Laughton considered casting Gary Cooper as Harry Powell, but Cooper did not accept the role as he thought it might be detrimental to his career. John Carradine expressed interest in the role of the reverend, as did Laurence Olivier, but his schedule wasn't free for two years. Robert Mitchum was eager for the part of the preacher. When he auditioned, a moment that particularly impressed Charles Laughton was when Laughton described the character as "a diabolical shit," and Mitchum promptly answered "Present!" Laughton liked Mitchum for the role partly due to his sexual persona, but Grubb was concerned about the character of the preacher being considered sexual. Laughton told him, "If you want to sell God, you have to be sexy."