Where the state wants to, it can press charges on its own. It's up to the prosecutors, generally. This is why there are cases like "so and so vs. New Jersey". In cases like murder and such, the state is the only viable prosecutor, which is why the prosecutor works for the state.

That said, I don't know the procedure for determining whether or not an actual crime has been committed, and without there being an actual case in hand, I have no idea if the subpoenas are valid.