It would be very difficult because of the double jeopardy law and I seriously doubt they will. However, because of the dual sovereignty doctrine, the feds could technically try little miss thing without violating the double jeopardy laws. That is because the state of Florida and the federal government are seen as two separate entities. Each considers murder to be a punishable crime and each can prosecute one time for murder. Anything could happen. If Casey admits to this or new evidence pops up, new charges could be brought. There is also the question of prosecuting her for violating the civil rights of a child. That is certainly a possibility and she could get life if convicted of that charge. A federal charge I might add.