Texas Code of Criminal Procedure - CRIM P Art. 4.04. Court of Criminal Appeals

Sec. 1. The Court of Criminal Appeals and each judge thereof shall have, and is hereby given, the power and authority to grant and issue and cause the issuance of writs of habeas corpus, and, in criminal law matters, the writs of mandamus, procedendo, prohibition, and certiorari.  The court and each judge thereof shall have, and is hereby given, the power and authority to grant and issue and cause the issuance of such other writs as may be necessary to protect its jurisdiction or enforce its judgments.

Sec. 2. The Court of Criminal Appeals shall have, and is hereby given, final appellate and review jurisdiction in criminal cases coextensive with the limits of the state, and its determinations shall be final.  The appeal of all cases in which the death penalty has been assessed shall be to the Court of Criminal Appeals.  In addition, the Court of Criminal Appeals may, on its own motion, with or without a petition for such discretionary review being filed by one of the parties, review any decision of a court of appeals in a criminal case.  Discretionary review by the Court of Criminal Appeals is not a matter of right, but of sound judicial discretion.