A jury convicted Lorenzo McLean of robbery and of capital murder for a killing committed in the commission of a robbery. On this appeal, McLean contends the trial judge erred by instructing the jury during their deliberations on “concert *596of action” in response to the jury’s questions about “intent.” For the reasons that follow, we reverse the convictions and remand for a new trial.
I.
The evidence at trial proved that a police officer found the unconscious and severely beaten body of William Jones, Jr. in a park in the City of Norfolk on January 1,1995. Near Jones’ body, the police found a bloodstained concrete splash block. Jones later died. An autopsy revealed that Jones had received extensive blunt force trauma to his head, chest, and other areas of his body. Jones also had an incision in his neck which cut his jugular vein and a single stab wound to his chest. The assistant medical examiner testified that several of the injuries suffered by Jones would have been sufficient alone to eventually cause Jones’ death.
Nathaniel Lindsey testified that he, Lorenzo McLean, Neil Bates, and another man known as “Skip” were drinking alcoholic beverages and smoking marijuana in the park at night when they encountered Jones, who was drinking beer in the park. After the men talked with Jones, they pooled their money with Jones in an unsuccessful attempt to buy more alcoholic beverages.
Lindsey testified that McLean accused Jones of being homosexual and called Jones a “fag” several times. Jones responded to McLean’s taunts by attempting to hit McLean. When Jones missed, McLean and Bates each struck Jones with their fists, causing Jones to fall. Lindsey then kicked Jones twice. McLean and Skip continued the assault by throwing a bicycle on Jones. After McLean stated that Jones had seen their faces, McLean said, “we got to kill him.” McLean then asked if anyone had a weapon.
According to Lindsey’s testimony, Lindsey and Bates grabbed a concrete splash block near a building. Lindsey testified, however, that he dropped the splash block and walked away because he “didn’t feel right” about dropping it on Jones. Lindsey testified that when he turned the corner of *597a building he met a woman and smoked a cigarette with her. During the ten minutes he was smoking the cigarette, he heard no noise from the park. Lindsey testified that he then returned to the park and saw Bates and Skip drop the splash block on Jones’ head. Bates and McLean then dropped the splash block on Jones’ head.
Lindsey further testified that McLean and Skip discussed whether Jones had money. Lindsey saw Skip put his hands in Jones’ pockets and throw Jones’ wallet and identification in a field behind the park. He testified that he saw no one take money from Jones. Lindsey said McLean then broke a bottle and stuck it in Jones’ neck. Lindsey testified that after he, McLean, Bates, and Skip left the park, McLean changed his shoes because they were covered with blood.
Sharee McCorkle testified that on that same night she heard noise coming from the park. She heard a man saying, “come on, man, help me,” and heard McLean, whom she had known “a long time,” respond, “I can’t help you.” McCorkle testified that, although the park was unlit, she saw five or six people in the park and saw McLean as he slammed the cement block on Jones’ face.
Keisha Sanderson testified that when she saw McLean that night, he had blood on his tennis shoes and had food stamps. When she later saw McLean, he had changed clothes.
During the presentation of his evidence, McLean testified that he could not remember where he was on January 1,1995. He also testified that he had never met Jones, that he was not in the park the night Jones was küled, and that the Commonwealth’s witnesses were “out to get him.”
After the trial judge instructed the jury at the conclusion of the evidence, the jury sent two written questions to the judge during their deliberations. They asked: “May we have a legal definition of intent?” and “Is the word intent collective?” The trial judge told the prosecutor and McLean’s counsel that he would not answer the first question. The trial judge then asked the jury to state “what they mean by that [second] question.” The jury restated the question as follows: “Once *598the intent is spoken by one member of a group and the act is performed, does the intent to commit the act apply to all? What is the law concerning this?” Over McLean’s counsel’s objection, the trial judge responded by informing the jury according to the following instruction offered by the Commonwealth:
If you find that there is a concert of action with the resulting crime one of its incidental, probable consequences, then whether such crime was originally contemplated or not, all who participate in any way in bringing it about are equally answerable and bound by the acts of every other person connected with the consummation of the resulting crime.
The jury convicted McLean of capital murder and robbery and recommended a sentence of life in prison on the capital murder conviction. The trial judge imposed that sentence. Because McLean was a juvenile at the time of the robbery offense, the trial judge determined McLean’s sentence for robbery and imposed a life sentence.
II.
Rule 3A:16(a) provides that “[i]n all cases the court shall instruct the jury before arguments of counsel to the jury.” The principle is also well established that “[i]t [is] ... proper for the [trial judge] to fully and completely respond to inquiry which might come from the jury for information touching their duties.” Williams v. Commonwealth, 85 Va. 607, 609, 8 S.E. 470, 471 (1889). See also Marlowe v. Commonwealth, 2 Va.App. 619, 625, 347 S.E.2d 167, 171 (1986). “The trial judge’s ‘imperative duty [to properly instruct the jury] ... is one which can be neither evaded nor surrendered.’ ” Johnson v. Commonwealth, 20 Va.App. 547, 554, 458 S.E.2d 599, 602 (1995) (citation omitted). Thus, when read together, Rule 3A:16(a) and Virginia case decisions allow the trial judge to give a supplemental jury instruction which clarifies an existing instruction or a principle previously existing before the jury.
*599The jury’s questions clearly indicate that the jury was seeking a definition of intent, an issue in the case. At the conclusion of the evidence, the trial judge had given the jury the following instructions concerning intent:
The defendant is charged with the crime of capital murder. The Commonwealth must prove beyond a reasonable doubt each of the following elements of that crime:
(1) That the defendant killed William Jones; and
(2) That the killing was willful, deliberate and premeditated; and
(3) That the killing occurred during the commission of a robbery while the defendant was armed with a deadly weapon.
‘Willful, deliberate, and premeditated” means a specific intent to kill, adopted at some time before the killing, but which need not exist for any particular length of time.
The defendant is charged with the crime of robbery of William Jones. The Commonwealth must prove beyond a reasonable doubt each of the following elements of that crime:
(1) That the defendant intended to steal; and
(2) That property was taken; and
(3) That the taking was from William Jones or in his presence; and
(4) That the taking was against the will of the owner or possessor; and
(5) That the taking was accomplished by beating William Jones.
The principal elements of robbery, a crime against the person of the victim, are the taking, the intent to steal and violence. The violence must occur before or at the time of the taking. The intent to steal and taking must co-exist. *600The offense is not robbery unless the intent was conceived before or at the time the violence was committed.
# * * * * *
You may infer that every person intends the natural and probable consequences of his acts.
(Emphasis added).
When the jury asked the questions, “May we have a legal definition of intent?” and “Is the word intent collective?,” the trial judge did not answer the first question and asked the jury to state “what they mean by that [second] question.” The jury then asked, “Once the intent is spoken by one member of a group and the act is performed, does the intent to commit the act apply to all? What is the law concerning this?” In response to these inquiries, the trial judge interjected for the first time the issue of “concert of action.” “However, if a supplemental jury instruction given in response to a jury’s question introduces a new theory to the case, the parties should be given an opportunity to argue the new theory.” United States v. Fontenot, 14 F.3d 1364, 1368 (9th Cir.), cert. denied, 513 U.S. 966, 115 S.Ct. 431, 130 L.Ed.2d 343 (1994). Failure to allow argument after a new issue is introduced in the case results in “unfair prejudice.” Id. See also Bouknight v. United States, 641 A.2d 857, 861 (D.C.1994) (after giving a supplemental instruction on aiding and abetting, a new theory of liability, the trial judge properly allowed limited additional argument).
None of the jury instructions had mentioned “concert of action” or touched upon that principle as a theory of liability. Thus, this is not a case in which the trial judge amended an instruction that was erroneous when earlier given to the jury. See Blevins v. Commonwealth, 209 Va. 622, 628, 166 S.E.2d 325, 330 (1969) (stating that the trial judge “not only has the right but ... a duty to amend instructions which appear to be erroneous or misleading after summation by counsel”). The jury had not been instructed on the concept of “concert of action,” and the jury made no inquiry about that concept. By injecting in the trial for the first time during jury *601deliberations the concept of “concert of action,” the trial judge deprived McLean of the right to have his counsel argue to the jury the principles contained in the instruction as they related to the facts of the case. See Rule 3A:16(a).
In addition, when responding to the jury’s inquiry concerning their duties, the trial judge must fully and accurately inform the jury on matters upon which the jury makes inquiry. See Jones v. Commonwealth, 194 Va. 273, 278, 72 S.E.2d 693, 696 (1952). The supplemental instruction that the trial judge gave to the jury falls short of this standard. Even if the trial judge’s response to the jury’s inquiry correctly stated the law of “concert of action,” the trial judge erred by answering the jury in a manner that was incomplete and nonresponsive to the jury’s inquiry. See Shepperson v. Commonwealth, 19 Va.App. 586, 591-92, 454 S.E.2d 5, 8 (1995). Simply put, “the statement by the [trial judge] in the case in judgment did not fully inform the jury upon the point to which their inquiry was directed.” Jones, 194 Va. at 278, 72 S.E.2d at 696.
The failure to respond to the jury’s inquiry concerning intent and the giving of an instruction on “concert of action,” without directly responding to the jury’s inquiry, “might have had the effect to mislead the jury as to the law of the case.” Wren v. Commonwealth, 66 Va. (25 Gratt.) 989, 994 (1875). Indeed, as the Supreme Court observed in Wren, “[t]he jury, composed of ... [people] without knowledge of legal principles, might have been led to believe [another proposition from the trial judge’s nonresponsive answer].” Id. at 995. The jury certainly could have concluded that the question of intent, on which they sought further guidance, was not as germane to their inquiry as was the principle of “concert of action,” which the trial judge injected at the request of the Commonwealth.
For these reasons, we reverse the convictions and remand for a new trial.
Reversed and remanded.