Ex parte Quirin
Ex parte Quirin was a 1942 ruling by the Supreme Court of the United States that set precedents related to presidentially ordered military tribunals, conducting them in secret, and denying habeas corpus.  Richard Quirin and seven others were German agents, some captured in civilian clothing, who had been landed by submarine on the U.S. coast. They were trained and equipped to conduct sabotage.
Affirming the decision of the U.S. District Court for the District of Columbia, the Court held unanimously that the military tribunal that tried the agents, which had been established by presidential proclamation and staffed by presidential military order on July 2, 1942, was lawfully constituted and the prisoners' military detention was lawful.
Three of the prisoners had landed while wearing German uniforms, but buried them after landing; four others entered the United States in civilian clothing. They were charged pm July 3, 1942, the Judge Advocate General's Department of the Army prepared and lodged with the Commission the following charges against petitioners, supported by specifications:
- Violation of the law of war.
- Violation of Article 81 of the Articles of War, defining the offense of relieving or attempting to relieve, or corresponding with or giving intelligence to, the enemy.
- Violation of Article 82, defining the offense of spying.
- Conspiracy to commit the offenses alleged in charges 1, 2 and 3.
Citing, among other precedents, Ex parte Milligan, the Court did not address the guilt or innocence of petitioners. It affirmed Constitutional safeguards for the protection of all who are charged with offenses are not to be disregarded in order to inflict merited punishment on some who are guilty. It held that the "Constitution thus invests the President as Commander in Chief with the power to wage war which Congress has declared, and to carry into effect all laws passed by Congress for the conduct of war and for the government and regulation of the Armed Forces, and all laws defining and punishing offences against the law of nations, including those which pertain to the conduct of war." Legislation then in effect recognized recognize the "military commission", "appointed by military command as an appropriate tribunal for the trial and punishment of offenses against the law of war not ordinarily tried by court martial." Specifically, Congress' decision that military tribunals "shall have jurisdiction to try offenders or offenses against the law of war in appropriate cases" was constitutional.
The court was unanimous, 8-0  the Congressionally approved Articles of did not, at any stage, constitute grounds to issue a write of habeas corpus. Opinions differed, however, on the reasons. Some Justices did not believe the Articles of War governed a Presidentially-appoved tribunal, while others said it was within Presidential authority, but discretionary as to whether to use the courts or a commission.