Upon discovering that he contracted cancer coming back from the war, Rambo wanders aimlessly into town. He is greeted by a small town overzealous sheriff named Will Teasle, played wonderfully by Brian Denehy. He at first tells Rambo that he will help him out and give him a ride.
When Rambo asks if he can find a good place to eat, Teasle directs him to a diner about 10 miles up the highway. Rambo asks if there is a law against him eating in the town, Teasle, says yea, me. This sets up the premise as Rambo begins walking back into town. Arrested for vagrancy, Rambo is taken to the local jail and we meet some of the local redneck officers, notably, a young David Caruso, who seems to be the only one who empathizes with Rambo. Finally, he escapes the jail and takes the entire small town sheriff department and the military on a hunt into the local 'jungle.' First Blood has strength of character. It has frenetic action scenes and every actor in the film is at the top of their game.
Samuel Trautman, Rambo's mentor and former Colonel in the war, is played by Richard Crenna as a no nonsense but empathetic man. He knows Rambo has pushed back a little too hard but he understands where his plight comes from.
He wants to avoid more bloodshed but at the same time he doesn't completely agree with how Rambo has been treated. He is obviously a law abiding citizen, but he knows that not all the laws were upheld when dealing with Rambo. Sylvester Stallone is RAMBO. There is no one else that could play him.