In the Line of Duty: Street War (1992)

In this gritty cops-and-crooks drama, two detectives hunt a gang leader suspected of murdering a New York cop. The detectives enlist the help of the dead cop's partner, who is also the brother of the gangster. There's nothing civil about this war that has two brothers squaring off against each other. The strong cast includes Mario Van Peebles, Ray Sharkey and Peter Boyle.