Why did the police kill Sal? No one had been hurt or killed, and he wasn't actively threatening anyone in such a way that would warrant them shooting, it seemed to me. Not to mention, they had clearly been planning to shoot him for a good while beforehand.
The real-life "Sonny," John Wojtowicz, said in an article that the real Sal had in fact been killed by the FBI when they were caught. What was the justification for killing him? If he was shot down in cold blood (like the way it appeared in the film), weren't there any consequences?