The article mentioned that he is Navajo. I am not familiar with law concerning tribal crime. Do the tribes have their own courts? If this happened on the reservation, who has jurisdiction?
It varies. A lot depends on who was involved, what the crime was, and where it occurred. The Major Crimes Act defines certain crimes by Natives against Natives that are under federal jurisdiction. In this case, a double-kidnapping, a possible rape, and a murder, it would be federal.
My understanding is that serious crimes are adjucated in the white mans courts.