When a district attorney is recused, or recuses himself, the trial judge shall either appoint an attorney at law, who has the qualifications of a district attorney and is not an assistant to the recused district attorney, to act in the place of the district attorney in the case, or shall notify the attorney general in writing of the recusation. In the latter instance, it shall be the duty of the attorney general to appoint a member of his staff or a district attorney of another district to act in the place of the recused district attorney. The substitute appointed for the recused district attorney shall have all powers of the recused district attorney with reference to the case.