25 C.F.R. § 12.22 Can Bureau of Indian Affairs law enforcement officers enforce tribal laws?
Title 25 - Indians
BIA officers will enforce tribal laws only with the permission of the tribe. Local programs are encouraged to make arrangements and agreements with local jurisdictions to facilitate law enforcement objectives.
Title 25: Indians
PART 12—INDIAN COUNTRY LAW ENFORCEMENT
Subpart C—Authority and Jurisdiction
§ 12.22 Can Bureau of Indian Affairs law enforcement officers enforce tribal laws?

