No such thing anymore! The feds are doing it all the time if the state charges do not stick.
Boy howdy! The state couldn't get a murder charge to stick on a racial slaying here maybe 15 years back, and the federal prosecutor popped the perp on "denying the victims their civil rights by killing them." They won the conviction.
The fed penalty for an ex-con posessing a weapon is tougher than the state... you guessed it. Project Exile to the rescue.