There is no federal statute that defines who is an Indian. However, there are a number of federal court decisions that
do so. In modern usage, the legal term "Indian" usually means an enrolled member of a federally recognized tribe (or one who
is eligible to be enrolled in a federally recognized tribe). Each tribe has the sovereign authority to define who their members
are and who is eligible to be enrolled. Some tribes have blood quantum requirements (a requirement that to be enrolled, a
person must have at least a certain degree of tribal ancestry - such as one-fourth) while other tribes' laws state that a
person is eligible for enrollment if one of their ancestors appears on a particular historical list of tribal members. Ultimately,
the question of, "Who is an Indian?", is determined by tribal law. Usually, this determination can be made by contacting the
tribe and asking the enrollment clerk if a particular person is an enrolled member. In unclear cases, the tribal court may
have to decide and issue an opinion as to a particular person's status. For purposes of criminal jurisdiction, members of
all federally recognized tribes are "Indians" regardless what tribe's territory they may be present on (25 USC 1301(2); US
v. Lara, 541 US 193). For example, an enrolled member of the Cherokee Nation is an "Indian" not only on Cherokee
Nation lands but also on Navajo Nation land, and on the reservation of any other federally recognized tribe.
person is not enrolled nor eligible for enrollment in a federally recognized tribe, then he or she is probably not an "Indian"
for criminal jurisdictional purposes. Enrolled members of tribes recognized by a US state (but not by the federal government)
and indigenous people from Canada, Mexico, and other foreign nations are not considered to be "Indians" for criminal jurisdictional
purposes. This is because persons who are not members of federally recognized tribes in the US, do not have a special legal
relationship with the US government. In Morton v. Mancari (417 US 535) and US v. Antelope (430 US 641), the US Supreme Court
ruled that Indians can be treated differently under the law, not because of their race or ancestry, but because of their unique
political status under federal law.
PL-280 And Other Jurisdictional Transfers