SCOTUS ruled 6-3 on Mon. that Native Americans prosecuted in some tribal courts can be tried for the same incident in federal courts, which can result in harsher sentences.
The case involved a Navajo Nation member, Merle Denezpi, who pleaded guilty to assault and battery in a Court for Indian Offenses (CFR), and was sentenced to 140 days in the Ute Reservation.
This ruling couldn't be more wrong. The CFR isn't a tribal court but an extension of the federal government through the Department of the Interior. In a false claim of protecting tribal sovereignty, Denezpi has been prosecuted twice for the same crime.
SCOTUS is merely upholding the law and ensuring fair punishment. There is a clear distinction between the tribal courts and federal courts, without which defendants would be protected under the Double Jeopardy clause and allowed to escape appropriate sentences.