HockeXpert, you said,
"tribal police who are bound first by US law then tribal law"
Correction:
The tribes are NEVER bound by US Law, as they are SOVEREIGN nations.
There is a US Supreme Court Case from the 1970's where the Justices decreed that even constitutional protections (in that case "unreasonable search and seizure") do NOT apply on Indian Land.
I can post that here if there is interest.
One might note that the Seminole Casinos in Florida, according to the Florida Supreme Court's unanimous decision, are unlawful; yet their sovereignty completely protects them from Florida state law.
The single best example of Native American sovereignty that I know of was when (around 1986) New York's then Governor, Nelson Rockefeller, foolishly sent in the State Police to shut down the (then) unlawful casino operating on the Ste. Regis Reservation in northern N.Y. The Mohawks greeted the State Police with road blocks and a hail of gunfire in which some State police were wounded. The Attorney General quickly informed the governor that the State Police have no right to enforce any laws on tribal lands and that agents and officers of Federal, State, County, Municipal governments cannot so much as be present on their land without their permission.
Billboards stating that were erected on the eastern and western access roads, and were still present when last I was there.
Those signs explicitly refused access to the I.R.S. F.B.I. etc.
p.s. Federally recognized Native Americans tribes number > 550 with about 2.4 million members, who have been American citizens with voting rights since 1924. (New Mexico 1962)
State income taxes are not paid on reservation or trust lands.
"Tribal sovereignty describes the right of federally recognized tribes to govern themselves and the existence of a government-to-government relationship with the United States. Thus a tribe is not a ward of the government, but an independent nation with the right to form its own government, adjudicate legal cases within its borders, levy taxes within its borders, establish its membership, and decide its own future fate. The federal government has a trust responsibility to protect tribal lands, assets, resources and treaty rights."