Md. Code, Courts and Judicial Proceedings § 12-201

Except as provided in § 12–202 of this subtitle, in any case or proceeding pending in or decided by the Appellate Court of Maryland upon appeal from a circuit court or an orphans’ court or the Maryland Tax Court, any party, including the State, may file in the Supreme Court of Maryland a petition for certiorari to review the case or proceeding. The petition may be filed either before or after the Appellate Court of Maryland has rendered a decision, but not later than the time prescribed by the Maryland Rules. In a case or proceeding described in this section, the Supreme Court of Maryland also may issue the writ of certiorari on its own motion.