Frederick Manion, an Army lieutenant, is arrested for the murder of bartender Barney Quill. In his defense, he claims that Quill raped and beat up his wife Laura. Although Laura supports her husband's story, the police surgeon cannot find evidence of rape. Manion is defended by Paul Biegler, a humble small-town lawyer. During the course of interviews, Biegler discovers that Manion is violently possessive and jealous, and that his wife has a reputation for giving her favors to other men. Biegler realizes that the prosecution will try to make the court believe that Laura was the lover of the bartender and that Manion killed him and beat her up when he discovered them together. Manion pleads "not guilty" and Biegler, who knows that his case is weak, sets his assistants to try to find a witness who will save Manion.