(concurring in result). I agree that the defendant’s appeal, at least in its current posture, must fail. The defendant *587chanced much by presenting only a facial challenge.1 See Commonwealth v. Lammi, 386 Mass. 299, 301-302 (1982) (court will not pass on validity of “hypothetical applications” of a law subject only to facial challenge). Where a constitutional construction of a challenged statute is possible, a facial challenge must be rejected. Blixt v. Blixt, 437 Mass. 649, 652 (2002), cert. denied, 537 U.S. 1189 (2003).
The defendant’s entitlement to reversal here hinged on a finding that G. L. c. 269, § 2, was susceptible of no fair reading that struck within constitutional limits. As set out in the foregoing opinion, it is not only possible, but required for us to impose a constitutional construction on § 2, foreclosing any opportunity for relief on the basis of a facial challenge. If the defendant believes that § 2, as applied to his particular situation, presents a constitutional violation, he may advance that claim by way of a motion for a new trial in the District Court. In the meantime, the judgment must stand.
The majority opinion concludes that “unlawful assembly,” *588for the purposes of § 2, must be defined as “any gathering otherwise meeting the requirements of [G. L. c. 269, § 2], the members of which have formed a common intent to ‘engage[] in a common cause ... to be accomplished with violence’ . . . , that is, where there is [evidence of acts providing probable cause to believe that there is] an ‘imminent danger . . . [of] violence.’ ” See ante at 585. See also ante at 586 n.8. While I agree that the majority’s view is indicated by prior Massachusetts decisions relating to the common law provenance of the term “unlawful assembly,” I believe it is important to emphasize that placing such a limitation on § 2 is also mandated by the First Amendment to the United States Constitution and art. 19 of the Massachusetts Declaration of Rights.
Absent the sort of limiting construction imposed on it by the majority opinion, § 2 would constitute an omnibus restraint on the right of assembly, with essentially no objectively defined restrictions on the circumstances in which it could be enforced. As a result, it would confer virtually unlimited discretion on police in the exercise of the dispersal power under § 2, posing a strong possibility that the law would be used to prohibit constitutionally protected expressive conduct.2 Such unlimited restraints on potentially protected forms of expression have been disapproved by both the United States Supreme Court and our own Supreme Judicial Court.3
In Edwards v. South Carolina, 372 U.S. 229, 233-238 (1963), the United States Supreme Court overturned convictions, of breach of the peace, of persons who had refused to obey an order to disperse from an assembly protesting discrimination, *589under a South Carolina statute that permitted arrest not only for acts of violence but also for acts that were “unjustifiable and unlawful, tending with sufficient directness to break the peace.” Id. at 234. The statute, thus, like G. L. c. 269, § 2, did not contain express limitations on the circumstances in which it could be enforced. The Court observed that such general restraints on the right of assembly pose serious First Amendment concerns. Id. at 237-238. In order to meet constitutional requirements, the Edwards court held, persons may not be prevented from exercising their right of assembly absent a showing of “a clear and present danger of a serious substantive evil that rises far above public inconvenience, annoyance or unrest.” Id. at 237. Vague menace to public “tranquility” will not suffice to displace core constitutional protections. Id. at 234-238. In the absence of any evidence of “violence or threat of violence” among members of the assembly at issue in Edwards, the Court concluded that the right of assembly had been unconstitutionally impaired by the South Carolina law. Id. at 236-238.
Similarly, in Commonwealth v. A Juvenile, 368 Mass. 580, 587-599 (1975), the Supreme Judicial Court held that G. L. c. 272, § 53, which generally proscribes “disorderly conduct,” was unconstitutional as applied to speech and expressive conduct absent some form of limiting construction. As the court stated there, to the extent that § 53, drafted as it was without any objective restrictions on how, when, or where it could be enforced, is “ ‘susceptible of application to protected expression,’ it is unconstitutionally overbroad.” Id. at 586, quoting from Gooding v. Wilson, 405 U.S. 518, 523 (1974). Along the same lines, in Commonwealth v. Jarrett, 359 Mass. 491, 497-498 (1971), the Supreme Judicial Court concluded that the crime of disturbing the peace, also potentially an omnibus restraint on protected forms of expression, is constitutional because it does not apply to conduct protected by the First Amendment and art. 19. See Commonwealth v. Welch, 444 Mass. 80, 99-100 (2005) (G. L. c. 265, § 43A, the criminal harassment statute, cannot be applied to speech protected by First Amendment).
By limiting application of § 2 to those situations in which, *590by dint of a common intent so to do, an assembly either resorts to violence or engages in acts4 supporting probable cause to believe that violence by the group is imminent, the majority opinion has ensured that no constitutional infraction of the sort identified in these above mentioned cases will occur. See Boos v. Barry, 485 U.S. 312, 330-331 (1988) (“where demonstrations turn violent, they lose their protected quality as expression under the First Amendment”). While there were surely other potential routes to this outcome — e.g., imposition of a savings clause — the majority’s approach has the support of common law precedent and also comports with relevant principles of appellate restraint. It is, for these reasons, the outcome I endorse.5
One last point: I would like to express my strong belief that the parties, in particular the Commonwealth, were seriously remiss in failing to provide us with a complete record of the *591proceedings below. While the Commonwealth might have perceived a tactical advantage in following the defendant’s lead in this regard, the prosecutor would have done well to remember his larger role as a purveyor of justice, not merely an advocate for affirmance. If it is clear that a case cannot receive adequate review absent the trial record, I would hope that the government, in future cases, will do its best to ensure that we receive a copy of the complete record. In view of our disposition of this matter, it is all but certain that this case will now require collateral review. Such inefficiency is both unnecessary and undesirable.
Although choosing not to include a transcript on appeal because he was pressing a purely facial challenge to the statute, the defendant in his brief also purports to challenge the adequacy of the judge’s juty instructions. In support of his claim, he has submitted what appear to be copies of pages from a set of model jury instructions that were provided to the jury for use during their deliberations. It is impossible to infer that these amount to a reliable record of the actual jury charge. Even were we to assume — which I cannot on the basis of the current record — that these were the instructions that the trial judge intended to give at trial, I could not be certain that the judge, in fact, so charged the jury. It is frequently the case that errors, omissions, or amplifications that depart from the judge’s written text find their way into an oral charge. The parties’ unsupported recollections of the judge’s charge offered during oral argument do not eliminate concerns about the possibility of such unintended deviations (or about the content of the charge, in general). Further, and perhaps more important, it is generally impossible to assess the adequacy of jury instructions abstracted from the underlying facts. Where, for example, an issue is not contested by the parties, even a serious error relating to that issue may not provide a basis for relief. In any event, it was plainly the defendant’s choice to proceed without a record here. Having made that choice, he cannot compel a court to reach issues that would require at least some degree of speculation about the contents of the record.
Statutes giving police broad power to arrest for speech or to order persons to disperse from assemblies also create the potential for unlawful selective enforcement. See Grayned v. Rockford, 408 U.S. 104, 108 (1972) (“laws must provide explicit standards for those who apply them”); Houston v. Hill, 482 U.S. 451, 465 (1987) (“we have repeatedly invalidated laws that provide the police with unfettered discretion to arrest individuals for words or conduct that annoy or offend them”)
By contrast, statutes placing restraints on assembly that are limited to a particular time, place, or manner have been approved in a wide variety of contexts. See, e.g., Cox v. Louisiana, 379 U.S. 559, 568-589 (1965) (ordinance prohibiting picketing near court house that disrupts normal operations of court house deemed sufficiently narrowly drawn to meet demands of First Amendment).
The reference to “acts,” ante at 586 n.8, as the requisite basis for a finding of probable cause to believe that a gathering has formed a collective intent to engage in imminent violence is an important part of the majority’s formulation of the elements of the offense described in § 2. Absent such a requirement, police would be afforded too much discretion in enforcing that provision. It is only when an assembly either engages in actual violence or commits overt acts that make it plain that such violence by the group is imminent that police may issue a valid dispersal order, at least under § 2.
It is important to note that the reading the majority imposes on G. L. c. 269, § 2, by no means trenches on police authority to control crowds or protect public safety. The law provides ample alternative mechanisms for accomplishing these ends. In the first instance, police retain general authority to make arrests whenever they have probable cause to believe a crime is being committed. Towns and cities may impose permissible “time, place, and manner” restrictions on public gatherings as a matter of local law. See, e.g., Cox v. New Hampshire, 312 U.S. 569, 576 (1941). Anyone violating such ordinances, including valid permit requirements, would be subject to arrest under local laws or ordinances without reference to G. L. c. 269, § 2. Further, within the scope of their community caretaker function, and under the general power of arrest conferred on police by G. L. c. 41, § 98, police have authority to take any reasonable protective measures whenever public safety is threatened by dangerous acts, not expressly unlawful. See, e.g., Commonwealth v. Bates, 28 Mass. App. Ct. 217, 219 & n.2 (1990) (emergency or “community caretaker” exception authorizes police to make otherwise unlawful entries or searches “to protect or preserve life or avoid serious injury”). Finally, police have the power to arrest individuals participating in lawful assemblies who are engaged in unrelated criminal acts, or who stand ready to assist others engaged in such acts. In short, nothing in the majority’s decision strips police of their broad authority to preserve the peace and ensure public safety.