In the case of Hannah et al. v. Larche et al., the U.S Supreme Court ruled that a Commission established by Congress to investigate voter discrimination did not have to disclose its evidence or inform witnesses of their alleged offenses before questioning them. The plaintiffs, who were subpoenaed by the Commission on Civil Rights, argued that this violated their Fifth Amendment rights against self-incrimination and due process under law as they were not informed about what specific charges they faced nor allowed access to investigative files prior to testimony. However, the court held in an 8-1 decision that since the commission was purely investigatory and had no power to adjudicate legal rights or impose penalties, it was not required to follow traditional rules of procedure and evidence applicable in courts of law.

In the dissenting opinion for Hannah et al. v. Larche et al., Justice William O. Douglas argued that the Civil Rights Commission, as established by Congress, was not given authority to conduct investigations without providing due process rights to those under investigation. He believed that this violated constitutional principles of fairness and justice because it allowed for potential abuse of power without any checks or balances in place to protect individuals' rights against self-incrimination or defamation. Furthermore, he contended that such a broad grant of investigative powers could lead to an erosion of civil liberties if left unchecked by judicial review and oversight.