The Rifleman (1958) : 1x18

Abel Goss, the photographer who took Lucas' wedding photograph, is in North Fork doing a portrait of Mark standing in the street. When Goss sees Col. Whiteside and his sidekick Jamison, he recognizes them as the butchers who tortured him and others while he was captive in their prisoners of war camp. When Lucas stops him from killing them, Goss swears to kill those men. Whiteside planned to call Goss out, but he had Jamison shooting from the upstairs hotel window, as his insurance. When the shots are fired, Whiteside is dead, shot in the back, and his gun hadn't been fired. Goss is arrested and at the trial Lucas and Mark have different testimonies. Mark reenacts the scene in the street, and Lucas backs Mark's theory , using the photographic negative Goss had shot of Mark.