During his tenure as Minnesota Attorney General, the case "Gideon v. Wainwright" (which ultimately established the right of defendants in state courts to have a lawyer) was being heard by the U.S. Supreme Court. When those opposed to the right to counsel organized a Friend of the Court brief representing several state attorneys general for that position, Mondale organized a countering Friend of the Court brief from many more state attorneys general, arguing that defendants must be allowed a lawyer. He also continued the investigation of former Minneapolis mayor Marvin L. Kline and the mismanagement of the Sister Kenny Foundation.