(a) If a court holds a trial to determine whether the defendant is incompetent to stand trial, on the request of either party or the motion of the court, a jury shall make the determination.
(b) The court shall make the determination of incompetency if a jury determination is not required by Subsection (a).
(c) If a jury determination is required by Subsection (a), a jury that has not been selected to determine the guilt or innocence of the defendant must determine the issue of incompetency.