The Ox-Bow Incident (1943)

Everyone in the dusty nowhere town has been hearing about the rustling that's been going on, but when one of their own cattlemen winds up dead it gets personal fast.

Just a simple movie about how hard it is to stop a group once it gets going in a certain direction...and how scary such a group can be, regardless of whether you're on the outside or part of it. A tight screenplay (less than 80 minutes) that packs quite a wallop.

A+