It is my understanding (and I may be wrong) that the federal murder charge is limited to Judge Roll and requires proof that he was "engaged in official duties" when he was murdered.
The Arizona state murder charges will be tried in Arizona. The state charges may be moved out of Tucson but cannot be moved out of the state. I hope they try them one at a time. Six possible death penalties.
The Federal charges are for the Federal employees that were on-duty, the Public Outreach Director that was killed, for example. Unfortunately, the Federal charge concerning the Judge will eventually be dismissed because, as Obambam spilled the beans in his Universe-wide speech the other night, he was just passing by to visit after Morning Mass.
He was not engaged in official duties, and everybody in the Universe now knows that, thanks to Odumbo.