What type of prejudice showing is required to obtain dismissal under Fed. R. Crim. P. 48(b) for delayed federal prosecution after state conviction?

QUESTION PRESENTED In Gamble v. United States, 138 S. Ct. 2707 (2018), this Court is considering whether the separate sovereign exception to the Double Jeopardy Clause should be overruled. The Ninth Circuit below held that although petitioner’s federal charges were “based on the same conduct underlying his Nevada state conviction . . . the ‘dual-sovereignty doctrine’ provides that the Double Jeopardy Clause does not bar successive state and federal prosecutions ‘for the same course of conduct’” and it could not “ignore binding Supreme Court precedent.” If this Court overrules the separate sovereign exception, it should grant this petition, vacate the decision below, and remand for further consideration in light of Gamble. Even if this Court does not overrule the separate sovereign exception in Gamble, that does not mean that a defendant should be without recourse under non-constitutional authority, and this Court should still grant this petition to address the following related question: What type of prejudice showing, if any, is required to obtain dismissal under Fed. R. Crim. P. 48(b) when the federal government files criminal charges approximately six years after the offense and more than two years after the defendant completed a prison sentence imposed by a state court for the same course of conduct. i