The Substitute (1995)

Synopsis
An ex-mercenary (Tom Berenger) becomes a take-no-prisoners teacher in a drug-ridden, gang-infested Miami high school in this campy morality tale about restoring lost American virtues to the inner city. Berenger's character, Shale, has no first name, a shadowy past as a patriotic gun-for-hire, and is temporarily unemployed and living with an idealistic teacher, Jane Hetzko (Diane Verona). Jane has angered a school gang leader, Juan Lucas (Marc Anthony), by asking the principal to get him transferred after he has threatened her in the schoolyard. After Jane is kneecapped by a gang member, Shale fakes a resume and becomes a substitute teacher, Mr. Smith. He lectures his class on the lessons of Vietnam ("We were fighting Communism") while looking for a way to get revenge on Juan. When he challenges the school's tolerance for student misbehavior, Smith is fired by the slimy principal, Claude Rolle (Ernie Hudson), an ex-cop who is running for City Council and doesn't want to rock the boat. Shale stays because he cites a union rule requiring two weeks' notice. During that period, tensions escalate and eventually Shale intervenes in a gang war that degenerates into a school-destroying inferno of violence. ~ Michael Betzold, All Movie Guide