The local tribes here in western Washington that have gotten really fat from casinos purged a bunch that weren’t enough of their kind of Indian a while back. Greedy little devils.
I was working at a small tribal village. On all the public buildings they had a list of names of people banished from the tribe. Newer listings also had a post with the person’s photo and detailed explanation.
It seemed that most of the offenses were fairly minor, but repeated offenses. A good way to get rid of the chronic disorderly drunks and what have you. I’m guessing the more serious crimes were dealt with in prison or jail. I have no idea what happens if an Indian commits a serious crime on the reservation.