The defendant was convicted by a Superior Court jury of armed home invasion and receiving stolen property (a motor vehicle). On an indictment charging the defendant with breaking and entering in the daytime, with intent to commit a felony, the jury convicted the defendant of the lesser included offense of breaking and entering in the daytime with intent to commit a misdemeanor. That conviction was placed on file with the defendant’s consent. The defendant was acquitted of armed robbery and armed assault in a dwelling. In an unpublished memorandum and order pursuant to its rule 1:28, a panel of the Appeals Court affirmed the conviction of receiving stolen property, but reversed the convictions of armed home invasion and breaking and entering, holding that the trial judge abused his discretion in allowing fourteen of the defendant’s prior convictions to be admitted in evidence for impeachment purposes. Commonwealth v. Brown, 68 Mass. App. Ct. 1114 (2007). We granted the Commonwealth’s application for further appellate review, and now affirm all the convictions.
Facts. The defendant and the victim presented sharply differing versions of the incidents in question. According to the victim, the defendant, who was an acquaintance, broke down the door of his apartment and threatened him with a knife, demanding money. The victim testified that, after he gave the defendant all the money he had, the defendant demanded more, but left the apartment after the victim’s roommate appeared. He fled in a stolen automobile and was apprehended shortly thereafter.
The defendant, who admitted to being a drug addict and prostitute, testified that the victim was one of his regular customers, and that the previous night the victim had invited him to the apartment, offering to pay him for sex. The defendant went to the victim’s apartment intending to execute a “hustle” whereby *202he would extract more money from the victim than he would normally have been paid. He succeeded in doing so. The next morning, the defendant returned to the apartment, hoping to shower and have something to eat; the victim was angry at having been hustled and refused to speak with the defendant. The defendant left the apartment but returned when he realized he had left his cellular telephone behind. According to the defendant, the victim refused to let him in, and when the defendant pushed in the door with his shoulder, the victim and his roommate attacked him. The defendant asserted that he had no intention of assaulting or threatening the victim, but wanted only to retrieve his telephone; he said that he pulled out his knife only to defend himself, and that he fled as soon as the victim and his roommate released him.
Discussion. 1. The defendant’s prior convictions. Immediately prior to the start of trial, the prosecutor presented the judge with a list of the defendant’s prior convictions, seeking a ruling as to which would be admissible to impeach the defendant’s credibility should he testify. The judge excluded a number of the convictions (of breaking and entering, receiving stolen property, and larceny of a motor vehicle) because of their similarity to the offenses charged. He approved the admission of fourteen prior convictions, including seven of larceny, four of malicious destruction of property, and one of resisting arrest.1
The Appeals Court reasoned that, while the number of convictions alone did not warrant reversal, the admission of the convictions of resisting arrest and malicious destruction of property in combination might have given the jury the impression that the defendant had a propensity for violence, and that he was the type of person who was capable of breaking down a door and forcing a person to part with his money. This, according to the Appeals Court, was an abuse of discretion that required reversal of the convictions of home invasion and breaking and entering.
We disagree. Pursuant to G. L. c. 233, 21, the prior convic-*203tians of a witness, including the defendant, are admissible for impeachment purposes. Prior convictions may be introduced in the discretion of the judge, who weighs the danger of unfair prejudice that might result from the admission of such evidence against its probative value for impeachment purposes. Commonwealth v. Maguire, 392 Mass. 466, 470 (1984). The admission of a large number of convictions does not by itself create a risk of prejudice sufficient to warrant reversal. See Commonwealth v. Reid, 400 Mass. 534, 539 (1987) (“We have never suggested that an abuse of discretion would arise from the admission of dissimilar prior convictions merely because they are numerous”); Commonwealth v. White, 48 Mass. App. Ct. 658, 661 (2000) (no error to admit twenty-three prior convictions for impeachment: “we are unaware of any authority imposing a numerical limit to such proof”). Indeed, we have noted that “[i]t is at least difficult, if not impossible, to show an abuse of discretion in the absence of a ‘substantial similarity’ between the offenses being tried and the prior convictions.” Commonwealth v. Drumgold, 423 Mass. 230, 250 (1996), quoting Commonwealth v. Preston, 27 Mass. App. Ct. 16, 23 (1989).
The convictions admitted here are not substantially similar to the charged offenses in any way that we have heretofore recognized. Neither the defendant nor the Appeals Court cites any authority for the proposition that two offenses, in themselves dissimilar to a charged crime, may, when combined, create such a risk of prejudice that their admission would be an abuse of discretion. The judge here recognized his discretion and exercised it, excluding convictions of offenses that were substantially similar to the crimes charged. In addition, he gave an appropriate limiting instruction in his final charge, reminding the jury of the restricted purpose for which the evidence could be used.2 Finally, the prosecutor’s brief reference to the defendant’s prior *204convictions in his closing argument merely reminded the jury that they should consider that evidence only for the purpose of assessing the defendant’s credibility. There was no error.3
The defendant’s prior convictions are admissible not because of a common-law rule, but by virtue of a statute, G. L. c. 233, § 21. That statute has been in existence, in one form or another, for over a century. See St. 1852, c. 312, § 60. See also Commonwealth v. Hall, 4 Allen 305, 306-307 (1862). In all that time, the Legislature has never seen fit to limit the number of convictions that may be admitted. We must therefore presume that the Legislature has considered, and rejected, the generalized policy concerns raised by the dissent.
As with the number of convictions, the Legislature has not included a limitation on the type of convictions that can be used for impeachment. The consideration of similarities between the prior convictions and the charged offense is a judicial gloss that this court has placed on the statute. See Commonwealth v. Chase, 372 Mass. 736, 749-751 (1977). We have never considered the effect of prior convictions in combination, and we decline to do so now. The use of the defendant’s prior convictions is consistent with G. L. c. 233, § 21. The only way to avoid application of the statute in this case would be to conclude that the statute is unconstitutional as applied, essentially the unspoken contention of the dissent.4 The defendant has not argued that admission of the convictions violated his constitutional rights, and we will not so conclude today. The dissent’s *205policy judgments are properly a matter for the Legislature, not for this court.
The defendant raises a number of other issues on appeal. In each instance, the Appeals Court found either no error, that any error was harmless, or that no substantial risk of a miscarriage of justice existed. We address these issues in turn.
2. Jury instruction on home invasion. To obtain a conviction of armed home invasion, the Commonwealth must prove that the defendant (1) knowingly entered the dwelling place of another; (2) knowing or having reason to know that one or more persons were present therein, or, having entered without such knowledge, remained in the dwelling place after acquiring or having reason to have acquired such knowledge; (3) while armed with a dangerous weapon; and (4) used force or threatened the imminent use of force upon any person within such dwelling place, whether or not injury occurred, or intentionally caused injury to any person within such dwelling place. G. L. c. 265, § 18C. Commonwealth v. Doucette, 430 Mass. 461, 465-566 (1999). The statute contains no intent requirement for the first prong of the fourth element, the use or threat of force.
In instructing on the fourth element, the judge told the jury,
“The fourth element!,] which the Commonwealth must prove beyond a reasonable doubt!,] is that the defendant used force or threatened the use of force upon any person within the dwelling place. Whether injury occurred from this use of force or threatened use of force is not relevant to your determination. An alternative is that the Commonwealth may prove beyond a reasonable doubt that the defendant intentionally caused an injury to a person within a dwelling place.”
The defendant requested an instruction similar to that recommended by the Appeals Court in Commonwealth v. Cowans, 52 Mass. App. Ct. 811, 821 (2001), requiring as essential for conviction a finding of specific intent to use or threaten the use of force.5 The judge declined to give such an instruction, and the defendant now claims that the omission was error.
In the Cowans case, the Appeals Court reversed a home inva*206sion conviction, holding that it was based on a faulty jury instruction. In that case, the judge instructed the jury that “[t]he mere entry of a house with a weapon in hand is sufficient to trigger the assault aspect” of home invasion. Id. at 817. When the jury sought reinstruction on the elements of home invasion, the judge altered the instruction somewhat, stating that, if the jury found that the defendant entered the house with a weapon, and the person within was put in fear, the fourth element was satisfied; he added that “[t]he threat may be inferred . . . when the person is in [the dwelling] with a dangerous weapon.” Id. at 817-818.
By means of the new formulation instructing that the jury could infer a threat of force merely from the fact that the defendant was in the dwelling and was armed, the judge effectively removed the fourth element from the jury’s consideration. We agree that that was error; however, we believe that the Appeals Court’s suggested instruction goes too far in requiring the jury to find a specific intent to cause fear or apprehension in order to satisfy the first prong of the fourth element. The Legislature could have included a mental state requirement in the first prong; that they did so elsewhere in G. L. c. 265, § 18C (“[w]hoever knowingly enters . . . knowing or having reason to know that one or more persons are present ... or intentionally causes any injury”), suggests that this omission is not accidental. We decline to endorse the language suggested by the Appeals Court in the Cowans decision. The instruction in this case was consistent with both the text of G. L. c. 265, § 18C, and the model jury instructions. See Massachusetts Superior Court Criminal Practice Jury Instructions § 2.31 (Mass. Continuing Legal Educ. 1999 & Supp. 2003). There was no error.
3. Witness’s nonverbal responses. During cross-examination, the victim appears to have had difficulty articulating verbal responses to some of defense counsel’s questions.6 The judge *207interjected: “Occasionally the witness is not answering verbally, but he’s nodding affirmatively or is shaking his head negatively, so I think that under the circumstances, ... the court reporter can note that for purposes of the record that when she sees a nonverbal response that she can record that in the record.” Defense counsel did not object, and the victim proceeded to respond to a large number of defense counsel’s questions by nodding or shaking his head.
The defendant now claims that, because the judge allowed the victim to answer questions nonverbally, the jury were deprived of an opportunity adequately to assess his credibility, and that the defendant’s right of confrontation was thereby violated. Because the defendant did not object, the error, if any, is reviewed for a substantial risk of a miscarriage of justice. See Commonwealth v. Randolph, 438 Mass. 290, 297 (2002).
As a general principle, a jury should be afforded the fullest possible opportunity to observe all aspects of a witness’s demeanor, including both verbal and nonverbal responses, in order to make credibility determinations. See Commonwealth v. Berg-strom, 402 Mass. 534, 548 (1988). Therefore, we are in general agreement with the Appeals Court’s suggestion that the better practice for a trial judge is to require all witnesses capable of providing verbal responses to do so.
Although it is not entirely clear from the record what transpired in this case, we can infer that an experienced trial judge determined that the witness was having difficulty formulating verbal responses to defense counsel’s questions. While additional comment on the problem, or a hearing on the need to allow nonverbal responses, might have been preferable, we cannot say that the judge’s handling of the situation constituted an abuse of discretion. The witness was on the stand for an extended period of time during both direct and cross-examination, and he gave a substantial number of verbal responses in addition to the nonverbal ones. The jury had ample opportunity to observe his demeanor, including his articulation of some of the answers. Furthermore, there was no objection from counsel to alert the judge to any potential problem.
The defendant’s concern is that allowing the victim to answer nonverbally buttressed his credibility by allowing him to evade *208the type of verbal communication that might have made his testimony seem less credible. However, the defendant clearly was able to use the victim’s speaking difficulties to his advantage, first by eliciting from several witnesses that they had never heard him stutter before, and then by suggesting in closing argument that the victim’s stuttering was either feigned or indicative of deceptiveness. That the jury then acquitted the defendant of armed robbery and armed assault in a dwelling, and convicted him of a lesser included offense on the indictment charging breaking and entering with intent to commit a felony, suggests that they did not credit the victim’s testimony, at least with respect to certain evidence. There was no error.
4. Use of the defendant’s silence. Finally, the defendant argues that the trial judge improperly forced defense counsel to comment on the defendant’s failure to make a statement to the police following his arrest. On direct examination, the defendant responded to a question about whether he had been allowed to make a telephone call while in custody by saying, “I was being questioned for several hours.” The answer was nonresponsive; however, neither party objected or asked the judge to strike it.
At the end of the direct examination, the prosecutor requested a sidebar conference. He expressed concern that the defendant’s reply might give the jury the impression that the defendant had told the police he had acted in self-defense when in fact he had refused to answer questions or to make a statement. Urged by the judge to clear up the confusion, defense counsel then asked the defendant if he had given a statement to the police; he replied that he had not. There was no further comment on or reference to this exchange by either party or the judge.7 The defendant now claims that the jury were permitted to infer that he was guilty based on his failure to give a statement to police.
It is, of course, axiomatic that a defendant’s silence after Miranda warnings have been given may not be used to support an inference of guilt. See, e.g., Doyle v. Ohio, 426 U.S. 610, *209617-618 (1976); Commonwealth v. Peixoto, 430 Mass. 654, 658-659 (2000); Commonwealth v. Mahdi, 388 Mass. 679, 694-695 (1983). An exception to this rule exists where comment on the defendant’s invocation of his right to silence serves to avert or alleviate jury confusion about the abrupt termination of a police interview. See Commonwealth v. Martinez, 431 Mass. 168, 183 (2000); Commonwealth v. Thad T., 59 Mass. App. Ct. 497, 502-503 (2003). That exception does not apply here; even if it did, however, the prosecutor waived any objection by failing to assert it when the testimony about police questioning was offered, or when the defendant gave a nonresponsive answer. Cf. Commonwealth v. Foster, 411 Mass. 762, 768-769 (1992) (failure to make timely objection constitutes waiver). Moreover, the Commonwealth’s concern that the defendant’s comment that he was questioned for several hours would lead the jury to think that he had told police he acted in self-defense was highly speculative, and in our view, no effort at clarification was necessary.
The judge’s approach, however, may have implicated the defendant’s right to silence, and, to the extent it did so, it was erroneous. In any event, since the defendant did not object (indeed, defense counsel suggested the phrasing of the question that was finally asked), the question before us is whether the error created a substantial risk of a miscarriage of justice. Commonwealth v. Alphas, 430 Mass. 8, 13 (1999). We believe it did not. The statement was brief and isolated, and we see no danger that the defendant was prejudiced in any meaningful way.
Judgments affirmed.
When the defendant testified, his own counsel questioned him about the prior convictions, evidently in an effort to blunt the impact of their introduction on cross-examination. The prosecutor did not allude to the convictions when cross-examining the defendant, although he did mention them briefly in his closing argument.
The judge stated:
“[0]n this issue of the credibility of witnesses, you may have heard evidence that the defendant was previously convicted of one or more crimes. You may consider that information only for the purpose of helping you decide whether or not to believe his present testimony and how much weight, if any, to give it. You may not draw any inference of guilt against the defendant because of prior convictions. The fact that the defendant was once found guilty of other crimes does not mean that he is guilty of these charges, and you must not consider the prior *204convictions to be any indication of guilt on these charges. You may consider the defendant’s prior convictions solely to help you determine whether or not he is a truthful witness.”
Because we conclude that there is no error, we need not consider whether the defendant’s objection was preserved.
The dissent contends that its proposed attenuation of the statute does not arise out of constitutional considerations. Post at 213. Its language suggests otherwise. In referring to the application of a previous gloss attached to the statute, see Commonwealth v. Chase, 372 Mass. 736, 749-751 (1977), and subsequent cases, the dissent alludes to the “logic and fairness” that require the exercise of discretion in allowing or excluding prior convictions. These are words that invite due process considerations. The statute contains no discretionary component. What is logical and fair is for the Legislature to decide in the first instance. We may not substitute our view on the subject unless we determine that the statute as written may, facially or as applied, conflict with a defendant’s constitutional rights.
In Commonwealth v. Cowans, 52 Mass. App. Ct. 811, 821 (2001), the Appeals Court stated, “We note for the future that when instructing the jury on *206the elements of the home invasion statute, with regard to the threatened imminent use of force, the judge should instruct. . . that the jury must determine whether the defendant intended to cause the victim fear or apprehension of immediate harm.” Since the Commonwealth did not seek further appellate review in that case, this court has not had occasion to rule on that requirement.
Previously, during direct examination, the prosecutor had asked the victim, “Now, sir, when you get very nervous, do you tend to stutter?” The victim had indicated that he did.
In his instructions to the jury, the judge noted that “[t]he fact that a person is . . . subjected to any police practices, custodial issues that some of the evidence may have shown you, none of that is evidence of guilt in this case. You are not entitled to draw any inference of guilt from any of those things.” The defendant did not request, and the judge did not give, a specific instruction on the defendant’s silence.