dissenting:
This' case certainly demonstrates “[M]an’s ability to complicate simplicity.”1 The sole issue here is whether the trial court erred in denying, without a hearing, appellant’s motion for a new trial which attacked his conviction as an “aider and abettor” of murder. The trial court justified its holding (that a sworn affidavit of a since-convicted killer (one Allen) did not justify a new trial for the “aider and abettor”) since it (1) supplied only impeaching evidence, and (2) would not likely have produced an acquittal.
On this appeal, I agree with Judge Terry that the statement made by the convicted killer was “newly discovered evidence,” and that the trial court erred in holding that the affidavit was merely “impeaching evidence” (and therefore insufficient to justify a new trial). That leaves us with a still more limited issue, i.e., whether the trial court could accurately predict the outcome of a new jury trial. Therefore, since I likewise agree with Judge Terry that each case must be judged on its own particular facts (citing Byers v. United States, 649 A.2d 279, 287 (D.C.1994)), I would turn to the facts reviewed at length by this court in appellant’s direct appeal. Prophet v. United States, 602 A.2d 1087 (D.C.1992) (Prophet I). Those facts, measured by the opinion’s carefully defined law of the theory of “aiding and abetting,” lead me to believe that the trial court could hardly prophesy the outcome of this ease if this “newly discovered evidence” was found to be credible enough to go before a new jury.
In Prophet I, we summed up broadly — yet succinctly — the horrendous consequences that may be at risk when one is found to be on the scene when a crime (this one murder) is committed. In order to be convicted of that murder, we said, an accused must in some way associate himself with the venture, must participate in it as if wishing to bring it about, and must seek by his action to make it succeed. Id. at 1092. In so holding, we were following the reasoning of countless cases that have described an aider and abettor as one who “assists,” “participates,” “encourages,” “facilitates,” and “stimulates others,” with guilty knowledge, in the commission of the crime. See generally D.C.Code Index 22 (1997 Repl.). Mere presence at the scene of a crime, even when coupled with guilty knowledge, is not sufficient to constitute aiding and abetting. See United States v. Lumpkin, 145 U.S.App. D.C. 162, 448 F.2d 1085 (1971).
There must be presence plus conduct on the part of the aider and abettor. Id. at 167, 448 F.2d at 1090. The question of sufficiency is one for the jury. Ellis v. United States, 395 A.2d 404 (D.C.1978), cert. denied, 442 U.S. 913, 99 S.Ct. 2830, 61 L.Ed.2d 280 (1979).
In affirming this conviction in Prophet I, perhaps the pivotal factor was whether appellant gave an affirmative response when asked by the killer (one Allen) if he wanted the “boom box” of the deceased, as testified to at trial by another young man (one Humes) on the street scene. Despite the fact that a police officer, called by the defense, testified that Humes, when questioned, said nothing about appellant wanting the ra*781dio, the trial court, over strenuous objection by the defense, allowed the government to rehabilitate Humes.2
Against this backdrop, the affidavit of Allen, which my colleagues concede constitutes newly discovered evidence, repudiates the trial testimony of Humes that appellant answered, “Yeah” to any inquiry about wanting the victim’s “boom box.” It avers that the affiant was alone when he shot the victim, and that in no way did Rodney Prophet encourage or influence the action of the affi-ant. While this affidavit, under the circumstances, apparently triggered some skepticism on the part of the experienced trial court, credibility is the determinative issue, and a trial court cannot determine credibility (of an affiant he has not heard) without a hearing to assess this issue. See Newman v. United States, 705 A.2d 246 (D.C.1997).
Here the trial court ruled that it “is inconceivable that Allen’s testimony would lead to an acquittal (of Prophet) after a new trial.” This is little more than a guess — an admittedly “educated guess” — but one based upon considerations not germane to the factual context of this case.3
A wise man once said that “Time” is “what we want most, but what we use worst.” 4 In failing to conduct a short hearing, the trial judge was not saving time. Likewise, in affirming the trial court’s denial (without a hearing) of a motion for a new trial, we are balancing time at the expense of more important considerations. I would remand for a hearing.
. Thor Heyerdahl, quoted in Webster’s New World Dictionary of Quotable Definitions by Eugene E. Brussell (2d ed.1988), as an example of “Progress," at 457.
. As to the allegation that appellant acted as a lookout for the killer — stricken—(but a factor from which the jury was permitted to draw an inference from testimony that appellant met with Allen after the murder) I note that the evidence showed that appellant was standing with others some 264 feet from the shooting site.
. Counsel for appellant, citing case law and rules of evidence, has forcefully advanced the difficulties which the prosecution would face in attempting to impeach the affiant at any subsequent trial under the circumstances of this case.
. William Penn, quoted in Webster’s New World Dictionary of Quotable Definitions, supra note 1, at 570.