The Squamish Indian Tribe (Tribe) (defendant) lived on the Port Madison Reservation, a conglomeration of land owned by the Tribe, by individual Indians, and by non-Indians. Under the Law and Order Code, the Tribe had jurisdiction over all crimes occurring on the reservation, whether committed by an Indian or by a non-Indian. Oliphant (plaintiff), a non-Indian resident of the reservation, was arrested and charged with assaulting a tribal police officer and resisting arrest. Oliphant objected to being tried in tribal court, arguing that the tribal court lacked criminal jurisdiction over a non-Indian resident. The Tribe argued that jurisdiction existed pursuant to the Tribe’s inherent sovereign authority. The district court denied Oliphant’s writ for habeas relief, and the ninth circuit affirmed. The United States Supreme Court granted certiorari. The tribal proceedings were stayed pending review.