Almost every DAs office receives federal money of some kind. Since money is fungible, it stands to reason that some federal funds are utilized in this case. That could give Congress a reason to investigate. Accepting federal funds always comes with strings…
You send the itemized budget to the GAO and if there is an issue of criminal elements get the DOJ/FBI to come at them, either way, Congress (Only HOR in this case) bye-bye along with piss off, Division of Power and all that.