Ohio Rev. Code § 109.02
The attorney general is the chief law officer for the state and all its departments and shall be provided with adequate office space in Columbus. Except as provided in division (E) of section 120.06 and in sections 101.55, 107.13, and 3517.152 to 3517.157 of the Revised Code, no state officer or board, or head of a department or institution of the state shall employ, or be represented by, other counsel or attorneys at law. The attorney general shall appear for the state in the trial and argument of all civil and criminal causes in the supreme court in which the state is directly or indirectly interested. When required by the governor or the general assembly, the attorney general shall appear for the state in any court or tribunal in a cause in which the state is a party, or in which the state is directly interested. Upon the written request of the governor, the attorney general shall prosecute any person indicted for a crime.
R.C. § 109.02