The U.S. Supreme Court case Duncan v. Kahanamoku, Sheriff (1945) revolved around the issue of whether or not military tribunals could try civilians in Hawaii during World War II without violating their constitutional rights. The court ruled 6-2 that two civilian workers who were tried and convicted by a military tribunal for public drunkenness and assault should have been tried in a civil court instead. This decision was based on the fact that martial law had been declared in Hawaii after the attack on Pearl Harbor but did not justify suspending civil liberties to such an extent as to allow military trials of civilians for non-military offenses when civil courts were still functioning.

In the dissenting opinion for Duncan v. Kahanamoku, Justice Murphy argued that martial law should not have been declared in Hawaii during World War II because there was no invasion or rebellion, and civilian courts were still able to function. He believed that the military had overstepped its authority by trying civilians in military tribunals when civil courts were available. Furthermore, he contended that Congress did not intend to suspend habeas corpus rights with the Hawaiian Organic Act of 1900 and therefore it was unconstitutional for these rights to be suspended under martial law without direct congressional approval. The majority's decision undermined basic constitutional protections against arbitrary government action according to him.