In Diaz v. United States, 1911, the U.S. Supreme Court ruled that a person could be tried and convicted for murder in federal court even if they had already been acquitted of the same crime in a state court without violating the Double Jeopardy Clause of the Fifth Amendment. The case involved Rafael Diaz who was accused of murdering William L. Simpson on board an American vessel anchored at Manila Bay during U.S.'s military occupation following Spanish-American War. He was first tried by a Philippine court and acquitted but later retried by an American federal court where he was found guilty and sentenced to death penalty which led him to appeal his conviction arguing it violated double jeopardy principles under U.S Constitution's Fifth Amendment rights.

In the dissenting opinion for Diaz v. United States, Justice Harlan argued that the defendant's constitutional rights were violated because he was tried and convicted in a U.S. court for a crime committed in another country (Mexico). He believed this case raised serious questions about national sovereignty and jurisdiction, as well as individual rights under the Constitution. According to him, it is not within the power of Congress to punish crimes committed outside of U.S territory unless explicitly provided by international law or treaty stipulations. Therefore, he disagreed with majority’s interpretation of an 1818 statute which allowed such prosecution on foreign soil if murder was committed against American citizens by other Americans abroad. In his view, this legislation did not apply to Diaz's case since it involved manslaughter rather than murder charges; hence its application constituted an overreach beyond what Congress intended when passing that law.