In 1995, a Pittsburgh, PA. teenager allegedly burned down his home at his mother's request to get the insurance proceeds. Three firefighters died fighting the blaze. A combination of local, state, and federal prosecutors form a joint prosecution team to try the teenager in state court and he's convicted and sentenced to life in prison. Two decades later, the state courts vacate the convictions and grant him a new trial because witnesses paid $5,000 and $10,000 respectively by the ATF for their trial testimony were not disclosed to the defense. The state (fine, the "Commonwealth") dismisses all charges. Justice! Wait, the United States wants to try him again for the same offense but this time in federal court. Man: Double jeopardy, right?! Third Circuit: Nope. The state case was set aside so double jeopardy doesn't factor.
The case is United States v. Brown, 20-1734 (3d Cir. Apr. 13, 2021).