In the United States, there is plentiful news of investigations of high profile people. In particular, some issues, like the Hillary Clinton Email Scandal have resulted in investigations from multiple political bodies.
Notwithstanding opinions on validity of an investigation or opinions on the issue I cited at hand, I was wondering about the following situation. Say two investigations, one from the Department of State and one from the DOJ, both organizations which are federal and operate under the same executive branch of the United States, determine someone is guilty and come up with an identical set of charges. These investigations are independent and have inherently different processes for handling things.
How would a trial proceed upon conclusion of these investigations, so as to prevent things like double jeopardy?