Hangmen was Brecht's only American film credit, although he supposedly worked on other scripts during his time in Hollywood, without receiving credit. He left the United States shortly after testifying before the House Un-American Activities Committee. John Wexley received sole credit for writing the screenplay after giving evidence to the Writers Guild that Brecht and Lang had only worked on the story. However, it seems that there is more Brecht in the script than is commonly accepted: the academic Gerd Gemünden writes that he spoke to Maurice Rapf, the judge on the case, who told him "it was obvious to the jury that Brecht and not Wexley was the main author, and that Wexley furthermore had a reputation as a credit stealer. It was only because of the fact that only written evidence was admissible, and since only Wexley's name appeared on all drafts, the jury had to rule in his favor." Wexley himself was blacklisted after he was named a communist in HUAC hearings.
