Trial judges have discretion to decide when to conduct an inquiry. Ainsworth v. State, 493 S.W.2d 517, 521 (Tex. Crim. App. 1973). And, as the Texas Court of Criminal Appeals reaffirmed in Moore v. State, a competency hearing is not required unless the evidence is sufficient to create a bona fide doubt in the mind of the judge whether the defendant meets the test of legal competence. 999 S.W.2d 385, 393 (Tex. Crim. App. 1999). On appeal, the standard of review is whether the trial court abused its discretion by failing to empanel a jury for the purpose of conducting a competency hearing. Id. Article 46.02, section 2, requires the trial court to conduct a hearing in advance of a trial on the merits if, on its own motion or on written motion by the defendant or his counsel, the court determines there is evidence to support a finding of incompetency to stand trial. TEX. CODE CRIM. P. ANN. art. 46.02(2)(a) (Vernon Supp. 2000). Or if, during the trial, evidence of the defendant's incompetency comes to the court's attention from any source, the court must conduct a non-jury hearing to determine whether or not there is evidence to support a finding that the defendant is incompetent to stand trial. TEX. CODE CRIM. P. ANN. art. 46.02(2)(b) (Vernon 1989).