The Ox Bow Incident (1943).

Based on the novel.
In 1885 Bridger’s Wells Nevada two cowboys, Art CROFT and Gil CARTER, hitch up their horses and enter Darby’s Saloon. There, it is learned that local rancher Larry KINKAID has been murdered. The townspeople immediately form a large posse to pursue the murderers. Art and Gil join. DAVIES, fearing a lynching, also joins, hoping he can prevent such an occurrence. Major TETLEY dressed in an old Civil War uniform assumes leadership. His son Gerald comes with him. Soon news arrives that three men with cattle bearing Kinkaid’s brand have just entered Bridger’s Pass.
Later that night in Ox-Bow Canyon the posse find three men sleeping with what are presumed to be stolen cattle nearby. The posse interrogate them: A young, well-spoken Donald MARTIN; A Mexican, Juan MARTINEZ; And an old man Alva HARDWICKE who is clearly senile. Martin claims that he purchased the cattle from KINKAID but received no bill of sale. No one believes Martin, and the posse decide to hang the three men at sunrise as a final request, Martin writes a letter to his wife and asks Davies to deliver it. When dissent develops among some members of the group, a vote is taken on whether to hang the trio or take them to town to stand trial. Only seven vote for a trial. The rest support a hanging.
After the lynching, the posse returns to Bridger’s Wells. On the way, they encounter the town’s sheriff, RISELEY who reveals KINKAID is not dead and that the men who shot him have been arrested. RISELEY then asks DAVIES who is responsible for the lynching. “All but seven,” DAVIES replies, and the sheriff angrily declares, “God better have mercy on you. You won’t get any from me.” Later, the posse gather in Darby’s Saloon. In silence they listen as Gil quietly reads Martin’s letter aloud to Art. Meanwhile, Major TETLEY returns to his house, locks his son out, and commits suicide. In the end, Gil and Art head out of town to deliver the letter and $5ØØ raised by those in the posse for Martin’s wife.

Producer… Lamar TROTTI
Director… William A. WELLMAN

Cast
Henry FONDA… Gil CARTER
Dana ANDREWS… Donald MARTIN
Harry MORGAN… Art CROFT (as Henry MORGAN)
Frank CONROY… Major TETLEY
Harry DAVENPORT… Mr. Arthur DAVIES
Anthony QUINN… Juan MARTINEZ/Francisco MOREZ, The Mexican
Francis FORD… Alva HARDWICKE, The Old Man
William EYTHE… Gerald TETLEY
Mary Beth HUGHES… Rose MAPEN/Rose SWANSON
Jane DARWELL… “Ma” Jenny GRIER
Marc LAWRENCE… Jeff FARNLEY
Paul HURST… Monty SMITH
Chris-Pin MARTIN… Poncho
Leigh WHIPPER… Sparks (uncredited)
Stanley AANDREWS… Bartlett (uncredited)
Victor KILIAN… Darby, bartender
Matt BRIGGS… Judge Daniel TYLER
Willard ROBERTSON… Sheriff RISELEY
Dick RICH… Deputy Butch MAPES (uncredited)
George MEEKER… Mr. SWANSON, Rose’s husband (uncredited)
Billy BENEDICT… young man with news (uncredited)
Margaret HAMILTON… Judge TYLER’S housekeeper (uncredited)
Hank BELL… Red (uncredited)