He should be available to answer questions, but unless a court has ordered something, he should be fine. It would help to contact a local attorney who does juvenile work.
So long as there is no order requiring him to stay, he can leave. Having practiced in this area in FL for several years, I can advise, however, that appearances are important: if it suddenly seems he's skipping town and he doesn't cooperate with CPS's investigation (NOT the criminal investigation-- that I'll address after), that may raise questions. As for the criminal investigation, it's always best to have an attorney at your side during any such interview.