Puerto Rico v. Sanchez Valle

The Puerto Rico double jeopardy case orals often dwelt in broad terms regarding sovereignty (the SCOTUS' power to take the case now was not addressed) but it might not be necessary. A middle ground might be that the grant of self-rule is interpreted to (without a clear statement otherwise) to assume enough sovereignty for double jeopardy to not arise. As noted at one point, federal criminal law can be crafted to get to the same point anyways.