Magnum, P.I. - Season 5 Episode 8
Murder 101

At the urging of the students in the private investigation class that Thomas is teaching at a local college, Thomas takes on the investigation into the disappearance of a fellow students fiancé as the classs field work. The teacher and his pupils soon discover that while the students fears that her fiancé is having an affair are unfounded, this anything-but-textbook case involves a man sought after by both sides of the law for trying to prevent a crime.