It’s important to note that these charges simply reflect the jurisdictional difference between federal employees and others. He will later be charged by the state for murder and attempted murder, it’s just going to be split that way to ensure conviction in one of the venues. They could have charged him federally for all the crimes, but splitting it up gives them virtual certainty of conviction on a murder charge.
The state charges will come years from now. In the meanwhile, the prosecution will be PR gold for the Justice Department and an opportunity for preening by Holder, Obama, and their media allies.