In their only joint film Sylvester Stallone and Robert DeNiro star in Cop Land, a story about Garrison, New Jersey a small town where an overabundance of NYPD officers reside. So much so that the place is called Cop Land and they have the run of the place.
As the official law in Cop Land the boys in blue have selected a wannabe. Sylvester Stallone who lost the hearing in one ear saving a drowning woman Annabella Sciorra is the police chief. Other than rescuing cats and issuing speeding tickets, but never to the NYPD residents of his town all Stallone does is stand in awe of the people who have the career he wanted.
This whole set up comes tumbling down during a shootout at the George Washington Bridge where Michael Rappaport shoots two black teens, two stupid ones I might add who point something at him he mistakes for an automatic weapon. The NYPD citizens of Cop Land do what they can to cover up the incident, but it all blows up in their faces.
Robert DeNiro who is an internal affairs detective has been looking into the cop residents of Garrison for some time. He tries to recruit Stallone, but Stallone has to see for himself what his 'friends' are really like.
Stallone does one of the best acting jobs in his career. He most assuredly is not playing super hero Rambo or even working class hero Rocky in this. He's a flawed man physically and emotionally and the Garrison NYPD colony don't take him seriously at all. That's part of their downfall.
Besides those already mentioned I would single out Harvey Keitel as the unofficial head of the Garrison cop colony. The more the story unfolds the more frightening Keitel becomes. Cathy Moriarty-Gentile as Keitel's abused wife, Ray Liotta who develops a conscience about what is going on and Frank Vincent as the police union head who is the ultimate target in the Cop Land probe from Internal Affairs.
But it's Stallone who is the real revelation here. It's a different Sly than fans of Rocky and Rambo know.