¶1On January 22, 1992, a Superior Court jury found the defendant guilty of murder in the second degree and of carrying an unlicensed firearm. On appeal, we focus on the defendant’s claim that remarks made by one of the jurors were prejudicial.
¶2*770On May 16, 1991, Ronald Taylor was shot at close range on Dakota Street in the Dorchester section of Boston. He died shortly thereafter. The defendant was charged with first degree murder. At trial, defense counsel attempted to demonstrate that none of the Commonwealth’s witnesses had been able to identify the defendant as the assailant with any degree of certainty. Each, for example, had given inconsistent or somewhat vague descriptions of the assailant’s height, clothing, or complexion. Several had initially failed to pick the defendant out from a photographic array. The primary defense, thus, was misidentification. Defense counsel also offered an alternate theory of the case (although not until well into trial) that one Eric Brown, who was alleged to have shot the victim in February, 1991, from a vehicle may have been the perpetrator. The defendant’s only witness, a licensed private investigator, posited that Brown lived near Dakota Street where the shooting took place, in the same direction from the point of shooting in which the assailant reportedly fled after the shooting, and that a vehicle fitting the description of the one in the earlier shooting had been found at Brown’s supposed address.
¶3For its part, the Commonwealth repeatedly tried to establish a gang connection to, or motivation for, the shooting. It attempted to do this by showing (1) that the victim was afraid of gangs in the area (specifically the Vamp Hill Kings) and (2) that the defendant was a member of or frequently “hung with” gangs. With few exceptions, the defendant’s objections to that line of questioning were sustained. Nevertheless, the assistant district attorney returned time and again to that theme with each witness.
¶4Following the first day of jury deliberations, the jury foreman informed the court of possible misconduct by one of the *771jurors, who had related certain extraneous information about the defendant to her fellow jurors.
¶5We are convinced that the juror’s remarks — particularly those concerning the defendant’s possible gang membership — poisoned the jury’s deliberations. The judge had been at some pains to preclude the Commonwealth during its closing from mentioning the words “gang” or “group” and had specifically instructed the jurors to disregard and purge from their minds any reference to gangs or to the defendant’s possible affiliations with gangs.
¶6The central problem here is the jury’s exposure to extraneous matters that were highly prejudicial to the defendant.
¶7Drawing upon established precedent, the Fidler court held that, once questions are raised about jury exposure to extraneous matters, the judge may query individual jurors to determine whether such matters have in fact found their way into the jury room; but the judge shall not inquire what, if any, influence they may have had on the jury’s deliberation process. See id. at 196, citing Woodward v. Leavitt, 107 Mass. 453, 466 (1871); Harrington v. Worcester, Leicester & Spencer St. Ry., 157 Mass. 579, 581-583 (1893); Mattox v. United States, 146 U.S. 140 (1892). If the judge finds that extraneous facts have penetrated the jury’s deliberations, the judge “must focus on the probable effect of the extraneous facts on a hypothetical average jury.” Fidler, supra at 201. Cutler v. Cuffie, 414 Mass. 632, 637 (1993).
¶8That is not the process that was followed here. In his voir dire of jurors, the judge determined that the juror had imparted certain knowledge she had about the defendant and about his possible affiliation with gangs. Then he asked each juror whether he or she could still judge the case solely on the evidence and not on the extraneous information. In so doing, he committed error. See Woodward v. Leavitt, 107 Mass. at 466; Commonwealth v. Fidler, 377 Mass. at 201; Fitzpatrick v. Allen, 410 Mass. 791, 795-796 (1991) (“There can be no inquiry concerning the actual impact of extraneous matter on the jury” [emphasis supplied]).
¶9Upon determining that highly prejudicial extraneous information concerning the defendant had seeped into the jury room, we think the remedy of a new trial was required — whether the judge applied the test in Commonwealth v. Fidler requiring the Commonwealth to show beyond reasonable doubt that the extraneous matter would not have prejudiced the defendant before a “hypothetical average jury,” 377 Mass. at 201; or held instead that, given the nature of that information, the sitting jury could not “fairly be *773modeled by a ‘hypothetical average jury.’ ” Markee v. Biasetti, 410 Mass. 785, 789 (1991).
¶10Throughout the trial, defense counsel scrupulously attempted to avoid and have excluded all testimony concerning “gangs” or “groups.” Over repeated (and sustained) objections, the assistant district attorney continued his efforts to develop the theme.
¶11The judgments are reversed, and the verdicts are set aside.
¶12 So ordered.
¶13Other arguments made by the defendant are either without merit or are unlikely to arise at any retrial. Specifically, the argument seeking suppression of photographic identifications and subsequent in-court identifications is more properly directed to the weight of the evidence and not its admissibility.
¶14See note 7, below.
¶15According to the jury foreman’s testimony during individual voir dire, the juror had remarked that she knew of the defendant and that the defendant was a friend of another individual, Eric Brown, who the defense alleged had shot the murder victim several months prior to the murder and who was also possibly the person who committed the murder. The juror further remarked that Brown had dated her niece and had fathered a child by the niece. The jury foreman claimed the juror also said that the defendant and Brown were members of the same gang and that “she was afraid to walk up the street” because of gangs.
¶16We are not in this case dealing with the dismissal of a juror for personal reasons or “for other good cause” unconnected to the case under G. L. c. 234, § 26B. See Commonwealth v. Connor, 392 Mass. 838, 844-845 (1984).
¶17See, e.g., Markee v. Biasetti, 410 Mass. 785 (1991); Fitzpatrick v. Allen, 410 Mass. 791 (1991).
¶18The judge obviously sensed the gravity of the situation. He remarked at one point to counsel, “I think the case is over. I don’t think there is anything I can do to save this case, frankly.”
¶19Given that actual proof of a gang connection was never established, the latitude allowed the assistant district attorney in this regard should be significantly narrower at any retrial. See Commonwealth v. Wolcott, 28 Mass. App. Ct. 200, 209-210 (1990).