Here are the merits briefs:
Here are the amicus briefs supporting petitioner:
19-1414 Amicus Brief of NationalIndigenousWomensResourceCenter
19-1414 Indian Law Scholars Cooley Brief
19-1414 tsac Former U.S. Attorneys
19-1414 tsac Members of Congress
19-1414 tsac The Cayuga Nation
Final NCAI-Tribal Governments Amici Brief-US v Cooley 1-15-21
Here are the amicus briefs supporting respondent:
19-1414 Amici Curiae Brief Ninth Circuit Federal Defenders
National Association of Criminal Defense Lawyers Amicus Brief
Here are the cert stage materials:
Respondent Brief in Opposition to Petition for a Writ of Certiorari
Here are the Ninth Circuit materials:
Here are the district court (D. Mont.) materials: