Guilty Bystander is a 1950 American crime drama film noir directed by Joseph Lerner, and starring Zachary Scott and Faye Emerson.

It also marked the last motion picture screen appearances for character actors Mary Boland and J. Edward Bromberg.

The drunken Max confronts pistol packing Dr. Elder, looking for answers regarding his missing son, but the doctor knocks him out cold from behind.

Now sober, Max learns that the doctor was involved in a diamond smuggling operation with Varkas, a known criminal.

He learns from Varkas' helpful moll, Angel, that the gangster's men are holding Fred hostage.

He wrote, "Zachary Scott acts his butt off, but can't come close to saving this uninteresting film noir melodrama from how ordinary it is.