(1) Prosecute and defend on the part of the State all cases pending in the appellate courts of the State, in the Supreme Court of the United States or the inferior Federal Courts, by or against the State, or in which the State may be interested, except those criminal appeals otherwise prescribed by the General Assembly.

(2) Investigate, commence, and prosecute or defend any civil or criminal suit or action or category of such suits or actions in any of the Federal Courts or in any Court of this State, or before administrative agencies and quasi legislative bodies, on the part of the State or in which the State may be interested, which the General Assembly by law or joint resolution, or the Governor, shall have directed or shall direct to be investigated, commenced and prosecuted or defended.

(3) When required by the General Assembly by law or joint resolution, or by the Governor, aid any State's Attorney or other authorized prosecuting officer in investigating, commencing, and prosecuting any criminal suit or action or category of such suits or actions brought by the State in any Court of this State.

(4) Give his opinion in writing whenever required by the General Assembly or either branch thereof, the Governor, the Comptroller, the Treasurer or any State's Attorney on any legal matter or subject.