If, before or during a trial, the defendant in a criminal case or a violation of probation proceeding appears to the court to be incompetent to stand trial or the defendant alleges incompetence to stand trial, the court shall determine, on evidence presented on the record, whether the defendant is incompetent to stand trial. If, after receiving evidence, the court finds that the defendant is competent to stand trial, the trial shall begin as soon as practicable or, if already begun, shall continue. At any time before final judgment, the court may reconsider the question of whether the defendant is incompetent to stand trial.