNiro, " but what I was taken by was the script, because no matter who you do a story about... it could be about Christ... if the script is not there, then there's nothing. Everybody wants to make a story about this and that, ' I have a life story and it's great....' But if you have the script. That was the most important thing."

"He was a cop, but also it was about a guy who was in a situation that you can empathize and sympathize with and relate to, " explains DeNiro. " I could. So he was a cop, yes, and that's part of the whole structure of the thing, but it's not the essence of it. It's about what happens with a father and son, the father not being there and giving up at one point and forced to go back because of what he does. It's about facing it and supporting his son and having a reconciliation of sorts ... a rapprochement of whatever."

James Franco co-stars as Joey and the 24-year-old rising star says he had to confront the character's homeless lifestyle and debilitating drug addiction.

"I went to a lot of treatment centers in L.A. and New York and some of them had experience with research for movies before, so they were willing to help," he explains. " The people in the treatment centers were more than willing to tell the stories of what it's like to live that kind of life. As far as the homeless part, as an experiment I spent a couple of weekends homeless and without any money. I went with a friend and we dirtied ourselves up just to see what it's like in that kind of life. People treated me differently. It's like you're in a different world even though you're in the midst of plenty of people."

Director Michael Caton-Jones found dilapidated oceanfront buildings (in another "City by The Sea," Asbury Park, New Jersey) to give an added sense of realism.

"For me it's very important where a film is set," he says. " I believe you can influence the emotions if you choose carefully the backdrops because nothing happens in a vacuum anyway. In this case it was very important for me to try to reflect his emotional journey. When he was a child living with his parents in Long Beach, the place was wonderful. Since then, as life has changed, so has the place."

The screenplay for City by the Sea is by Ken Hixon. The cast also features Frances McDormand, Eliza Dushku and Patty Lupone.