Denezpi was prosecuted in the Court of Indian Offenses, a creature of the federal Bureau of Indian Affairs that provides a criminal court system for those (relatively few) tribes that haven’t set up their own. After serving a 140-day sentence in that prosecution, he was charged for and convicted of the same conduct in federal court—and ultimately given a 30-year sentence. The Supreme Court rejects his claim that the second prosecution was barred by the Double Jeopardy Clause.
The majority resolves Denezpi’s claim using the “dual sovereign” doctrine, which holds that prosecutions by two different sovereigns (typically, the federal government and a state) aren’t the “same offense” for purposes of the Fifth Amendment’s Double Jeopardy Clause. While the machinery of prosecution of the first case—the Court of Indian Offenses—is indeed a creation and part of the federal government, it is a federal government agency exercising tribal sovereignty for the tribe. (Slip op. at 4-6). The majority acknowledges this case presents a “twist” of one sovereign enforcing provisions of another sovereign’s laws (slip op. at 1), rather the typical situation of two separate sovereigns using their separate sovereign court systems to enforce their own law. But what matters for the “same offense” text of the Fifth Amendment is which sovereign’s law is being enforced. Here, Denezpi’s two prosecutions were premised on the law of two different sovereigns, so they are not prosecution for the “same offense.” (Slip op. at 8-12).
A dissent (Gorsuch, joined in large part by Sotomayor and Kagan) asserts the dual sovereign doctrine is not consistent with the text and original meaning of the Fifth Amendment. (Gorsuch said the same thing in his dissent to the recent case reaffirming the doctrine, Gamble v. United States, 587 U. S. ___, 139 S.Ct. 1960 (2019), though he was not joined by the other two dissenters in that case). But even under that doctrine, the history and structure and governing law of the Courts of Indian Offenses establish was historically, and remains today, “a federal scheme” (dissent at 11) that involves prosecutions under federal law, and thus Denezpi was prosecuted by the same sovereign in both of the prosecutions in violation of the Clause.