I respectfully dissent from that part of the majority opinion in this case concluding that the trial court did not err in refusing to order a competency evaluation of William Joseph Bums upon motion of his counsel during his trial for the capital murder of Tersey Elizabeth Cooley and other related felony crimes. I concur in all respects with the remainder of that opinion.
Beyond question, the conviction of a legally incompetent defendant violates that defendant’s constitutional right to a fair trial. Drope v. Missouri, 420 U.S. 162, 171-72 (1975). In that regard, the issue in the present case does not involve an insanity defense which would concern Bums’ mental state at the time these crimes were committed. Nor does the issue involve a final determination that Bums was, or was not, incompetent to stand trial at some point during this trial. Rather, the narrow issue is whether, under the facts of this particular case, Bums was improperly denied a competency evaluation pursuant to Code § 19.2-169.1(A) so as to ensure that he received a fair trial. See Drope at 181-82 (due process violated when trial court failed to make further inquiry into defendant’s competency during trial).
*347In pertinent part, Code § 19.2-169.1(A) provides that: “If, at any time . . . before the end of trial, the court finds, upon hearing evidence or representations of counsel for the defendant. . . that there is probable cause to believe that the defendant lacks substantial capacity to . . . assist his attorney in his own defense, the court shall order that a competency evaluation be performed.” (Emphasis added). The probable cause standard in this statute is the familiar objective one requiring less than a preponderance of the evidence. Thus, where the circumstances of a particular case would reasonably cause doubt with respect to the defendant’s substantial capacity to assist his attorney in his own defense, this statute mandates, as is constitutionally required, that the trial judge order an evaluation of the defendant’s competency. This statute does not give the trial judge the discretion as to whether to order that evaluation. Accordingly, our review of the trial judge’s denial of the motion by Bums’ counsel for a competency evaluation pursuant to this statute involves consideration of the objective circumstances known to the trial judge at the time of his ruling, and not the trial judge’s subjective beliefs regarding Bums’ competency.
Although reflected only in a footnote in the majority opinion, it is significant that prior to Bums’ trial the trial judge had found him incompetent to stand trial, and that only after approximately four months of inpatient care had the trial judge found that Bums’ competency had been restored. However, Dr. William J. Stejskal, a court-appointed mental health expert, had opined in his report to the trial court that Bums’ capacity to assist in his own defense was only “marginally intact,” and that Bums would require appropriate antidepressant and anxiety medication under “continuing psychiatric care with respect to the management of the medications.” Bums was receiving these medications, prescribed by a physician, while in jail so that his capacity to assist in his own defense could be maintained. Nevertheless, on the first day of trial it became necessary for the trial court to recess so that medication could be administered to Bums. Then on the next day of trial, Bums became “visibly upset” while a tape of his statement to police was played for the jury. Again the trial court recessed, questioned Bums, and heard evidence from the jail nurse that Bums was receiving the prescribed medications.
During the trial judge’s questioning of Bums, he gave answers that the court reporter noted in some instances as “inaudible” and in others as “unintelligible.” As indicated in the majority opinion, the trial judge dismissed this distinction in Bums’ answers, finding that *348Bums’ “responses were inaudible, not necessarily nonsensical. The bits and pieces that I could understand were responsive to my questions. All told, though, they were simply inaudible.” In contrast to this conclusion, admittedly based on only “bits and pieces” that could be understood, Bums’ counsel asserted that “quite clearly, [Bums] is not thinking rationally at this time, and his statements are incomprehensible. I am sitting right next to him.”
In denying the motion for a competency evaluation, the trial judge expressed in detail his reasons for doing so. Those reasons are related in the majority opinion and need not be repeated here. It is apparent that the trial judge concluded that because Bums was receiving medication he was competent, that he was probably “malingering” or “acting,” and that playing the tape of his statement to the police was understandably “upsetting” to him. In short, the trial judge simply did not believe that Bums lacked substantial capacity to assist his attorney in his own defense. The trial judge may have been right in his conclusions regarding Bums’ competency. No appellate court will ever know for sure, however.
In any event, the trial judge was not called upon under the proper application of Code § 19.2-169.1(A) to determine Bums’ competency or to deny the requested evaluation upon a subjective belief that Bums was “acting” incompetent. Rather, the trial judge was called upon to determine objectively whether from the undisputed facts there existed probable cause to believe that Bums lacked the requisite capacity to assist his attorney in his own defense. Upon a showing of that probable cause, the trial judge was statutorily mandated to order the requested competency evaluation.
In my view, the conclusion that such probable cause was established is compelled by the undisputed facts in this case. Bums was known to be only “marginally” competent to stand trial when the trial began. His competency during trial depended entirely on the continuing effectiveness of the prescribed medications and not merely that Bums received them. On at least one occasion it became necessary to recess the trial proceedings so that Bums could be given additional medication. On another occasion, Bums became “visibly upset,” another recess was required, and at that time he gave “unintelligible” answers to some of the trial judge’s questions. Moreover, Bums’ counsel advised the trial court that Bums was not thinking “rationally” and that Bums’ statements were “incomprehensible” to him. Surely, these circumstances created a reasonable question whether the prescribed medications were continuing to be *349effective so that Bums could maintain substantial capacity to assist his attorney in his own defense. Accordingly, probable cause was established on the issue of Bums’ competency and it was error for the trial court to deny the motion for a competency evaluation as mandated by Code § 19.2-196.1(A).
For these reasons and because the error in this case denied Bums his right to a fair trial, I would reverse his conviction and remand this case for a new trial.