delivered the opinion of the court.
The first question to be determined (and which is the subject of the first, second, and fourth bills of exception) relates -to the competency as witnesses of John Williams and Preston Matheny, the alleged principals in the felony charged in the indictment, and aged, respectively, nine and fourteen years. At the trial they were called and testified for the commonwealth. Their competency is denied by the plaintiff in error, on the ground of their confessed guilt of the felony charged, and because of their *592want of understanding of the nature and moral obligation of an oath.
In support of the first objection, counsel rely, in part, on the statute, which provides that, “approvers shall not be admitted in any case.” Code 1813, chapter one hundred and ninety-five, section eighteen. But no such question arises in the present case. The English doctrines relating to the admission of approvers seem never to have become incorporated into the laws of this state, and the ancient practice in England, which was confined to capital cases, has been long disused. 4 Bl. Comm. 330; 1 Bishop on Crim. Procedure, sec. 1012, et seq.; Dabney’s Case, 1 Rob. Rep. 696. Ordinarily, an accomplice is a competent witness on the trial of his associate, provided he has not been previously sentenced and convicted of an infamous offence, which is not the case here. And by statute in Virginia his incompetency by reason of interest has been removed, unless jointly tried with his associate. Code 1813, chapter one hundred and ninety-five, section twenty-one.
It is an equally well settled rule of evidence that an infant under fourteen may be examined as a witness, provided he sufficiently appears to understand the nature and moral obligation of an oath; for competency depends not upon age but understanding. At the age of fourteen, every person is presumed to have common discretion and the necessary understanding of the obligation of an oatb, until the contrary appears; but under that age it is not so presumed.
In this case, without stopping to review the evidence, it is sufficient to say that the competency of the witness Williams is satisfactorily established, and that sufficient evidence does not appear in the record to establish the incompetency of the witness Matheny. The testimony of both was, therefore, properly admitted by the county court.
The third bill of exceptions raises the question, whether a witness, whose competency has been affirmed by the court, may be examined before the jury touching his understanding of the *593obligation of an oath. The county court held such examination to be inadmissible, and we think correctly. It is for the court to determine what is evidence, and for the jury to weigh it; and the court having once decided in favor of the competency of a witness, the decision cannot be indirectly reopened by raising questions before the jury, which, in effect, go to the competency of the witness. In the present case, the avowed object in the course of examination sought to be pursued, was to affect, not the competency, but the credibility, of the witness; but the questions propounded relate properly to his competency and not to his credibility, and were, therefore, rightly excluded.
The next question arises upon the fifth bill of exceptions, which was taken to the action of the court in admitting, against the objection of the prisoner, the testimony of the witness Richardson. The witness testified that he had frequently seen the boy, Williams, about the prisoner’s place of business, which was in the neighborhood of the depot; that he had seen him there about ten days before the depot was burned, and near there on the day it was burned. The obvious object of the attorney for the commonwealth in calling the witness was to show the connection and relations existing between the prisoner and Williams, and in that view the testimony of the witness was admissible evidence to go to the jury.
The subject of the sixth bill of exceptions is the action of the court in admitting the testimony of the witness Pendleton. The witness was a police officer, who testified that when he arrested Williams in Lynchburg, soon after the depot was burned, the latter, confessed to him that the prisoner had employed him (Williams) and Preston Matheny to burn the depot, and that they did so. The prisoner objected to the introduction of this testimony, but the objection was overruled and the testimony admitted. In so doing we think the court plainly erred. The testimony was, doubtless, introduced for the purpose of corroborating the accomplice, Williams, by showing that he had previously made statements out of court similar to those made by him as a witness *594in the case. But the testimony was merely heresay, and therefore inadmissible, even though a previous conspiracy and combination had been proved between the prisoner and Williams; his statements having been made after the commission of the offence and after the object of the conspiracy had been accomplished. Hunter’s Case, 7 Gratt. 641; Hayne’s Case, 28 Gratt. 942; Jones’s Case, 31 Gratt. 836.
The testimony being thus illegal and calculated to prejudice the prisoner, the judgment must be reversed. It is well settled in Virginia that a judgment will not be reversed for the admission of improper testimony when it is plain that its introduction could not possibly have prejudiced the defendant. But if he may have been so prejudiced, even though it be doubtful whether in fact he was so or not, that is sufficient ground for reversing the judgment. Payne’s Case, 31 Gratt. 855, and cases cited.
The questions raised by the seventh bill of exceptions were waived by the counsel for the prisoner; and those raised by the eighth and last, respecting the sufficiency of the evidence to ■support the verdict, need not be considered; as for the error indicated the judgment must be reversed and a new trial awarded.
The order is as follows:
This day came again, as well the attorney-general, on behalf of the commonwealth, as the plaintiff in error by his counsel, and the court having maturely considered the transcript of the record of the judgment aforesaid and the argument of. counsel, is of opinion, for reasons stated in writing and filed with the record, that the said judgment of the circuit court, affirming the judgment of the county court of Bedford county, is erroneous, in that the said county court erred in not excluding from the jury as evidence on the trial of the issue joined in this case the testimony of the witness, J. D. Pendleton, set out in the sixth bill of exceptions in the record, in response to the questions of the attorney for the commonwealth also set out in said bill. It is, *595therefore, considered and ordered that for the error aforesaid, the said judgment of the circuit court he reversed and annulled. And this court now proceeding to enter such order as the said circuit court ought to have entered, it is further ordered, that the said judgment of the said county court he reversed and annulled, the verdict of the jury set aside, and that this case he remanded to the said county court for a new trial of the issue joined. Which is ordered to he certified to the said county court.
Judgment reversed.