On November 8, 1981, the body of a young woman was found, strangled to death, in a wooded area of *441Middleborough. The defendant, Paul S. Reed, stands convicted of murder in the first degree for the victim’s death. Critical to the Commonwealth’s case was the evidence provided by one Patton Flannery, an inmate at the Massachusetts Correctional Institution at Bridgewater. Flannery said that the defendant admitted to him that he had killed the victim. At the Commonwealth’s urging and over the defendant’s timely objection, the judge admitted testimony from Flannery that he (Flannery) had a conversation with the defendant’s wife, in the defendant’s absence. In that conversation, the defendant’s wife told Flannery that the defendant had told her that he (the defendant) had committed the crime. The judge admitted this hearsay evidence as an adoptive admission and in his instructions told the jurors that they could consider the evidence of this conversation as “corroborative evidence.” There is no dispute that the judge’s ruling is erroneous. At issue is whether the admission of that evidence was prejudicial error. We conclude that the error is prejudicial. Consequently, we reverse and remand for a new trial.

Apart from Flannery’s testimony that the defendant admitted to him that he was the culprit, there was evidence that on November 8, 1981, the defendant’s wife reported the theft of her automobile to the Bridgewater police. The police recovered the vehicle from an area in Plympton where the defendant frequently went to pick grapes and blueberries. The vehicle had been burned. A State police chemist found traces of rabbit hair in the automobile which were similar to the hairs from a rabbit fur coat worn by the victim and found near her body.

1. The Conversation as an Adoptive Admission. On Monday, November 9, 1981, the defendant’s wife visited Flannery at M.C.I., Bridgewater.1 According to Flannery, the defendant’s wife said that the defendant told her that he had slain the victim on Saturday, November 7. On Saturday, November 14, 1981, the defendant visited Flannery. Again according to Flannery, and at Flannery’s prompting,2 the defendant told him the *442details of the homicide. In his instructions, the judge told the jury that the evidence of the wife’s conversation with Flannery was admitted under the adoptive admission exception to the hearsay rule for the purpose of corroborating the admissions made by the defendant to Flannery. The admission of the conversation between Flannery and the defendant’s wife was error.

An adoptive admission is “a statement . . . made in the hearing of another, in regard to facts affecting his rights, and [that person’s] reply, wholly or partially admitting their truth.” Commonwealth v. Kenney, 12 Met. 235, 237 (1847). The declaration and the reply are admissible, as an exception to the hearsay rule, because “the reply ... is the act of the party, who will not be presumed to admit any thing affecting his own interest, or his own rights, unless compelled to it by the force of truth; and the declaration . . . give[s] meaning and effect to the reply” (emphasis in original). Id. See Commonwealth v. Earltop, 372 Mass. 199, 201-202 (1977); Commonwealth v. Sazama, 339 Mass. 154, 156-157 (1959); Commonwealth v. Boris, 317 Mass. 309, 317 (1944); P.J. Liacos, Massachusetts Evidence, 287-289 (5th ed. 1981).

Because the defendant was not present at the conversation between his wife and Flannery, there was no adoptive admission. The evidence was hearsay not within an exception and therefore should pot have been admitted. We turn to the question whether the admission of this evidence was prejudicial.

Flannery testified that the defendant made admissions to him; the defendant denied the conversation took place. Thus, the jurors were faced with a classic duel of credibility. The Commonwealth’s evidence apart from Flannery’s testimony was not decisive of the defendant’s guilt, but merely corroborated bits and pieces of Flannery’s testimony, or attempted to establish Flannery’s reputation for truth and veracity in his community (M.C.I., Bridgewater). A witness for the defendant asserted that he was with Flannery and the defendant on November 14, 1981, and that they did not have a private conversation. Defense witnesses also testified differently from *443the Commonwealth’s witnesses as to Flannery’s reputation for truth and veracity. In these circumstances, testimony by Flannery of a private conversation between the defendant and his wife may have had a decisive bearing on the verdict. Further, the prosecutor, on redirect, had Flannery identify the defendant’s wife in the courtroom, thus, perhaps, encouraging the jurors to draw a negative inference from her failure to testify.3

In his summation, the prosecutor argued that Flannery’s credibility was the critical issue. He reminded the jury that the defendant’s wife was the first person to take Flannery “into their confidence about the facts of this murder.” The prosecutor then said that, because of the conversation between Flannery and the defendant’s wife, the defendant had no choice but to take Flannery into his confidence. We cannot say that the evidence and the prosecutor’s argument did not have the effect the Commonwealth intended it to have.

Nor can we say “with fair assurance,” that the jury did not attach substantial significance to evidence of a private conversation between husband and wife or that such evidence did not have a substantial impact on the issue of Flannery’s credibility. We conclude that the defendant has shown that “the error possibly weakened his case in some significant way.” Commonwealth v. Schulze, 389 Mass. 735, 741 (1983).4

*4442. Other Issues Likely to Recur at a New Trial.

a. Evidence of prior convictions. The defendant filed a motion in limine which sought to bar the introduction of the defendant’s prior criminal record for purposes of impeachment. The defendant argues that the admission in evidence of prior convictions gave rise to unfair prejudice which outweighed the probative value of that evidence for impeachment purposes. See Commonwealth v.' Maguire, 392 Mass. 466, 470 (1984). This case, however, was tried before the Maguire opinion was issued. Because we conclude that the defendant is entitled to a new trial on other grounds, we need not decide whether the admission of the defendant’s prior convictions constituted an abuse of discretion.5

b. Testimony of James Lawson. James Lawson, a Bridge-water inmate, testified to a telephone call to the defendant’s wife. The defendant was in the same room as his wife but neither affirmed nor denied the conversation. Again, on the record before us there is no evidence that the defendant heard the conversation or that he was in a position to make a reply. This conversation is not admissible. See supra at 442. “We are not inclined to extend the scope of the doctrine of admission by silence.” Leone v. Doran, 363 Mass. 1, 16 (1973).6

*445The judgment is reversed, the verdict set aside and the case remanded to the Superior Court for a new trial.

So ordered.

(dissenting, with whom Nolan, J., joins). I respectfully dissent. I agree that Flannery’s testimony regarding statements by Nancy Reed should not have been admitted. Although that testimony should have been excluded, I believe that no prejudice resulted. This is so because the defendant testified and denied that he ever made either statement. If the jury were willing to believe that the defendant himself confessed to Flannery, then that was enough evidence. If they chose to disbelieve Flannery’s testimony on that point, then surely they would have rejected Flannery’s testimony regarding the statements of Nancy Reed. As Judge Learned Hand put it, “[i]f, from all that the jury see of the witness, they conclude that what he says now is not the truth, but what he said before, they are none the less deciding from what they see and hear of that person and in court.” DiCarlo v. United States, 6 F.2d 364, 368 (2d Cir.), cert. denied, 268 U.S. 706 (1925). As such, the evidence of Nancy Reed’s statements could only be cumulative and not prejudicial. See Commonwealth v. Lowe, 391 Mass. 97, 106, cert. denied, 105 S.Ct. 143 (1984); Commonwealth v. Bongarzone, 390 Mass. 326, 342 (1983).

My opinion in this regard is fortified by the fact that the judge limited the use of this testimony to corroboration of the defendant’s own admissions to Flannery. Thus the statements properly could not have been considered as proof of the matter asserted. In this limited form the evidence pales into insignificance in the face of Flannery’s statement that the defendant admitted the crime and the defendant’s testimony that he did not.

*446In regard to the admission of the evidence of the defendant’s prior convictions, I wish to emphasize that I do not depart from the view I expressed in my concurrence in Commonwealth v. Elliot, 393 Mass. 824, 834 (1985): “Evidence of a prior conviction, especially of a violent crime or one involving dishonesty, is probative as to the defendant’s credibility as a witness. See Advisory Committee Note to First Draft of Proposed Fed. R. Evid. 609(a), reprinted in 46 F.R.D. 161, 297 (1969) (‘A demonstrated instance of willingness to engage in conduct in disregard of accepted patterns is translatable into willingness to give false testimony’). A reasonable basis exists, therefore, for the legislative determination that evidence that the defendant has been found guilty of a failure to conform his conduct to the legal norms of society should be brought to the jury’s attention, as an aid in evaluating the defendant’s sincerity and reliability as a witness. The judge’s role should generally be limited to preventing misuse of the evidence, through appropriate limiting instructions and careful monitoring of the prosecutor’s use of the evidence at trial. Only in extreme circumstances, not shown to be present here, would I conclude that the danger of unfair prejudice required the exclusion of such evidence” (emphasis in original). Id. at 835 (Lynch, J., concurring).