Ft Apache: The Bronx
(1981)

The prostitute who killed two policemen in the first scene is killed by a couple of drug dealers she attacks. They wrap her in a carpet and leave her on a landfill.

The same drug dealers kill Murphy's girlfriend with a calculated heroin overdose. The police never get any clues about any of these crimes. Then, the drug dealers hold a dozen of doctors and nurses hostage at the hospital. Murphy and Corelli rescue them, killing the dealers in the process.

After finding his girlfriend dead, Murphy tells on Morgan, another policeman who threw a boy from a roof. He wants to resign as a policeman, but eventually doesn't.

The film ends with Murphy and Corelli running after a boy who has committed several petty crimes during the film.

Thanks Eugenia!