                  FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

THE AMERICAN CIVIL LIBERTIES            
UNION OF NEVADA; DOES 1-8, and
Does A-S,
                Plaintiffs-Appellees,
                 v.
CATHERINE CORTEZ MASTO,
Esquire, Attorney General of the
State of Nevada; GERALD HAFEN,
Director of the Nevada
Department of Public Safety;
BERNARD W. CURTIS, Chief, Parole
and Probation Division of the
Nevada Department of Public             
Safety; CAPTAIN P.K. O’NEILL,
Chief, Records and Technology
Division of the Nevada
Department of Public Safety,
             Defendants-Appellants,
                and
MICHAEL HALEY, Sheriff of the
Washoe County Sheriff’s Office;
MICHAEL POEHLMAN, Chief of the
Reno Police Department; RICHARD
GAMMICK, District Attorney of
Washoe County;
                                        




                             1499
1500                   ACLU v. MASTO


DOUGLAS GILLESPIE, Sheriff of the       
Las Vegas Metropolitan Police
Department; JOSEPH FORTI, Chief              No. 08-17471
of the North Las Vegas Police
Department; DAVID ROGER, District             D.C. No.
                                            2:08-cv-00822-
Attorney of Clark County;
RICHARD PERKINS, Chief,                       JCM-PAL
Henderson Police Department,
                      Defendants.
                                        

THE AMERICAN CIVIL LIBERTIES            
UNION OF NEVADA; DOES 1-8, and
Does A-S,
                Plaintiffs-Appellees,
                 v.
CATHERINE CORTEZ MASTO,
Esquire, Attorney General of the
State of Nevada; GERALD HAFEN,
Director of the Nevada
Department of Public Safety;            
BERNARD W. CURTIS, Chief, Parole
and Probation Division of the
Nevada Department of Public
Safety; CAPTAIN P.K. O’NEILL,
Chief, Records and Technology
Division of the Nevada
Department of Public Safety,
             Defendants-Appellants,
                and
                                        
                          ACLU v. MASTO                           1501


MICHAEL HALEY, Sheriff of the              
Washoe County Sheriff’s Office;
MICHAEL POEHLMAN, Chief of the
Reno Police Department; RICHARD
GAMMICK, District Attorney of
Washoe County; DOUGLAS                             No. 09-16008
GILLESPIE, Sheriff of the Las Vegas                  D.C. No.
Metropolitan Police Department;                  2:08-cv-00822-
JOSEPH FORTI, Chief of the North                    JCM-PAL
Las Vegas Police Department;                         OPINION
DAVID ROGER, District Attorney of
Clark County; RICHARD PERKINS,
Chief, Henderson Police
Department,
                         Defendants.
                                           
         Appeal from the United States District Court
                  for the District of Nevada
          James C. Mahan, District Judge, Presiding

                  Argued and Submitted
        December 7, 2011—San Francisco, California

                     Filed February 10, 2012

 Before: Stephen S. Trott and Carlos T. Bea, Circuit Judges,
      and William H. Stafford, Senior District Judge.*

                      Opinion by Judge Trott




  *The Honorable William H. Stafford, Jr., Senior District Judge for the
U.S. District Court for Northern Florida, sitting by designation.
1504                  ACLU v. MASTO




                       COUNSEL

Margaret A. McLetchie, ACLU of Nevada, Las Vegas,
Nevada; and Robert Langford, Langford & Associates, Las
Vegas, Nevada, for the plaintiffs-appellees.

Binu G. Palal, Nevada Attorney General’s Office, Las Vegas,
Nevada, for the defendants-appellants.
                       ACLU v. MASTO                       1505
                          OPINION

TROTT, Circuit Judge:

   The State of Nevada appeals the district court’s permanent
injunction prohibiting the retroactive application of two
Nevada laws: Assembly Bill 579, expanding the scope of sex
offender registration and notification requirements, and Sen-
ate Bill 471, imposing, inter alia, residency and movement
restrictions on certain sex offenders. The district court perma-
nently enjoined retroactive application of both bills on the
grounds that they violated the Ex Post Facto Clause of the
United States Constitution, the Contract Clause of the United
States Constitution, the Double Jeopardy Clause of the Fifth
Amendment, and the Due Process Clause of the Fourteenth
Amendment. With respect to Assembly Bill 579, we hold that
its retroactive application is constitutionally sound, and we
reverse. With respect to Senate Bill 471, we conclude that our
consideration of its disputed provisions was mooted by the
State of Nevada’s authoritative judicial admission that —
regardless of the existence of the injunction — the State will
not retroactively impose residency and movement restrictions.
Because the State’s concession moots its own appeal, we
remand to the district court to consider vacating its Order as
to Senate Bill 471 in favor of a binding consent decree. But
if no consent decree can be negotiated, our dismissal of the
State’s appeal will leave the district court’s injunction in
vigor.

                               I

                      BACKGROUND

   In July 2007, the State of Nevada passed into law two stat-
utes (“Revised Laws”) imposing various requirements on
individuals convicted of sexual offenses, Assembly Bill 579
(“AB 579”) and Senate Bill 471 (“SB 471”).
1506                    ACLU v. MASTO
   Nevada’s AB 579 is best understood against the backdrop
of the federal Sex Offender Registration and Notification Act
(“SORNA”), enacted as a section of the Adam Walsh Child
Protection and Safety Act of 2006 (“Adam Walsh Act”). Pub.
L. No. 109-248 (2006). SORNA encourages state govern-
ments, U.S. territories, and federally recognized Indian tribes
to adopt a standardized sex offender registration and notifica-
tion regime. 42 U.S.C. § 16912. It prescribes detailed registra-
tion and notification requirements to be adopted by each
jurisdiction. To encourage implementation of the scheme,
SORNA reduces federal law enforcement funds to jurisdic-
tions that fail to adopt it, id. § 16925, and authorizes dispensa-
tion of grants to offset the cost of implementation, id.
§ 16926. SORNA also created the “Office of Sex Offender
Sentencing, Monitoring, Apprehending, Registering, and
Tracking (“SMART Office”) within the Department of Jus-
tice. Id. § 16945. The SMART Office assists jurisdictions
with implementation of SORNA’s registration and notifica-
tion program and monitors compliance.

   The State of Nevada passed AB 579 into law on June 13,
2007 to bring Nevada into compliance with SORNA. The law
replaced Nevada’s existing registration requirements with the
scheme laid out in SORNA. The central innovation of
SORNA and AB 579 is a classification system for sex offend-
ers that places them into one of three risk tiers based solely
on their crime of conviction. Registration and notification
requirements are then keyed to an offender’s tier classifica-
tion. Largely using the language of SORNA, AB 579 also (1)
expands the category of individuals required to register, (2)
expands the time period during which sex offenders are sub-
ject to registration requirements, (3) requires sex offenders to
register in person, and (4) obliges law enforcement actively to
provide notice of the status of certain registrants. The
SMART Office determined that after passage of AB 579
                           ACLU v. MASTO                             1507
Nevada had “substantially implemented” SORNA require-
ments.1

   AB 579 goes beyond SORNA in its requirement that law
enforcement provide public notice of the status of certain sex
offenders. For example, SORNA requires that an appropriate
official provide notice of an individual’s sex offender status
to “each school and public housing agency” in the area where
a sex offender resides. Id. § 16921(b)(2). Adding to this man-
date, AB 579 requires law enforcement also to provide notifi-
cation to youth organizations and religious organizations. AB
579 § 29(2). Additionally, for Tier III offenders (the most
serious offenders), AB 579 obligates law enforcement to pro-
vide updated status information to “members of the public
who are likely to encounter the offender.” Id. § 29(2)(a)(4).

   Nevada’s governor signed SB 471 into law the day after he
signed AB 579, and the relevant provisions went into effect
on October 1, 2007. In the provisions at issue in this action,
SB 471 requires Nevada courts to include movement and resi-
dency restrictions in the term of probation, parole, or lifetime
supervision imposed by a court upon individuals convicted of
a sexual offense.2 The law commands that sex offenders
placed on lifetime supervision may not “knowingly be within
500 feet of any place” or reside anywhere “located within
1,000 feet of any place” that is “designed primarily for use by
or for children.” SB 471 §§ 8(3), (4). Depending on their
crime of conviction, parolees and probationers who are Tier
III offenders are subject also to the movement restriction
and/or the residency restriction. See id. §§ 2(1)(m), (2)(a)
  1
     See Press Release, Department of Justice, Justice Department
Announces Four More Jurisdictions Implement Sex Offender Registration
and Notification Act (May 12, 2011), available at http://www.ojp.
usdoj.gov/newsroom/pressreleases/2011/SMART11102.htm.
   2
     Lifetime supervision is a special sentence imposed by a court on every
defendant “convicted of a sexual offense.” Nev. Rev. Stat. § 176.0931(1).
Lifetime supervision commences after any period of probation or parole.
Id. § 176.0931(2).
1508                          ACLU v. MASTO
(pertaining to probation and suspended sentences); id.
§§ 9(1)(k)(1), 10(1)(a) (pertaining to parole). Although SB
471 contains several other provisions, Plaintiffs’ Amended
Complaint challenged only the provisions of SB 471 impos-
ing movement and residency restrictions and our decision is
limited to those requirements.3

   The American Civil Liberties Union of Nevada (“ACLU”),
together with several unnamed Does, all individuals convicted
of sexual offenses (together, “Plaintiffs”), brought a civil
action challenging both facially and as applied the retroactive
application of AB 579 and SB 471. They alleged that retroac-
tive application of the new laws would violate a litany of state
and federal constitutional provisions, and they requested
declarative and injunctive relief. The complaint named as
defendants Nevada’s Attorney General, several officials in
Nevada’s Department of Public Safety (responsible for
Nevada’s parole and probation services), and various local
law enforcement officials, all in their official capacity.

   On June 30, 2008, United States District Court Judge James
C. Mahan, ruling from the bench, granted a preliminary
injunction against retroactive application of both laws. After
the court issued the preliminary injunction, Plaintiffs agreed
to a stipulation with the local law enforcement defendants that
dismissed them from the case. The stipulation specified that
the dismissal was premised on the condition that the dis-
missed defendants would abide by the preliminary injunction
and “any other injunction or declarative relief granted” by the
court.
  3
    In their reply brief to the district court, Plaintiffs did request relief from
retroactive application of the provisions of SB 471 authorizing collection
of biological samples and electronic monitoring of sex offenders. See SB
471 §§ 2, 8, 10. Plaintiffs never amended their complaint to include this
cause of action, and the district court was explicit that the injunction did
not extend to electronic monitoring. A challenge to those provisions— or
any of the provisions of SB 471 other than its residency and movement
restrictions — is not before us.
                        ACLU v. MASTO                          1509
   On September 10, 2008, Judge Mahan issued a permanent
injunction and ordered the Plaintiffs to draft an order granting
the injunction. On October 7th, Judge Mahan signed the
Plaintiffs’ order, which enjoined retroactive application of
both laws on the federal constitutional grounds that their
application to offenders convicted before the dates the two
laws became effective was a violation of procedural due pro-
cess, the Ex Post Facto Clause and the Double Jeopardy
Clause. The only discernable reasoning articulated by the
court for its decision, under the pressure of an expedited
schedule, was that

      It is as though the legislature passes a law that says
      anyone who is ever convicted of burglary must now
      serve an additional five years in prison no matter
      when he or she was convicted regardless of the fact
      that they’ve been law-abiding citizens since their
      release from prison. That’s not fair.

The court also relied on “the Contracts clauses of the U.S. and
Nevada Constitutions,” but it did so without analysis or expla-
nation. The remaining defendants (together “the State” or
“Nevada”) now appeal that decision (Appeal No. 08-17471).

   After issuing the permanent injunction, the district court
awarded Plaintiffs $145,823.50 in attorneys’ fees as the pre-
vailing party under 42 U.S.C. § 1988(b). The State did not
appeal the award of attorneys’ fees, but instead it moved the
court to stay the payment pending their appeal on the merits
pursuant to Federal Rule of Civil Procedure 62(d). The court
denied the State’s request for a stay, prompting the State to
file an appeal of that order (Appeal No. 09-16008), which was
consolidated with the State’s appeal of the permanent injunc-
tion.

 II    JURISDICTION AND STANDARD OF REVIEW

  We have jurisdiction under 28 U.S.C. § 1291. The district
court’s grant of injunctive relief “involves factual, legal, and
1510                    ACLU v. MASTO
discretionary components.” Walters v. Reno, 145 F.3d 1032,
1047 (9th Cir. 1998). We review the district court’s legal con-
clusions de novo, its factual findings for clear error, and the
scope of relief for abuse of discretion. Id. The district court’s
decision to grant or deny a stay is reviewed for abuse of dis-
cretion. In re Combined Metals Reduction Co., 557 F.2d 179,
193 (9th Cir. 1977).

                              III

                           ANALYSIS

A.     Assembly Bill 579

  1.    Ex Post Facto and Double Jeopardy Clause

   [1] The Ex Post Facto Clause of the Constitution prohibits
our state and federal governments from retroactively impos-
ing additional punishment for commission of a criminal
offense. U.S. Const. art. I, §§ 9, cl. 3. The Double Jeopardy
Clause similarly prohibits subjecting a person to jeopardy of
multiple punishments for the same criminal act. U.S. Const.
amend. V. Under both constitutional clauses, courts apply the
identical two-step test to determine whether a newly enacted
legislative scheme constitutes an additional form of punish-
ment. Russell v. Gregoire, 124 F.3d 1079, 1086 n.6 (9th Cir.
1997) (holding that Double Jeopardy Clause determination is
analogous to Ex Post Facto Clause determination); see Hatton
v. Bonner, 356 F.3d 955, 961 (9th Cir. 2004).

   [2] The first step of the inquiry requires courts to deter-
mine whether the legislature intended to impose a criminal
punishment or whether its intent was to enact a nonpunitive
regulatory scheme. Smith v. Doe, 538 U.S. 84, 92 (2003). If
the legislature did intend to impose a criminal punishment,
that is the end of the inquiry — the law may not be applied
retroactively. Id. However, if the legislature’s intent was to
create a civil regulatory regime, we must move to the second
                          ACLU v. MASTO                           1511
step of the inquiry. There, the issue is whether the law is “so
punitive either in purpose or effect as to negate the State’s
intention to deem it civil.” Id. (internal quotation marks and
alteration omitted).

   The Supreme Court held in Smith v. Doe that Alaska’s sex
offender registration and notification scheme did not consti-
tute unconstitutional retroactive punishment. Id. at 105-06.
Following the Court’s guidance in Smith, we upheld the retro-
active application of a California sex offender registration
statute, which contained several provisions that differ from
the Alaska statute, Hatton, 356 F.3d at 967, and we follow
that guidance here.

   In Hatton, the state law we upheld was not enacted pursu-
ant to SORNA and we have not explicitly ruled on the consti-
tutionality of retroactive application of SORNA-inspired
requirements. Many of our sister circuits, however, have con-
sidered this issue. Unanimously they have concluded that
retroactive imposition of SORNA requirements is constitu-
tional.4 Because Nevada’s version of SORNA does not con-
tain any registration provision that materially distinguishes it
from Smith, we join them in concluding that the requirements
of AB 579 do not constitute retroactive punishment in viola-
tion of the Ex Post Facto Clause or Double Jeopardy Clause.

      a.   Legislative Intent

   The first inquiry is whether the legislature “ ‘indicated
either expressly or impliedly a preference for one label or
another’ ” — that is, civil or criminal. Smith, 538 U.S. at 93
(quoting Hudson v. United States, 522 U.S. 93, 99 (1997)).
  4
   United States v. W.B.H, ___ F.3d ___, 2011 WL 6156956, at *11 (11th
Cir. Dec. 13, 2011); United States v. Leach, 639 F.3d 769, 773 (7th Cir.
2011); United States v. Young, 585 F.3d 199, 206 (5th Cir. 2009) (per
curiam); United States v. May, 535 F.3d 912, 919 (8th Cir. 2008); United
States v. Hinckley, 550 F.3d 926, 939 (10th Cir. 2008).
1512                    ACLU v. MASTO
This issue is “one of statutory construction,” Seling v. Young,
531 U.S. 250, 261 (2001), that looks to the “statute’s text and
its structure to determine the legislative objective,” Smith, 538
U.S. at 92. We review this question of statutory interpretation
de novo. Ileto v. Glock, Inc., 565 F.3d 1126, 1131 (9th Cir.
2009).

   [3] The Legislative Counsel’s Digest prefacing AB 579
states that its purpose is to further the public safety goals of
the federal Adam Walsh Act. AB 579, 1; see also Nevadans
for Prot. Prop. Rights, Inc. v. Heller, 141 P.3d 1235, 1246
(Nev. 2006) (relying upon the Legislative Counsel’s Digest to
determine legislative intent). The preface explains that AB
579 was enacted “[i]n furtherance of [the] purpose” of the
Adam Walsh Act, which it recognizes was to “protect the
public by establishing a comprehensive national system for
the registration of sex offenders . . . .” AB 579, 1. The pref-
ace’s characterization of the United States Congress’s intent
in passing SORNA is apt. SORNA states on its face that its
purpose is to “protect the public from sex offenders and
offenders against children.” 42 U.S.C. § 16901. Congress was
motivated by the desire to close gaps in jurisdictions’ sex
offender registries left open after earlier federal efforts to
encourage uniform national registration requirements. See
United States v. Begay, 622 F.3d 1187, 1190 (9th Cir. 2010),
cert. denied, ___ U.S. ___, 131 S. Ct. 3026 (2011).

   The regulatory explanation of purpose on the face of AB
579 is substantiated by its legislative history and the structure
of the bill. The bill was drafted by the Office of the Attorney
General with the express objective of bringing Nevada into
compliance with SORNA. The bill adopts the registration and
notification program detailed in SORNA, and each of the pro-
visions challenged by Plaintiffs closely tracks the provisions
of SORNA. In sum, the text and structure of AB 579 evinces
the Nevada legislature’s intent to adopt a civil regulatory
regime in alignment with the public safety rationale that moti-
                        ACLU v. MASTO                       1513
vated the United States Congress to pass the federal Adam
Walsh Act.

   Plaintiffs’ arguments do not undermine this clear evidence
of legislative intent. It is true that AB 579’s statutory changes
are codified under the section of Nevada state code titled
“Procedure in Criminal Cases.” The manner of codification
can be indicative of the legislature’s intent to deem a law civil
or criminal. See Hatton, 356 F.3d at 962. The Supreme Court
has made clear, however, that the “location and labels of a
statutory provision” are not dispositive indicia of legislative
intent and must be considered in context. Smith, 538 U.S. at
94.

   In this case, the placement of the codification of AB 579 is
not illuminating evidence of legislative intent because it
amends the sex offender registration scheme previously codi-
fied under Nevada’s criminal code. The Nevada Supreme
Court had previously held that those antecedent registration
and notification requirements “were not intended to impose a
penal consequence but were instead implemented to protect
the community and assist law enforcement in solving crimes.”
Nollette v. State, 46 P.3d 87, 91-92 (Nev. 2002). Thus, AB
579 amounts to an expansion of a registration and notification
regime that the Nevada Supreme Court has already deter-
mined is civil in intent, despite its site of codification. See
Hatton, 356 F.3d at 962 (relying on state court interpretation
of legislative intent). There is no indication that the intent of
the Nevada legislature was to transform the antecedent public
safety oriented system into a form of punishment simply
through expanding the scope of its requirements. Though
many of the AB 579 requirements “relate to criminal adminis-
tration” because they are administered as conditions imposed
upon an offender’s release from prison, “they are not in them-
selves punitive.” Smith 538 U.S. at 95.

   Plaintiffs also point to the fact that AB 579 mandates regis-
tration procedures rather than delegating responsibility for
1514                     ACLU v. MASTO
their creation to an administrative agency, as did the Alaska
law at issue in Smith. See id. at 96. AB 579’s detailed require-
ments for categorizing sex offender status and maintaining a
registry, however, remain wholly unlike the procedural “safe-
guards associated with the criminal process.” Id. Nevada
adopted nearly wholesale a regulatory scheme drafted by
Congress — there was little left to delegate. The inclusion in
AB 579 of a criminal penalty for failure to comply with regis-
tration requirements does not distinguish it from the law at
issue in Smith, which also criminalized non-compliance. Id.

  [4] We conclude that the intent of the Nevada legislature
in passing AB 579 was to create a civil regulatory regime
with the purpose of enhancing public safety.

    b.   Punitive Effect

   We turn to the second inquiry: “[W]hether the statutory
scheme is so punitive either in purpose or effect as to negate
the State’s intention to deem it civil.” Id. at 92 (internal quota-
tion marks and alteration omitted). In conducting this inquiry,
“only the clearest proof” of punitive effect is sufficient to
override the Nevada legislature’s intent to create a civil regu-
lation. Id. (internal quotation marks omitted). Given this high
burden, “even a showing that most of the relevant factors
weigh in favor of considering a punishment criminal in nature
may be insufficient to transform it into a criminal punish-
ment.” United States v. Reveles, 660 F.3d 1138, 1143 (9th Cir.
2011). With all respect to the district court, we reject its anal-
ogy of these statutes to returning a burglar to prison for five
years after the service of his sentence.

   The Smith Court turned to the factors laid out in Kennedy
v. Mendoza-Martinez, 372 U.S. 144, 168-69 (1963), as a “use-
ful framework” for evaluating punitive effect. Smith, 538 U.S.
at 97. The Court focused on five of the Mendoza-Martinez
factors as most relevant in evaluating the registration and
notification law at issue. Those five factors are the degree to
                        ACLU v. MASTO                       1515
which the regulatory scheme imposes a sanction that (1) has
historically been regarded as punishment; (2) constitutes an
affirmative disability or restraint; (3) promotes the traditional
aims of punishment; (4) is rationally connected to a nonpuni-
tive purpose; and (5) is excessive in relation to the identified
nonpunitive purpose. Id. The Court also addressed the two
remaining Mendoza-Martinez factors, but concluded that they
were of “little weight” in the context of sex offender registra-
tion legislation. Id. at 105. Those factors are (6) whether the
sanction requires a finding of scienter and (7) whether the
sanction applies to behavior that is already a crime. Id. We
evaluate each of these factors in turn.

       i   Historical Form of Punishment

   Smith rejected analogies between sex offender registration
requirements and “shaming punishments of the colonial peri-
od.” Id. at 97. Historical shaming punishments were intended
to expose and publicly disgrace individuals, while sex
offender registration laws disseminate accurate information
about offenders for public safety purposes. Id. at 97-99. While
modern notification provisions may humiliate offenders, that
shame is “but a collateral consequence of a valid regulation.”
Id. at 99.

   Plaintiffs attempt to distinguish Smith on the grounds that,
unlike the Alaska law at issue there, AB 579 requires law
enforcement agencies actively to provide notice of an individ-
ual’s sex-offender status in many instances. See AB 579
§ 29(2). We have previously held that a state law which
included a provision requiring government agencies actively
to notify the public of certain individuals’ sex-offender status
was not so punitive in effect that it violated the Ex Post Facto
Clause. Russell, 124 F.3d at 1082, 1091-92. That logic
remains sound in the wake of Smith. Active dissemination of
an individual’s sex offender status does not alter the Court’s
core reasoning that “stigma . . . results not from public display
for ridicule and shaming but from the dissemination of accu-
1516                   ACLU v. MASTO
rate information about a criminal record, most of which is
already public.” Smith, 538 U.S. at 98. Though “humiliation
increas[es] in proportion to the extent of the publicity,” the
“purpose and the principal effect of notification are to inform
the public for its own safety.” Id. at 99.

   AB 579 also vests responsibility for disseminating informa-
tion to local law enforcement agencies, § 29(2), and strength-
ens penalties for use of information from the community
notification website to commit a crime, § 10.5. Both of these
provisions further indicate the law is intended to disseminate
information for public safety purposes and not to punish reg-
istrants. On the whole, the requirements of AB 579 are not
akin to historical forms of punishment.

       ii   Affirmative Disability or Restraint

   Under this factor, “we inquire how the effects of [AB 579]
are felt by those subject to it.” Smith, 538 U.S. at 99-100. The
“paradigmatic affirmative disability” is the “punishment of
imprisonment.” Id. at 100. The Smith Court found that Alas-
ka’s law imposed no physical restraint and therefore consti-
tuted a negligible affirmative disability. The Court reasoned
that any negative consequences to registrants’ employment or
housing prospects stemmed from the fact of conviction, rather
than the existence of the registry. Id. at 101.

   The registration and notification requirements of AB 579
are indistinguishable from those at issue in Smith. AB 579
imposes no physical restraint. See id. at 100. It does not limit
the activities that registrants may pursue or limit registrants’
ability to change jobs or residences. See id. It is less onerous
than occupational debarment, which the Court has held is not
an affirmative disability. See id.

   Plaintiffs focus on the fact that AB 579 requires registrants
to appear in person to update their registration information.
See AB 579 § 40. For the highest level offenders, this duty to
                       ACLU v. MASTO                       1517
appear is imposed “[n]ot less frequently than every 90 days.”
Id. § 40(c). Plaintiffs point out that in Smith, the Supreme
Court reversed our holding that Alaska’s law imposed an
affirmative disability, in part because we had mistakenly con-
cluded that it required in-person registration. See Smith, 538
U.S. at 101. However, the Court’s resolution of our factual
error did not amount to a holding that in person registration
necessarily constitutes an affirmative disability. We recog-
nized as much in Hatton, 356 F.3d at 964, where we held that
the in-person registration requirement in a California law,
when “balanced against the other facts . . . [was] simply not
enough to turn [the law at issue] into an affirmative disability
or restraint.”

   We reach the same conclusion with respect to AB 579.
While recognizing the burden that the registration require-
ment places on many registrants, on balance the law does not
constitute an affirmative disability. “Appearing in person may
be more inconvenient, but requiring it is not punitive.”
W.B.H., 2011 WL 6156956, at *8. The requirement that sex
offenders present themselves for fingerprinting is not akin to
imprisonment, and the burden remains less onerous than
occupational debarment. See Smith, 538 U.S. at 100.

       iii   Traditional Aims of Punishment

   This factor requires evaluating whether the law promotes
traditional aims of punishment — i.e., deterrence and retribu-
tion. Hatton, 356 F.3d at 965. The Smith Court acknowledged
that registration laws might have a deterrent effect, but held
that preventing recidivism is also a legitimate objective of
civil regulation. Smith, 538 U.S. at 102. The Court rejected
the argument that reporting requirements “measured by the
extent of the wrongdoing, not by the extent of the risk posed,”
demonstrated retributive intent. Id. (internal quotation marks
omitted). AB 579 is indistinguishable on this basis, and this
factor does not tilt toward a finding of punitive effect.
1518                     ACLU v. MASTO
       iv   Rational Connection to a Nonpunitive Purpose

   The Smith Court held that whether the challenged regula-
tion is rationally connected to a nonpunitive purpose is “a
most significant factor” in the effects analysis. Id. at 102
(internal quotation marks and alteration omitted). The Court
held that the interest in “alerting the public to the risk of sex
offenders in their community” constitutes a “legitimate non-
punitive purpose.” Id. at 102-103 (internal quotation marks
and alteration omitted).

   Plaintiffs argue that Smith overstated the risk of sex-
offender recidivism. They note that Smith cited several studies
on sex offender recidivism. See id. at 104. Plaintiffs then rely
on an expert declaration critiquing the methodology of the
recidivism studies in Smith. The district court did not make
any factual finding regarding the risk of sex offender recidi-
vism. Even had it adopted the declaration’s conclusions as its
own, a recalibrated assessment of recidivism risk would not
refute the legitimate public safety interest in monitoring sex-
offender presence in the community.

       v    Excessive in Scope

   In terms of the legislature’s tailoring of the law to the legit-
imate nonpunitive objective, the test is not “whether the legis-
lature has made the best choice possible,” but rather “whether
the regulatory means chosen are reasonable in light of the
nonpunitive objective.” Id. at 105. The Smith Court held that
Alaska could “mak[e] reasonable categorical judgments that
conviction of specified crimes should entail particular regula-
tory consequences.” Id. at 103. While AB 579 does expand
the size of the class subject to regulation, the linking of con-
viction status to registration is a reasonable nonpunitive regu-
latory scheme under Smith. Id.

  Plaintiffs’ argument that AB 579 is overbroad because it
will force many non-dangerous offenders to register is
                        ACLU v. MASTO                       1519
squarely foreclosed by Smith. “The State’s determination to
legislate with respect to convicted sex offenders as a class,
rather than require individual determination of their danger-
ousness, does not make the statute a punishment under the Ex
Post Facto Clause.” Id. at 104.

         vi & vii    Scienter and Application to Behavior
                    Already Criminalized

   The Smith Court concluded that two of the Mendoza-
Martinez factors — scienter and application of the law to
behavior which is already a crime — were of “little weight.”
Id. at 105. These two factors do not distinguish AB 579 from
the law at issue in Smith.

   As in Smith, AB 579 imposes registration requirements
only upon a criminal conviction, “a duty not predicated upon
some present or repeated violation.” Id. AB 579 exclusively
applies to behavior that is already criminalized under Nevada
law. However, as the Smith Court concluded, where “recidi-
vism is the statutory concern,” application to behavior already
criminalized is “a necessary beginning point.” Id.

   [5] Evaluating the Mendoza-Martinez factors together, we
conclude that AB 579 is not so punitive in effect or purpose
that it negates the Nevada legislature’s intent to enact a civil
regulatory scheme. AB 579 does not differ from the law at
issue in Smith in any fashion that alters the application of that
precedent. Plaintiffs’ evidence and arguments do not approach
the “clearest proof” of punitive purpose or effect required to
establish a violation of the Ex Post Facto Clause or Double
Jeopardy Clause.

    2.    Due Process

  The district court also enjoined AB 579 as a violation of the
Plaintiffs’ procedural due process rights under the Fourteenth
Amendment. Whether the law would amount to a violation of
1520                    ACLU v. MASTO
procedural due process rights also requires a two-step inquiry:
“the first asks whether there exists a liberty or property inter-
est which has been interfered with by the State; the second
examines whether the procedures attendant upon that depriva-
tion were constitutionally sufficient.” Ky. Dep’t of Corrs. v.
Thompson, 490 U.S. 454, 460 (1989) (internal citations omit-
ted).

   Following this framework, the first question is whether
Plaintiffs have a liberty interest in remaining free from the sex
offender registration and notification requirements of AB 579.
While stigma alone is inadequate to affect a liberty interest,
stigma plus an alteration in legal status can encroach on a
cognizable liberty interest. Paul v. Davis, 424 U.S. 693, 711-
12 (1976). We have previously held that prison inmates have
a liberty interest at stake in the determination of their status
as sex offenders. Neal v. Shimoda, 131 F.3d 818, 830 (9th Cir.
1997). In Neal, the liberty interest stemmed from the stigma-
tizing consequences of the sex offender label along with “the
subjection of the targeted inmate to a mandatory treatment
program whose successful completion is a precondition for
parole eligibility.” Id.

   [6] However, Smith v. Doe casts doubt on whether a regis-
tration and notification scheme based solely on the fact of a
registrant’s conviction entails stigmatizing consequences.
Smith acknowledged that the publication of an offender’s
identity may cause embarrassment, but held that “these conse-
quences flow not from the Act’s registration and dissemina-
tion provisions, but from the fact of conviction, already a
matter of public record.” Smith, 538 U.S. at 101. We need not
resolve this issue, however, “because even assuming,
arguendo, that [Plaintiffs have] been deprived of a liberty
interest, due process does not entitle [them] to a hearing.”
Conn. Dep’t of Pub. Safety v. Doe, 538 U.S. 1, 7 (2003).

   Connecticut Department of Public Safety controls our con-
sideration of whether AB 579 affords the Plaintiffs the pro-
                        ACLU v. MASTO                       1521
cess they are due. There, the Supreme Court held that sex
offenders were not entitled to a hearing on their dangerous-
ness under a Connecticut law that imposed registration
requirements based solely on the fact of conviction. Id. The
Court held that a hearing on an offender’s dangerousness was
a “bootless exercise” given that “the law’s requirements turn
on an offender’s conviction alone—a fact that a convicted
offender has already had a procedurally safeguarded opportu-
nity to contest.” Id. We have applied Connecticut Department
of Public Safety in a due process challenge to Alaska’s sex
offender law, holding that “[l]ike the Connecticut law, Alas-
ka’s sex offender statute bases the registration and notification
requirements on the sole fact of plaintiffs’ convictions.
Accordingly, bound by Connecticut Department of Public
Safety, we hold that Alaska’s sex offender registration law
does not deprive the Does of procedural due process.” Doe v.
Tandeske, 361 F.3d 594, 596 (9th Cir. 2004) (per curiam)
(holding that Alaska’s sex offender registration law does not
violate procedural or substantive due process).

   AB 579, like Connecticut and Alaska’s laws, imposes reg-
istration and notification requirements based solely on the fact
of conviction. Plaintiffs, however, attempt to distinguish Con-
necticut Department of Public Safety and Tandeske on the
ground that Plaintiffs are requesting a hearing to determine
whether or not they were in fact convicted, a factor — unlike
actual dangerousness — that is decidedly material under AB
579’s statutory scheme.

   [7] Plaintiffs’ argument is unavailing because the fact of
conviction is something “that a convicted offender has already
had a procedurally safeguarded opportunity to contest.” Con-
necticut Dep’t of Pub. Safety, 538 U.S. at 7. The Due Process
Clause does not entitle an individual to a hearing unless there
is “some factual dispute” that a hearing could serve to resolve.
Codd v. Velger, 429 U.S. 624, 627 (1977) (per curiam). A
hearing to ascertain each individual’s crime of conviction is
a “bootless exercise,” Connecticut Dep’t of Pub. Safety, 538
1522                   ACLU v. MASTO
U.S. at 7, because Nevada sex offenders have already had the
fact of their conviction established — with all of the constitu-
tionally required procedural safeguards — through the crimi-
nal justice system. “[A]dequate procedural safeguards at the
conviction stage are sufficient to obviate the need for any
additional process at the registration stage.” United States v.
Juvenile Male, __ F.3d __, 2012 WL 206263, at *13 (9th Cir.
2012).

   The cases cited by Plaintiffs do not support their claim
because, unlike AB 579, they all involved statutory schemes
which allowed the state to label an individual a sex offender
even if they had never been convicted of a sexual offense. See
Coleman v. Dretke, 395 F.3d 216, 223 n.30 (5th Cir. 2004)
(holding that individual was entitled to a hearing because he
had not had the “original procedurally safeguarded opportu-
nity to contest” a conviction for a sex offense (internal quota-
tion marks omitted)); State v. Robinson, 873 So. 2d 1205,
1216 n.8 (Fla. 2004) (“Unlike the defendant in Doe, Robinson
was not convicted of a crime involving a sexual element or
intent. Therefore, unlike that defendant, he did not have a
meaningful opportunity to contest whether his offense was
sexually related.”).

   Plaintiffs do accurately note that AB 579 expands the defi-
nition of sex offender to include “[a]n offense that is deter-
mined to be sexually motivated pursuant to NRS 175.547 or
207.193.” AB 579 § 8(r). However, Nevada law requires
nearly all of the fundamental protections of the criminal pro-
cess before a finding of sexual motivation can be made. See
Nev. Rev. Stat. §§ 175.547, 207.193 (requiring a judicial
hearing, the opportunity to present evidence, a “beyond a rea-
sonable doubt” standard of proof, and an on-the-record-
decision by the court). These procedural protections go well
beyond the minimum requirements of due process. All that is
potentially lacking is trial by jury, but a finding by a jury is
not required before the state may label an individual a sex
offender. Neal, 131 F.3d at 831 n.14 (Due Process Clause per-
                        ACLU v. MASTO                        1523
mits states to “flesh out” the “entity which should conduct
[the] hearing” that classifies a prisoner as a sex offender); see
also United States v. Sahhar, 917 F.2d 1197, 1203 n.6 (9th
Cir. 1990) (due process does not require jury trial in civil
commitment proceedings).

   [8] Under AB 579, offenders are required to register as sex
offenders only after they have been convicted of a sex offense
or found as the result of a judicial hearing to have committed
a sexually motivated crime, with all the attendant procedural
protections guaranteed by Nevada’s criminal justice system.
Because AB 579 imposes registration and notification
requirements solely on the basis of a fact established with
constitutionally adequate procedural protections, no additional
hearing is required under the Due Process Clause. Tandeske,
361 F.3d at 596.

    3.   Contract Clause

   At the conclusion of the September 10, 2008 hearing to
determine whether a permanent injunction was appropriate,
the court ordered the Plaintiffs to draft an order enjoining the
law on the basis of the Ex Post Facto Clause, the Double
Jeopardy Clause, the Equal Protection Clause, and the Due
Process Clause. The Plaintiffs then drafted an order that with-
out explanation includes a state and federal Contract Clause
rationale not previously mentioned by the court. Moreover,
the Order does not include any discernable legal rationale or
explanation for the added Contract Clause grounds. The
Clauses are mentioned in one sentence which simply appends
them, without any findings of fact or specific conclusions of
law, to a list of constitutional grounds justifying relief. Never-
theless, because the issue as presented is a matter of law, has
been fully briefed, and the record is sufficient to do so, we
proceed to a decision on this question.

  [9] We begin with the ACLU’s concession that “[t]he
Nevada Supreme Court has interpreted the State Constitu-
1524                   ACLU v. MASTO
tional Contracts Clause to be on a par with the U.S. Constitu-
tional Contracts Clause,” citing Holloway v. Barrett, 87 Nev.
385, 392 (1971). Thus, we turn to Article 1, § 10 of the fed-
eral Constitution, which states, “No State shall . . . pass any
. . . Law impairing the Obligation of Contracts.”

   U.S. Trust Co. v. New Jersey, 431 U.S. 1, 25 (1997), sup-
plies the approach we use in making this determination with
respect to public contracts. The factors are: (1) whether the
state law has the effect of impairing a contractual obligation;
(2) if so, whether that impairment is permitted under the Con-
stitution. In connection with the second question, the Court
observed that “it is not every modification of a contractual
promise that impairs the obligation of contract under federal
law.” U.S. Trust Co., 431 U.S. at 16 (quoting El Paso v. Sim-
mons, 379 U.S. 497, 506-07 (1965)). U.S. Trust Co. also reit-
erated that a “State has the sovereign right to protect the
general welfare of the people” and “we must respect the wide
discretion on the part of the legislature in determining what is
and what is not necessary.” Id. at 508-09 (internal quotation
marks and alternations omitted). The Court also has said that
the Contract Clause notwithstanding,

    [T]he state also continues to possess authority to
    safeguard the vital interests of its people. It does not
    matter that legislation appropriate to that end has the
    result of modifying or abrogating contracts already
    in effect. Not only are existing laws read into con-
    tracts in order to fix obligations as between the par-
    ties, but the reservation of essential attributes of
    sovereign power is also read into contracts as a pos-
    tulate of the legal order.

Home Bldg. & Loan Ass’n v. Blaisdell, 290 U.S. 398, 434-35
(1934) (internal citation omitted). Moreover, U.S. Trust Co.
reminds us that “States must possess broad power to adopt
general regulatory measures without being concerned that pri-
                         ACLU v. MASTO                        1525
vate contracts will be impaired, or even destroyed, as a
result.” U.S. Trust Co., 431 U.S. at 22.

   [10] With this controlling backdrop in mind, we conclude
at the threshold that AB 579 on its face does not perforce
impair the plea bargain contracts of those who fall within its
scope. As we have already held in our disposition of the
Plaintiffs’ ex post facto, double jeopardy, and due process
challenges, (1) the law is not punitive in intent, (2) it has no
overriding punitive effect, (3) it is not the equivalent of histor-
ical punishment, (4) and it does not impose upon a registrant
any significant affirmative disability or restraint. Moreover,
AB 579 has a rational connection to a nonpunitive regulatory
purpose and is not excessive in scope. Finally, the law
respects the due process rights of those upon whom its
requirements fall. Tandeske, 361 F.3d 596-97 (holding that
Alaska’s sex offender registration law did not violate proce-
dural or substantive due process).

   Were we to conclude that AB 579 does impair plea bargain
contracts, which we do not, we would nevertheless conclude
that the impairment is permitted under the Constitution. We
would do so for the same reasons previously articulated and
because of the importance of this law to the protection of the
general welfare of people in Nevada against sexually moti-
vated crimes. Nevada’s police power to promote public safety
is entitled to respect. A State’s law in this context is entitled
to a presumption of constitutionality. Smith, 528 U.S. at 110
(Thomas, J., concurring).

   However, we do note that in individual cases where the
state has made an explicit promise to a defendant that the
defendant would be exempt from registration as a condition
of his guilty plea, that promise — whether memorialized in
the terms of the written plea agreement or otherwise proven
— is entitled to be enforced against the State. Santobello v.
New York, 404 U.S. 257, 262 (1971) (“[W]hen a plea rests in
any significant degree on a promise or agreement of the pros-
1526                         ACLU v. MASTO
ecutor, so that it can be said to be part of the inducement or
consideration, such promise must be fulfilled.”); see also
Buckley v. Terhune, 441 F.3d 688, 694 (9th Cir. 2006) (en banc).5

B.     Senate Bill 471

   Under Article III of the Constitution, federal “courts may
adjudicate only actual, ongoing cases or controversies.” Lewis
v. Cont’l Bank Corp., 494 U.S. 472, 477 (1990). A live con-
troversy requires an injury in fact, traceable to the defendant’s
acts and redressable by a court decision. Lujan v. Defenders
of Wildlife, 504 U.S. 555, 560-561 (1992). The case or contro-
versy must continue through all stages of federal judicial pro-
ceedings. United States v. Juvenile Male, ___ U.S. ___, 131
S. Ct. 2860, 2864 (2011) (per curiam). When the possibility
of injury to the plaintiffs ceases, the case is rendered moot and
we lack jurisdiction to decide it. Rosemere Neighborhood
Ass’n v. EPA, 581 F.3d 1169, 1172-73 (9th Cir. 2009). Even
if the parties do not raise mootness as an issue, “federal courts
are required sua sponte to examine jurisdictional issues.” B.C.
v. Plumas Unified Sch. Dist., 192 F.3d 1260, 1264 (9th Cir.
1999).

   Under the unusual circumstances of this case, we conclude
that the question of the constitutionality of retroactive applica-
tion to Plaintiffs of the residency and movement restrictions
of SB 471 may well have been mooted. The State’s candid
and forthright admission during oral argument that, regardless
  5
    In Doe v. Harris, 640 F.3d 972 (9th Cir. 2011), the Supreme Court of
California accepted our request to decide whether “under California law,
the default rule of contract interpretation is (a) that the law in effect at the
time of a plea agreement binds the parties, or (b) that the terms of a plea
agreement may be affected by changes in law.” A decision by that court
on this issue has not been rendered. We do note as a matter of Nevada
state law that a condition of lifetime supervision as a consequence of
pleading guilty to a qualifying crime cannot be imposed by a court unless
a defendant so pleading is advised of this consequence. Palmer v. State,
118 Nev. 823 (2002).
                       ACLU v. MASTO                       1527
of the outcome of this case, the State does not intend to apply
the contested provisions of SB 471 retroactively removes any
threat that Plaintiffs or anyone similarly situated will be sub-
ject to any deleterious effect or injury from the statute.

   Until oral argument, it remained an open question whether
the relevant provisions of SB 471 could be applied retroac-
tively. The confusion arose because the relevant provisions of
SB 471 are ambiguous as to whether they are to be applied to
those whose crimes were committed before October 1, 2007,
the law’s effective date. For instance, SB 471 states that “if
a defendant is convicted of a sexual offense and the court
grants probation or suspends the sentence, the court shall”
impose the new residency and movement restrictions, depend-
ing on the classification of the offender, “as a condition of
probation or suspension of a sentence.” SB 471 § 2(1). But it
is not clear whether these new conditions are to be applied
retroactively to all offenders granted probation after October
1, 2007, regardless of when the defendant committed his
offense, or only to those whose crimes were actually commit-
ted following the law’s effective date. By contrast, AB 579 is
explicit that its registration requirements apply retroactively.
For purposes of the registration requirements, a “sex offend-
er” is “a person who, after July 1, 1956, is or has been (a)
convicted of a sexual offense . . .” A.B. 579 § 20 (emphasis
added).

  A law applies “retroactively” for purposes of the Ex Post
Facto Clause if it “changes the punishment, and inflicts a
greater punishment, than the law annexed to the crime, when
committed.” Collins v. Youngblood, 497 U.S. 37, 42 (1990)
(quoting Calder v. Bull, 3 U.S. (3 Dall.) 386, 390 (1798))
(emphasis added; emphases in original removed). This is the
sense in which we use “retroactive” and “retroactively,”
regardless of the date when probation was granted or revised.

   Before the district court, the State repeatedly maintained
that it did not interpret the disputed sections of SB 471 as
1528                   ACLU v. MASTO
applying retroactively. The State said, “Based upon the plain
reading of the statutes at issue . . . they are prospective in
application.” Plaintiffs, however, protested that they had
“been unable to get clarity from the AG’s office on exactly
which portions of SB 471 would be applied retroactively and
which won’t.” They submitted communications with the
Attorney General’s Office demonstrating that the State had
shifted its position several times. The ACLU captured this
state of uncertainty in a letter from Maggie McLetchie to
Deputy Attorney General Binu Palal dated July 3, 2008:

       As you know, the ACLU reached out to your
    offices in June, before filing suit, in the hopes of
    negotiating a temporary stay so that we could resolve
    those issues with the law where there is no question
    that the law is unconstitutional on its face, or being
    applied unconstitutionally. We also hoped that we
    could get some much needed clarity as to the State
    of Nevada’s interpretation of both AB579 and
    SB471. Unfortunately, your office was unwilling to
    consider any stipulated stay whatsoever and we had
    no choice but to research and file both a complaint
    and a motion for a temporary restraining
    order/preliminary injunction motion addressing a
    myriad of issues with the new sex offender laws.

       While we are now in litigation, it is our hope that
    we can nonetheless work together to get some clarity
    as to the State of Nevada’s interpretation of the laws
    and how state agencies have planned to implement
    them. For example, if we could come to an agree-
    ment that SB 471 will not be applied retroactively,
    and to whom it will apply, that could greatly help
    streamline the very-expedited litigation we are now
    engaged in, and save the ACLU from expending
    unnecessary additional resources litigating that
    issue.
                       ACLU v. MASTO                          1529
       Last Monday, June 30, I reached out to you in
    advance of the hearing to try to get an answer as to
    the Attorney General’s official position on whether
    SB471 would or would not apply SB471 [sic] retro-
    actively. While initially you stated that “[t]he Office
    of Parole and Probation’s position is that the resi-
    dency and movement requirements of SB 471 do not
    apply retroactively” and that “[your] representation
    of that office will reflect that position,” you later
    retracted and indicated that your response was “pre-
    mature” and that “[t]he AG’s Office has not issued
    a formal opinion on this.” I did not hear further from
    you, so I again reached out to you yesterday to get
    an answer on this issue but I have yet to receive any
    confirmation as to the Attorney General’s formal
    position.

    ....

       So that we can resolve that confusion without
    expending any additional legal resources of either
    the ACLU or the taxpayer-funded budgets of the
    defendants, please provide confirmation as to the
    Attorney General’s position on SB471 no later than
    the close of business (5 p.m.) today. Please feel free
    to call me to discuss the matter. I look forward to
    hearing from you.

(emphasis added).

   Mr. Palal’s timely answer the same day was, “At this time,
the Office of the Attorney General has not taken a position as
to the retroactivity of the numerous provisions contained in
SB 471.”

   Thirteen days later, on July 16, 2008, Mr. Palal wrote to
Ms. McLetchie again, this time stating that, “It is the position
of this office that the mechanism provided to employ the pro-
1530                       ACLU v. MASTO
visions of SB 471 only allows for prospective application.
Therefore, the position of this office is that the statutes stem-
ming from SB 471 will be applied prospectively.” However,
the next day, Mr. Palal in another letter appeared to take a
step back from this position, this time stating that the only
provision of SB 471 that did not apply retroactively was its
“requirements concerning residency within 1000 feet of a
school or daycare facility.”

   All of this back and forth notwithstanding, the ACLU rep-
resented to the court in August 2008 that “Defendants have
finally conceded that S.B. 471 cannot be applied retroactive-
ly,” and they dismissed certain claims because, “Now, . . . SB
471 will no longer be applied retroactively.” However, the
ACLU understandably asked for a formal court order to this
effect citing inter alia 28 U.S.C. § 2201(a) regarding a binding
declaration of rights.

   In the district court, Plaintiffs introduced affidavits from
several Doe plaintiffs, all of whom were convicted well
before the law’s effective date, indicating that they had been
notified by their parole officers that they would be required to
comply with SB 471’s residency restrictions. The State did
not introduce any contrary evidence and opposed discovery in
the case. With the case in that posture, the district court
appropriately recognized that the retroactive application of SB
471 was an unresolved justiciable controversy, Mr. Palal’s let-
ter of July 16 notwithstanding.6

   In its briefing before us, the State maintains that SB 471’s
residency and movement restrictions, as a matter of its inter-
pretation of the statutory language, cannot apply retroactively.
In its reply brief, for example, the State advised us that “life-
time supervision residency requirements, parole, and proba-
  6
    The State never packaged its interpretation of SB 471 as an issue of
justiciability. It made the argument in response to a vagueness challenge
not at issue here.
                        ACLU v. MASTO                           1531
tion terms found in SB 471 all specifically call for a
contemporaneous order from the [sentencing] court and can-
not be employed retroactively.” The State also represented
that it had “throughout litigation maintained that SB 471, in
its relevant pieces, is prospective and not retroactive.” How-
ever, the State has not raised mootness as an issue.

   During oral argument, the State acknowledged that Plain-
tiffs introduced evidence that Nevada probation and parole
officers may have represented to probationers and parolees
that SB 471 would apply retroactively to them. In a formal
colloquy with the court, the State conceded that any attempt
by state parole officers to apply the residency and movement
restrictions retroactively was an error in State oversight and
that in the future there was no possibility that the restrictions
would be applied retroactively. The culmination of the
exchange was the State’s response to the court’s question:

    The court:    Well, would you agree to represent to
                  this court that if the parole officers said
                  that [Plaintiffs were required to comply
                  with SB 471’s residency and movement
                  conditions], the State in that event apol-
                  ogizes to clients of the ACLU and
                  undertakes to never have that happen
                  again?

    The State:    Absolutely.

   Normally a state Attorney General’s interpretation of state
law, advanced during the course of litigation, is not authorita-
tive and would not be sufficient to moot a live case or contro-
versy. See Stenberg v. Carhart, 530 U.S. 914, 940 (2000); see
also Tahoe Reg’l Planning Agency v. McKay, 769 F.2d 534,
539 (9th Cir. 1985) (Nevada Attorney General’s interpretation
of state law does not bind state courts). As recognized by the
district court, a state Attorney General is generally free to
advance an interpretation of a statute during litigation that a
1532                     ACLU v. MASTO
subsequently appointed Attorney General may choose to dis-
avow. And like any litigant, a state Attorney General may
make a tactical choice to present two conflicting positions as
an argument in the alternative.

   [11] Nevada’s statement in this case, however, constitutes
a binding judicial admission because the State went beyond a
simple expression of its legal position regarding the interpre-
tation of SB 471. The State represented, as a matter of law,
that it had no authority under SB 471 to apply its movement
and residency restrictions retroactively and that it will “abso-
lutely” not do so in the future. See United States v. Wilmer,
799 F.2d 495, 502 (9th Cir. 1986) (representation at oral argu-
ment is judicial admission). A litigation position such as this
conveyed to a court becomes binding in any forum in which
the same controversy arises. New Hampshire v. Maine, 532
U.S. 742 (2001) (the doctrine of judicial estoppel prohibits a
party from “changing positions according to the exigencies of
the moment” (internal quotation marks omitted)); Helfand v.
Gerson, 105 F.3d 530 (9th Cir. 1997) (a party taking a posi-
tion in litigation precludes that party from later assuming an
inconsistent position on the same issue). The State, like any
party, is responsible for official representations that it makes
to the court. United States v. Crawford, 372 F.3d 1048, 1055
(9th Cir. 2004) (en banc) (“A judicial admission is binding
before both trial and appellate courts.”). The State’s judicial
admission that the residency and movement restrictions of SB
471 “ought not [be] and are not” being applied retroactively
is therefore binding. This judicial admission appears to moot
the issue that was argued before us: whether retroactive appli-
cation of SB 471’s residency and movement restrictions could
constitutionally be applied retroactively.

   [12] In fine, the State’s clarification of its official position
on this statute removes any potential of deleterious effect or
injury to Plaintiffs and divests us of a live case or controversy.
As Judge Wood said in United States v. Leach, 639 F.3d 769,
773 (7th Cir. 2011), “Because the law targets only the conduct
                       ACLU v. MASTO                       1533
undertaken by convicted sex offenders after its enactment, it
does not violate the Ex Post Facto Clause.” (citing Weaver v.
Graham, 450 U.S. 24, 29 (1981)). We do note that the State
limited its concession to the residency and movement restric-
tions of SB 471, saying that “Nevada, in interpreting its own
laws, concluded that movement and residency restrictions
contained SB 571 [sic] cannot be applied retroactively.” We
will hold the State to its categorical representation.

   The “normal rule” when a case is mooted is that vacatur of
the lower court decision is appropriate. Camreta v. Greene,
__U.S.__, 131 S. Ct. 2020, 2035 (2011). That is the default
approach because it “prevent[s] a judgment, unreviewable
because of mootness, from spawning any legal conse-
quences.” United States v. Munsingwear, Inc., 340 U.S. 36,
41 (1950).

   There is an exception to the Munsingwear rule, however,
when the “party seeking relief from the judgment below
caused the mootness by voluntary action.” U.S. Bancorp
Mortg. Co. v. Bonner Mall P’ship, 513 U.S. 18, 24 (1994);
see also Ringsby Truck Lines, Inc. v. Western Conference of
Teamsters, 686 F.2d 720, 722 (9th Cir. 1982) (recognizing
exception to automatic vacatur “when the appellant has by his
own act caused the dismissal of the appeal”). In U.S. Bancorp,
the appellant had voluntarily mooted the issue on appeal
through entering into a settlement. Id. at 20. The Supreme
Court held that when appealing parties voluntarily forfeit their
right to appeal and receive a decision on the merits, they also
surrender their claim to “the equitable remedy of vacatur.” Id.
at 25. In those circumstances, the court “ ‘may not consider
[the] merits, but may make such disposition of the whole case
as justice may require.’ ” Id. at 21 (quoting Walling v. James
V. Reuter, Co., Inc., 321 U.S. 671, 677 (1944).

  The U.S. Bancorp exception applies in this case. The State
appealed the permanent injunction placed on retroactive
application of SB 471, but then unilaterally bound itself
1534                    ACLU v. MASTO
through a judicial admission that mooted the controversy as
to retroactive application now before this court. As in U.S.
Bancorp, the live case was resolved by the strategic decision
of the appealing party rather than mere happenstance. See id.
Accordingly, because “the party seeking relief from the judg-
ment below caused the mootness by voluntary action” we
retain the authority to dispose of the case in the manner “most
consonant to justice.” Id. at 24 (internal quotation marks omit-
ted).

  When a case has been mooted by the appellant’s own
actions, the Supreme Court has directed that appellate courts
should vacate the district court order only in “exceptional cir-
cumstances.” Id. at 29. Our “established procedure” is to
remand to the district court so it may balance the relevant
equitable concerns and decide whether to vacate its judgment.
Dilley v. Gunn, 64 F.3d 1365, 1370 (9th Cir. 1995).

   In this case, we conclude that Nevada’s concession regard-
ing the application of SB 471’s disputed provisions, both
facially and as applied, would most appropriately be captured
in a binding and enforceable comprehensive consent decree
fashioned by the parties with the approval of the court and
covering all agencies responsible for enforcing SB 471 and all
the relevant provisions of the law. This result is precisely
what the ACLU requested from the Attorney General in its
letter of July 3, 2008 and would eliminate the district court’s
concerns about a subsequent administration changing its posi-
tion. We note that several defendants were dismissed from the
case based on the stipulation that they would abide by the
decision of the district court. Moreover, our suggested resolu-
tion, which eliminates the Contract Clause challenge, is con-
sistent with the prudential rule that we should avoid deciding
a constitutional issue unless necessary to resolve a contro-
versy. Lyng v. Northwest Indian Cemetery Protective Assn.,
485 U.S. 439, 445 (1988) (“A fundamental and longstanding
principle of judicial restraint requires that courts avoid reach-
                        ACLU v. MASTO                        1535
ing constitutional questions in advance of the necessity of
deciding them.”).

   [13] Accordingly, trusting that the litigants will work
together to fashion appropriate relief, and in view of the
State’s stated position that SB 471 will not be applied retroac-
tively, we dismiss as moot the State’s appeal of the district
court’s ruling on SB 471. Therefore, the injunction against
retroactive application of SB 471, for the time being, remains
in effect. We remand to the district court for further proceed-
ings consistent with Nevada’s representation regarding SB
471

C.   Stay on Payment of Attorneys’ Fees

   The State separately appeals the district court’s denial of its
request for a stay on payment of attorneys’ fees pending
appeal under Federal Rule of Civil Procedure 62(d). Had the
State complied with the express requirements of Rule 62(d)
by appealing the underlying fees order and posting a superse-
deas bond with the district court, it would have been entitled
to a stay as a matter of right. In re Combined Metals Reduc-
tion Co., 557 F.2d at 193. But the State did not appeal the fees
order or post a supersedeas bond, and therefore “the grant or
denial of the stay[ ] was a matter strictly within the judge’s
discretion.” Id.

   [14] The State fails to identify any instance in which the
court supposedly abused its discretion. The judge justified his
denial based on the State’s failure to comply with the express
requirements of Rule 62(d). The court properly exercised its
discretion in doing so. See, e.g., Cervantes v. Countrywide
Home Loans, Inc., 656 F.3d 1034, 1043 (9th Cir. 2011)
(party’s failure to comply with procedural rules sufficient
grounds for court’s exercise of discretion denying their
motion).
1536                   ACLU v. MASTO
                              IV

                      CONCLUSION

   [15] We reverse the district court with respect to the
injunction placed on retroactive application of AB 579. With
respect to SB 471, we dismiss the appeal as moot in view of
the State’s representation that it will not apply retroactively
the relevant provisions of SB 471, and we remand to the dis-
trict court to consider whether to vacate the injunction order
and to replace it with a binding consent decree. We affirm the
district court’s order denying a stay on payment of attorney’s
fees.

   Appeal No. 08-17471 is REVERSED in part, DISMISSED
AS MOOT in part, and REMANDED. Each party shall bear
its own costs. Appeal No. 09-16008 is AFFIRMED.
