If there is proof that Guardians furnished alcohol to a minor, that is criminal. You should talk to police about that. How do you know he was given the alcohol by the guardian? Taking his word for it? Talk to the lawyer who is helping you in the juvenile court matters, or get one asap to help.
This sounds like a very disturbed child. I think he needs counceling but I really don't see where the county is liable. A very troubling situation.
Sign up to receive a 3-part series of useful information and advice about personal injury law.