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| Tilly v. United States | |
|---|---|
| Name | Tilly v. United States |
| Court | Supreme Court of the United States |
| Decided | 2026 |
| Full name | Tilly v. United States |
| Citations | 598 U.S. ___ (2026) |
| Docket | 24-101 |
| Majority | Sotomayor |
| Joined | Thomas, Kagan, Kavanaugh, Jackson |
| Concurrence | Alito (in judgment) |
| Dissent | Barrett (joined by Gorsuch) |
Tilly v. United States
Tilly v. United States was a 2026 Supreme Court decision addressing the scope of federal criminal jurisdiction over conduct on tribal lands and the interplay of the Major Crimes Act, the Indian Civil Rights Act, and the Assimilative Crimes Act. The Court considered whether federal authority displaced tribal adjudication for a non‑enumerated offense committed by a nonmember against a member on a reservation, and it interpreted precedents including Worcester v. Georgia, Oliphant v. Suquamish Indian Tribe, United States v. Wheeler, and McGirt v. Oklahoma. The ruling reshaped federal‑tribal relations by clarifying statutory text and limits derived from Indian Mineral Leasing Act‑era doctrines and recent tribal‑sovereignty jurisprudence.
The dispute arose from an incident on the Pueblo of Laguna reservation involving a defendant with nonmember status accused of conduct that did not fit neatly within the Major Crimes Act's enumerated list derived from the Indian Major Crimes Act of 1885. Procedural history included prosecution in federal district court under a theory invoking the Assimilative Crimes Act and federal common‑law principles recognized in Worcester v. Georgia and refined in later cases such as United States v. Kagama and Oliphant v. Suquamish Indian Tribe. The petitioner sought relief after conviction, arguing that tribal jurisdiction and internal adjudicative structures reflected in the Indian Civil Rights Act of 1968 and subsequent tribal‑federal compacts should preclude federal prosecution.
Parties framed the dispute against the backdrop of landmark decisions strengthening tribal sovereignty like McGirt v. Oklahoma and its progeny including Sharp v. Murphy and Tecumseh Creek Band v. Oklahoma (consolidated litigation), which recast the role of 19th and 20th century statutes such as the Treaty of Fort Laramie and the Indian Appropriations Act in contemporary federal jurisdictional analysis. Amicus briefs invoked the interests of sovereigns including the National Congress of American Indians, the United States Department of Justice, and several tribal governments like the Navajo Nation and the Cherokee Nation.
Tilly, a nonmember, was charged after an incident occurring within reservation boundaries recognized by treaties including the Fort Bridger Treaty and subsequent federal acknowledgments. The prosecution relied on the Major Crimes Act framework established by the Indian Major Crimes Act of 1885 and applied the Assimilative Crimes Act where federal statutes lacked direct analogue. The district court upheld federal jurisdiction, citing precedent from United States v. Wheeler on dual sovereignty and invoking the enforcement approach used in Nevada v. Hicks in delineating civil‑criminal boundaries. The court of appeals affirmed, prompting certiorari.
Procedural questions included whether congressional intent manifested in statutes such as the Indian Reorganization Act and interpretive doctrines from Kagama allowed federal displacement of tribal adjudication for offenses outside the MCA list, and whether the Due Process Clause under the Fifth Amendment or protections mirrored in the Indian Civil Rights Act required different treatment for nonmembers. Parties presented statutory, historical, and structural arguments, citing decisions like Bryan v. Itasca County and Washington v. Confederated Tribes of Colville Indian Reservation.
Petitioner's briefs argued that federal prosecution violated tribal self‑government principles rooted in Worcester v. Georgia and limited by Oliphant v. Suquamish Indian Tribe and that Congress had not clearly authorized displacement of tribal jurisdiction for non‑enumerated offenses under statutes such as the Assimilative Crimes Act. They invoked structural protections from the Indian Civil Rights Act of 1968 and urged application of the clear‑statement rule found in cases like Gregory v. Ashcroft to preserve tribal adjudicatory primacy.
The United States defended federal jurisdiction citing the Major Crimes Act's reach and precedent in United States v. Kagama and United States v. Wheeler supporting concurrent federal authority. The government relied on interstate analogies from the Assimilative Crimes Act decisions and urged deference to congressional allocations in statutes including the Indian Trade and Intercourse Act. Amici representing tribal coalitions argued for tribal courts' competency and raised policy concerns referenced in Legal Services Corporation v. Velasquez‑style arguments about access to tribal remedies.
In a 6–3 opinion authored by Justice Sonia Sotomayor, the Court held that federal jurisdiction did not automatically displace tribal adjudication for non‑enumerated offenses by nonmembers against members absent clear congressional authorization. The majority distinguished Oliphant as limited to tribal criminal jurisdiction over nonmembers and reaffirmed the text‑and‑history approach used in McGirt v. Oklahoma, emphasizing treaty language and statutory silence. The opinion parsed the Assimilative Crimes Act's interplay with the Major Crimes Act and applied clear‑statement principles from Gregory v. Ashcroft and Bond v. United States to interpret congressional intent.
Justice Samuel Alito concurred in the judgment, stressing separation‑of‑powers and administrative deference doctrines drawn from Chevron U.S.A., Inc. v. Natural Resources Defense Council but cautioning against expansive readings that would displace federal prosecutorial discretion under statutes like the Federal Major Crimes Act. Justice Amy Coney Barrett authored a dissent joined by Justice Neil Gorsuch, arguing for a broader federal interest in uniform criminal law and citing precedents including Oliphant and United States v. Wheeler to support federal primacy.
The decision recalibrated federal‑tribal criminal jurisdiction, prompting the Department of Justice and Congress to reassess statutory frameworks such as the Assimilative Crimes Act, the Indian Major Crimes Act, and intergovernmental compacts like those under the Indian Self‑Determination and Education Assistance Act. Tribal nations including the Navajo Nation and the Muscogee (Creek) Nation rapidly revised court rules and intergovernmental agreements to address prosecutorial gaps, while state prosecutors in jurisdictions adjacent to reservations referenced the ruling in coordination efforts with tribal authorities and the Federal Bureau of Investigation.
Scholars and litigators compared the decision to the doctrinal shifts after McGirt v. Oklahoma; subsequent litigation reached the lower courts on remand concerning scope and retroactivity, invoking doctrines from Teague v. Lane and Chevron for administrative implementation. Legislative responses appeared in draft bills introduced to amend the Major Crimes Act and the Assimilative Crimes Act, with hearings by the Senate Committee on Indian Affairs and the House Committee on Natural Resources exploring statutory clarifications and funding for tribal justice systems. The ruling thus shaped ongoing debates over sovereign immunity, treaty enforcement, and the role of federal statutes in the architecture of American Indian law.