(concurring in part and dissenting in part, with whom Ireland and Cordy, JJ., join). Adults who prey sexually on children are a grave menace in our society. The public *446and Legislatures in all States1 have concluded that persons convicted of such offenses may pose a continuing threat, one to be met by legislation providing means to keep track of their whereabouts and, in some circumstances, to inform residents of the communities where they reside.
It is settled in this Commonwealth that the Legislature may constitutionally impose a registration requirement on such menacing predators. In Doe v. Attorney Gen., 426 Mass. 136, 139 (1997) (Doe [No. 3]), we said the major premise underlying the then-existing Massachusetts statute2 was to “protect minors and other persons vulnerable to becoming victims of sex crimes.” In Doe v. Attorney Gen., 430 Mass. 155, 165 (1999) (Doe [No. 5]), we held that a statute tailored with particularity to meet that need would be valid under the Massachusetts Constitution. I therefore concur with the court to the extent that it upholds application of the 1999 statute,3 to require registration, before a hearing, of those convicted of sexual offenses who pose “a grave threat to children,” where the risk of reoffense “is compelling.” Doe (No. 5), supra.
But the statute now before us sweeps more broadly.4 It requires registration by persons who have engaged in consensual sexual acts between underage peers, G. L. c. 265, § 23, see Doe (No. 5), supra at 164. It requires registration by an adult man arrested in a police sting operation for soliciting another adult man to engage in consensual homosexual sex. See Doe (No. 3), supra at 137-138. The 1999 Act would require registration without a hearing — and transmission of detailed registration information to the Federal Bureau of Investigation (FBI) and local police — by individuals who pose no threat to children or other vulnerable persons.
*447Moreover, the statute is retrospective,5 requiring registration by all persons convicted of a sex offense since 1981, in some cases earlier.6 That increases the possibility of its application to persons who pose no present threat to the vulnerable members of our communities. See, e.g., Doe (No. 3), supra at 137-138.
To achieve the purpose of the legislation, as described in the preamble, in a manner that is consistent with our prior decisions and our Constitution, I conclude that the broad sweep of the 1999 legislation must be cabined as follows: First, all potential registrants may be required to provide the sex offender registry board (board), and only the board, with a current address so the board may contact them to schedule a hearing. Second, the detailed registration information (described in the Act)7 may be transmitted to law enforcement officials for only those offenders who pose “a grave threat to children and other vulnerable populations” and where their risk of reoffense “is compelling.” Doe (No. 5), supra at 165. In all other respects I respectfully dissent from the court’s conclusions.8
The Legislature stated that it was necessary for the board to *448have current addresses for all offenders so that it can offer them the constitutionally required hearings to classify each individual appropriately, according to his dangerousness and the risk of reoffense. St. 1999, c. 74, § 2. I see no constitutional difficulty in requiring all offenders to provide the board with their current addresses so that they may be reached for a classification hearing. As the court recognizes, ante at 428-431, furnishing the board with current location information is an infringement of an offender’s liberty interest, but is constitutionally permissible, provided that the board does not inadvertently stigmatize persons as “sex offenders,” as it gives, notice to them of their hearings.9 See Doe (No. 3), supra at 146 (“Government action unreasonably stigmatizing [an offender] would violate [his] constitutionally protected rights”). The intrusion should also be as minimal as possible. To that end, providing only a current home or work address should suffice. No additional information is necessary prior to a classification hearing.
The constitutional problem stems from another stated object of the 1999 Act, to “provide law enforcement with additional information critical to preventing sexual victimization and to resolve incidents involving sexual abuse promptly.” St. 1999, c. 74, § 1. The statute provides that the board is to make available to, and affirmatively pass on to the FBI and other law enforcement officials nationwide, detailed information about all those who register. G. L. c. 6, §§ 178D, 178E. Because the statute is retrospective in its effect, an adult man arrested in 1990 in a police sting operation for soliciting another adult man at a highway rest stop to engage in consensual homosexual sex *449may have lived that down and achieved success and respect in his community. Doe (No. 3), supra at 137-138. Now he would be required to register, and thus notify his local police, without any opportunity to show what he likely could: that he is not a danger to children or other vulnerable persons. Making a person register with the police, not in connection with any planned activity, is the factor that introduces a changed relationship between citizen and State, and “is in principle quite alien to our traditions, a relationship which when generalized has been the hallmark of totalitarian government.” Doe (No. 5), supra at 162, quoting Doe (No. 3), supra at 150 (Fried, J., concurring).
In Doe (No. 3), supra at 144, we held that a person required to register by the 1996 statute had “a liberty and privacy interest protected by the Constitution of the Commonwealth that entitle[d] him to procedural due process.” As the court recognizes, ante at 431, we said a combination of five factors led to that conclusion: “(1) the requirement that he register with local police; (2) the disclosure of accumulated personal information on request; (3) the possible harm to his earning capacity; (4) the harm to his reputation; and, most important, (5) the statutory branding of him as a public danger, a sex offender. That statutory classification implicitly announces that, in the eyes of the State, [he] presents a risk of committing a sex offense.” (Emphasis added.) Doe (No. 3), supra at 144.10 The court concluded: “[I]t is contrary to the principle of fundamental fairness that underlies the concept of due process of law to deny the plaintiff a hearing at which the evidence might show that he is not a threat to children and other vulnerable persons whom the act seeks to protect and that disclosure is not needed when balanced against the public need to which the sex offender act responded.” Id. at 146.
The question of disclosing information to the public is not involved in the first operational phase of the new statute and is *450not presented by these appeals. But, contrary to what the court now claims, we made quite clear in Doe (No. 5) that registration with the police itself “engages serious liberty interests, and presents an ‘importantly distinct kind of constitutional danger.’ ” Id. at 162, quoting Doe (No. 3), supra at 149 (Fried, J., concurring).11 I recognize that the police and the FBI already have access through computerized files to large amounts of information on anyone who has been convicted of a criminal offense. Ante at 438. However, the critical difference under the 1999 sex offender registration statute is that some persons, those labeled as “sex offenders,” are singled out and brought to the attention of the law enforcement agencies in the municipalities in which they live and work. This is not a minimal intrusion on sex offenders’ liberty interests. The authorities may have all kinds of information on individuals in this country. But registration, as Justice Fried put it, “forces an action on the person required to register. It is a continuing, intrusive, and humiliating regulation of the person himself.” Doe (No. 3), supra at 149 (Fried, J., concurring).12 Moreover, as the Commonwealth itself recognizes, existing data bases on those convicted of sex (or other) offenses do not necessarily include current information on an offender’s location. Hitherto the State has not had a right to demand that an individual keep it and the police regularly apprised of his movements at home and at work.
*451In Doe (No. 5), supra at 165, we recognized that situations may exist “where the danger to be prevented is grave, and the risk of reoffense great, such that the promulgation of regulations narrowly tailored to allow for automatic registration may clarify and simplify the enforcement of the sex offender registration act in a manner that comports with procedural due process.” Contrary to the court’s suggestions, the only possible justification for forwarding detailed information about past offenders to law enforcement officials is that the Legislature has determined that a sex offender poses a risk to vulnerable members of our society. To provide law enforcement officials with access to information that we have never required citizens to furnish, where there is no reasonable risk that they pose any threat to their fellow citizens, is manifestly overbroad. As to the court’s suggestion that the police may take the names of every person in the community and search a data base to see whom they think might present a danger, ante at 434, in our society we do not give the police such unfettered power to appraise every person in every community.
The court notes repeatedly, ante at 432 n.23, 433, 439 n.31, that in Doe (No. 3) and Doe (No. 5) we cited with approval the cognate New Jersey statute and Doe v. Poritz, 142 N.J. 1 (1995), in which the Supreme Court of New Jersey “identified an infringement of a privacy interest from the public disclosure of information about a sex offender, distinguishing those offenders as to whom information would only be provided to law enforcement.” Ante at 432 n.23. But the court fails to note that the New Jersey statute is far less broad in its retrospective reach, and does not include within its scope offenders who pose little or no threat to the vulnerable. The New Jersey statute, as it applies to persons convicted before its effective date, covers only a few offenses •— aggravated sexual assault, sexual assault, aggravated criminal sexual contact, and kidnapping — and then only when those previously convicted of those offenses are found to be “repetitive” and “compulsive” offenders. See N.J. Stat. Ann. § 2C:7-2b(1), (2) (West 1995). The retrospective reach of the Massachusetts statute is not cabined in this manner, and the constitutional infirmity arises precisely because it encompasses individuals who pose no threat to the vulnerable.
*452The Commonwealth argues that registration by mail, with attendant notification to police, is a “minimal” imposition on a constitutionally protected liberty. Today, three Justices of this court accept that view. Ante at 428.13 But that is unrealistic, and inconsistent with our holdings in Doe (No. 3), supra, and Doe (No. 5), supra. The 1999 Act requires thousands of citizens to write to the board, and thus to alert their local police, every time they move or change a job. To be reminded again and again of an offense years past, such as a teenage sexual encounter, that does not menace any vulnerable person now but that is swept into a grim, categorized term, “sex offense,” would not be seen by most Americans as a minimal imposition.14
Forced registration, whether in person, by mail, by the Inter*453net, or otherwise, is what brings about the fundamental change of which Justice Fried wrote: “[W]hile activities, professions, or relationships may be regulated, we do not have a general regime regulating adult competent persons as such. . . . Persons are left to choose freely and if they make the wrong choices they are subject to retrospective condemnation and punishment. This is not merely a conceptual difference. It is a profound expression of our Constitution’s conception of human nature and of the relation of individuals to the State.” Doe (No. 3), supra at 147-148 (Fried, J., concurring).
The court suggests that it is not beyond the Legislature’s power to prescribe a more expedient way for the government to locate citizens and monitor their activities, when it has a legitimate reason for doing so. But what is happening here is not a neutral governmental act of collecting information, such as occurs during the census, for example. It is affixing a badge of infamy,15 a “continuing, intrusive, and humiliating” regulation of persons who may be found to pose no danger and hence would be exempt if they were given the opportunity for a hearing before being required to register. Doe (No. 3), supra at 149 (Fried, J., concurring). The court’s suggestion that a “sex of-, fender” is not “branded” as a public danger because only the police will have access to the names of those registered, ante at 436, is inconsistent with our prior rulings. The police already have access to the criminal history records of all those convicted of crimes. The 1999 statute does something more: it informs the police that “in the eyes of the State, [an offender] presents a risk of committing a sex offense,” it brands him “as a public danger.” Doe (No. 3), supra at 144.
The police can, of course, obtain access to information on convicted persons whenever they have reason to. But I do not agree with the court that “the mere fact that that information has been assembled by the board in a more convenient format does not implicate any constitutionally protected privacy interest.” Ante at 437. The ability of the police to access information on convicted persons, as the particularized need arises, is very different from, for example, sending to a police *454department what may amount to a list of young persons who have engaged in consensual sexual activities but have done nothing to endanger children or other vulnerable persons. To pass constitutional muster, the government must show more than a claim that its method is expedient.
The application of the Massachusetts statute to young persons raises particular concerns because of the large number of students in this Commonwealth. They are a great feature of Massachusetts life, but inevitably they commit occasional sexual offenses. Colleges and universities are trying to deal with the problem, but the cases that arise are often conflicted. See, e.g., Schaer v. Brandeis Univ., 432 Mass. 474 (2000). See also In Alleged Date Rape, Harvard Split on Call for Lesser Penalty, Boston Globe, March 9, 1999, at A1 (two friends spent night together drinking; although intercourse occurred in context where defendant claimed consent was ambiguous, defendant pleaded guilty to indecent assault). Teenagers are another reason for concern at the broad sweep of the statute. In our society, there are teenage idols and models who flaunt sex. Much as we may regret it, sexual display and activity begin early.
Because the court sees no constitutional difference between those who prey on the vulnerable and those who have been convicted of sex offenses but pose no threat to the vulnerable, I see no limit to the new policy constitutionally ratified here. May every person convicted of any crime be required to register and have their registration information disseminated to police nationwide for years after he has completed whatever punishment society has determined he must undergo?
It is true that many other State courts have found sex offender registration constitutional. But the Massachusetts statute sweeps more broadly than most. It is far broader than the Federal statute, the Wetterling Act. That statute narrowly defines sex offenders as those persons who engage in violent sexual acts against children and other vulnerable populations. It is not retrospective, and hence would not require registration of anyone convicted before the effective date of our law, September 10, 1999. The Wetterling Act also does not require registration *455of juveniles adjudged delinquent, or persons under eighteen years of age who were convicted of conduct that was criminal only because of the victim’s age. See 42 U.S.C. § 14071(a)(3)(A) (2000).16
This court has on more than one occasion provided clear guidance to the Legislature that a statute to protect children and other vulnerable persons from adults who prey on them by keeping track of them and alerting police and local communities to their presence is constitutionally valid under our Constitution if it is tailored to meet- that need. This act goes far beyond that need. To the extent — the great extent — that it does, I conclude that it is inconsistent with the principles on which this Commonwealth was founded.
See Roe v. Farwell, 999 F. Supp. 174, 177 n.1 (D. Mass. 1998) (all fifty States have some version of a sex offender registration and notification statute).
General Laws c. 6, §§ 178C-178O, inserted by St. 1996, c. 239, § 1.
“An Act improving the sex offender registry and establishing civil commitment and community parole supervision for life for sex offenders,” G. L. c. 6, §§ 178C-178P, as appearing in St. 1999, c. 74, § 2 (Act).
The Act adds several new offenses under the definition of “[s]ex offense,” including enticing someone “away" for prostitution, G. L. c. 272, § 2; incestuous marriage or intercourse, G. L. c. 272, § 17; and possession of child pornography, G. L. c. 272, § 9C.
As the court notes, ante at 420 n.5, we are concerned here with the statute only as it applies retrospectively. The judge below ruled “that the statute provides sufficient due process protection as to those offenders convicted . . . on or after December 12, 1999,” and the plaintiffs do not challenge that aspect of his order. Id.
Under the statute, a “[s]ex offender” is someone who “has been convicted of a sex offense or who has been adjudicated as a youthful offender or as a delinquent juvenile by reason of a sex offense or a person released from incarceration or parole or probation supervision or custody with the department of youth services for such a conviction or adjudication or a person who has been adjudicated a sexually dangerous person under section 14 of chapter 123A, as in force at the time of adjudication, or a person released from civil commitment pursuant to section 9 of said chapter 123A, whichever last occurs, on or after August 1, 1981.” G. L. c. 6, § 178C.
The registration information provided to the police, prior to an individualized hearing, is substantial. It includes name, date and place of birth, sex, race, height, weight, eye and hair color, social security number, and home and work addresses; a photograph and set of fingerprints; a description of the offense; and any other information that may be useful in identifying the offender or his risk of reoffense. G. L. c. 6, § 178D. The board transmits the registration data, which it collects from a variety of sources, to the FBI and to local police departments immediately on mail-in registration by offenders neither in custody nor on probation or parole. G. L. c. 6, § 178E.
In Doe v. Attorney Gen., 430 Mass. 155, 166 (1999) (Doe [No. 5]), supra, we held that “[t]he burden of proof will be on the sex offender board to *448establish at the hearing that the offender poses a risk to vulnerable populations.” I note that the 1999 Act places the burden of proof on persons wishing to be relieved of the registration requirement: The burden of proof “shall be on the offender to prove” that the offender’s “criminal history do[es] not indicate a risk of reoffense or a danger to the public.” G. L. c. 6, § 178K (2) (d).
The board is required to mail registration forms to offenders who are not incarcerated, on probation, or on parole, and it will annually mail verification forms to each offender. G. L. c. 6, §§ 178F, 178F½. In November, 1999, the board mailed 2,500 registration forms to offenders. To ensure that no person may inadvertently be publicly stigmatized as a “sex offender,” see Doe (No. 3), supra at 144, and to foreclose the inadvertent public dissemination of sex offender registration, the envelope or other external cover of any communication to offenders should not identify the board as the sender.
The court states, ante at 431-432, that all these factors except the first — police knowledge of the offender’s registration — have been eliminated under the 1999 statute. The court reaches this conclusion because public disclosure and its potential adverse effects no longer automatically accompany registration. The court does not explain how the fifth and most important factor — statutory branding of the offender as a public danger — has been eliminated, or even lessened under the new statute.
The court incorrectly suggests that, in Doe (No. 3), supra at 146, and Doe (No. 5), supra at 155, we held that a preregistration hearing was required because, under the 1996 statute, registration “was automatically coupled with” public disclosure. Ante at 433. In Doe (No. 5) we were careful to note that registration itself (without reference to public notification) “engages serious liberty interests.” Id. at 162. As Justice Fried noted, the act of registration alone is objectionable because it “forces an action on the person required to register.” Doe (No. 3), supra at 149 (Fried, J., concurring). We did say that the liberty interest was “heightened” by the public access to registration information that the statute permits. Doe (No. 5), supra at 163. We did not say that, without public access to the information, a preregistration hearing was not required.
The court says that the transmission of registration information to law enforcement does not “force) ] an action on the person required to register.” Ante at 436 n.27. The distinction is meaningless; dissemination of registration information to law enforcement follows automatically on registration. It is part and parcel of the act of registration.
Justice Cowin, in her concurring opinion, agrees that the statute is constitutionally infirm to the extent that the statutory scheme encompasses certain individuals or categories of individuals whom neither the Legislature nor the board could rationally find present a threat to vulnerable persons. Ante at 442-443 (Cowin, J., concurring). She concludes that the requirement that the board transmit registration data to law enforcement authorities is unconstitutional as it applies to such persons, since such transmission will take place prior to the holding of an administrative proceeding which could establish their “non-dangerous” status. Id. at 445 (Cowin, J., concurring). Under today’s ruling the board;has authority to transmit immediately to law enforcement all registration information of all those classified as “sex offenders.” Individuals who choose to bring an “as applied” challenge will be forced to seek emergency injunctive relief to prevent the transmission of their information to police.
The requirements of the 1999 Act may be especially burdensome for homeless persons. Such persons must register with the board and therefore may violate the act every three months, G. L. c. 6, § 178F, 178H (c), with the result that homeless persons may be subject in rapid order to multiple convictions and substantial criminal penalties. One of the named plaintiffs, Daniel Doe, is a fifty-six year old homeless man of limited mental capacity. He has been a ward of the State since a young age and has never held a steady job, nor lived in a house or apartment of his own. Under the order for hearings before the board mandated by § 178K (3), Doe will not receive a hearing until many other categories of offenders have been reached. Should he fail during this potentially lengthy time to comply with his duty to verify his registration data every ninety days, he is subject to criminal prosecution. G. L. c. 6, §§ 178F, 178F½. Should he fail to verify his registration data a third time, he is subject to a mandatory minimum sentence of five years in the State prison. G. L. c. 6, § 178H (c). If Daniel Doe is in fact incapable of complying with the rigorous requirements of keeping the board informed of his current whereabouts because of mental illness, he may challenge the validity of registration with the board as it applies to him.
The Supreme Court of California has described sex offender registration as an “ignominious badge.” In re Birch, 10 Cal. 3d 314, 322 (1973).
The Federal government requires States, as a condition of receiving certain Federal funding, to establish a sex offender registration and notification system and to participate in a national sex offender registry. See 42 U.S.C. §§ 14071 et seq. (2000).