Okla. Stat. tit. 22, § 1360

A. The System shall represent indigents in proceedings for postconviction relief in all capital cases. B. In noncapital cases, the System shall not be appointed to represent indigents in proceedings for postconviction relief; provided, however, the System may represent indigents in postconviction proceedings if the representation is related to another pending case in which the System has been appointed, or the proceeding is necessary to obtain an appeal out of time on behalf of a System client in a case to which the System has been properly appointed. C. No attorney employed by the System or providing legal services for the System pursuant to contract shall be required to appear in the district courts of this state on issues of appellate counsel appointment and requests for exhibits, records and transcripts. D. After a mandate has been issued by the Oklahoma Court of Criminal Appeals in any case on direct appeal, the System is prohibited from appealing that case in any further proceedings in either a state or federal court, except in capital cases and in cases provided for in subsection B of this section. In capital cases, the System shall perfect all petitions for writ of certiorari to the United States Supreme Court and represent such appellants or appellees, as the case may be, in any appearance before that Court.