In the State of Georgia is it criminal for a relative trustee to steal from the relative beneficiary's trust fund?

Theft is theft, so yes, if your brother stole from your trust then he can be held criminally responsible. He could also be held personally responsible for the stolen assets, plus damages, in civil court, for breaching his fiduciary duty as a Trustee. You will need to contact the police about a criminal case, and an experienced estate and trust litigation attorney for a civil case. Best wishes to you- that's a terrible thing to have happened. It goes to show why selecting a Trustee can be such a critical issue.