Pretty simple case here. Native American grade A scumbag Jimcy McGirt got busted molesting a kid. However, this act occurred on land reserved for Native Americans by the federal government.
So Jimcy, trying anything imaginable to beat this heinous act, is trying to argue the state of Oklahoma doesn’t have jurisdiction here, since it occurred on federal lands. As such, state laws such as the one he’s accused of violating, do not apply to him on the reservation.
So now SCOTUS gets to decide if states can prosecute Native Americans committing major crimes on land reserved for native Americans by the federal government.
In a 5:4 majority (Ginsburg, Breyer, Sotomayor, Kagan, and Gorsuch), SCOTUS ruled that the Major Crimes Act gives the federal government the sole right to prosecute assholes like McGirt. That McGirt committed his crimes on federally-reserved Creek Nation land. That just because it wasn’t initially called a reservation, doesn’t mean it isn’t, and that Congress can’t just take away their land.