Georgia Code Title 9. Civil Practice § 9-14-45

Service of a petition brought under this article shall be made upon the person having custody of the petitioner. If the petitioner is being detained under the custody of the Department of Corrections, an additional copy of the petition shall be served on the Attorney General. If the petitioner is being detained under the custody of some authority other than the Department of Corrections, an additional copy of the petition shall be served upon the district attorney of the county in which the petition is filed. Service upon the Attorney General or the district attorney may be had by mailing a copy of the petition and a proper certificate of service.