Terror on Highway 91 (1989)

Deputy Clay Nelson is a young deputy who got the job he always wanted, a police officer for his town. But soon after he begins, he learns of the ways in which his sheriff operates. While he endeavors to be honest and dedicated in his job, the other cops engage in graft and torture of the accused, among other things, while the sheriff acts like he is above the law. Eventually, Clay's patience for this mockery of justice reaches the breaking point and he must do something to stop it.