Proximity (2001)

When William Conroy (Rob Lowe), a former college professor, is sentenced to life in prison for vehicular manslaughter it seems his life is over. But when a fellow inmate tells him that in the past two years fourteen inmates have died at the prison, and then turns up dead the next day, Conroy realizes he is in more danger than he ever imagined. Conroy's suspicions are confirmed when the van carrying the inmates crashes. Seizing the opportunity, Conroy flees the scene and elicits the help of his lawyer. What the two discover is a grisly murder ring set up within the prison walls that incriminates those at the highest levels of the correctional system.