This morning in McClain County, a district court is taking the first steps toward possibly applying the Supreme Court's landmark McGirt decision to another tribe: The Chickasaw Nation.

The court is holding a hearing in the case of Shaun Bosse, who is appealing his conviction for killing a mother and her two young children in 2010.

Bosse argues that because the family was Chickasaw and the crime happened on historically Chickasaw land, the state should not have been able to prosecute him.

Under federal law, if such a crime occurs involving Indians in Indian Country, it is prosecuted by the feds

So - the judge is charged with deciding -- is the Chickasaw Nation currently Indian Country?

In McGirt, the US Supreme Court found that, for purposes of federal law, the Muscogee (Creek) Nation is, in fact, Indian Country.

So, under the McGirt framework that was applied to the MCN, the judge in this case will have to decide

(a) whether the Chickasaw Nation once had a reservation,

and, if so,

(b) whether Congress explicitly disestablished that reservation

If the answer to (a) is "yes" and (b) is "no," then, for the purposes of federal law, the Chickasaw Nation has a reservation -- which is Indian Country for the purposes of federal law.

That is expected to be the conclusion. In fact, McGirt is expected to apply to all Five Tribes.

But we will await the district court's ruling, which is due in less than two months.

That ruling will then be sent up to the state's top criminal appeals court for further proceedings.

The Chickasaw Nation has joined as joined the hearing as an amicus curiae solely "in support of the continued existence of the Chickasaw Reservation and its boundaries"