                     FOR PUBLICATION

    UNITED STATES COURT OF APPEALS
         FOR THE NINTH CIRCUIT


 UNITED STATES OF AMERICA,                       No. 10-30072
             Plaintiff-Appellee,
                                                  D.C. No.
                   v.                       1:09-cr-00023-JDS-1

 MARK STEVEN ELK SHOULDER,                      ORDER AND
          Defendant-Appellant.                   OPINION


       Appeal from the United States District Court
               for the District of Montana
    Jack D. Shanstrom, Senior District Judge, Presiding

                 Submitted June 1, 2012*
                     Portland, Oregon
              Opinion filed: October 4, 2012
         Opinion withdrawn and new Opinion filed:
                   September 23, 2013

         Before: A. Wallace Tashima, Carlos T. Bea,
            and Sandra S. Ikuta, Circuit Judges.

                            Order;
                     Opinion by Judge Ikuta




  *
    The panel unanimously concludes this case is suitable for decision
without oral argument. See Fed. R. App. P. 34(a)(2).
2              UNITED STATES V. ELK SHOULDER

                           SUMMARY**


                           Criminal Law

    The panel withdrew an opinion filed October 5, 2012, and
filed a superseding opinion affirming a judgment in a case in
which the defendant was convicted of failing to comply with
the registration requirements set forth in the Sex Offender
Registration and Notification Act.

    The panel rejected, as foreclosed by United States v.
Elkins, 683 F.3d 1039 (9th Cir. 2012), the defendant’s
argument that application of the SORNA registration
requirements to him on the basis of his earlier conviction
violates the Ex Post Facto Clause.

    The panel rejected as foreclosed by Elkins the defendant’s
due-process argument that because Montana had not yet
conformed its sex offense registration to SORNA’s
requirements, it was impossible for him to register “as
required by” SORNA. The panel also held that because the
defendant received notice of his obligation to register under
Montana law, he received all the notice the Due Process
Clause requires.

   Under the reasoning of United States v. Kebodeaux,
133 S. Ct. 2496 (2013), the panel rejected the defendant’s
argument that Congress lacked the authority under the
Property Clause and Necessary and Proper Clause to apply
SORNA to him. In so holding, the panel reasoned: (1) the

  **
     This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
            UNITED STATES V. ELK SHOULDER                  3

defendant was subject to the Wetterling Act’s registration
requirements upon his release from prison in May 2008
through August 1, 2008, when SORNA became applicable to
him, and his release from federal custody was therefore not
unconditional; and (2) because 42 U.S.C. § 14072(i)(2)
applied to pre-Act offenders such as the defendant
prospectively, not retrospectively, the Wetterling Act’s
imposition of criminal penalties on individuals who violate
the applicable registration requirements does not violate the
Ex Post Facto Clause.

    The order stated that the parties may file an additional
petition for rehearing or rehearing en banc.


                        COUNSEL

Lisa J. Bazant, Billings, Montana, for Appellant.

Michael W. Cotter, United States Attorney, J. Bishop Grewell
and Marcia Hurd, Assistant United States Attorneys, Billings,
Montana, for Appellee.


                         ORDER

    The opinion filed on October 5, 2012, and appearing at
696 F.3d 922 is withdrawn. The superseding opinion will be
filed concurrently with this order. The parties may file an
additional petition for rehearing or rehearing en banc.
4            UNITED STATES V. ELK SHOULDER

                         OPINION

IKUTA, Circuit Judge:

    This appeal challenges the constitutionality of certain key
provisions of the Sex Offender Registration and Notification
Act (SORNA). Pub. L. 109-248, §§ 101–55, 120 Stat. 587,
590–611 (codified in scattered sections of U.S.C. (2006)).
Defendant Mark Steven Elk Shoulder was prosecuted under
18 U.S.C. § 2250(a) for failing to comply with the sex
offender registration requirements set forth in 42 U.S.C.
§ 16913. He now argues that his conviction was invalid,
because SORNA violates the Ex Post Facto Clause and the
Due Process Clause, and because Congress lacked the
constitutional authority to enact SORNA. We reject these
constitutional challenges and affirm the judgment of the
district court.

                               I

    The history of Congress’s activities in ensuring the
registration of sex offenders provides the backdrop to the
facts of this case.

                              A

    In 1994, Congress enacted the Jacob Wetterling Crimes
Against Children and Sexually Violent Offender Registration
Act (“Wetterling Act”), Pub. L. No. 103-322,
§§ 170101–170303, 108 Stat. 1796, 2038–45 (1994), the first
federal act addressing sex offender registration. The
Wetterling Act served at least two functions. First, it “used
the federal spending power to encourage States to adopt sex
offender registration laws.” United States v. Kebodeaux,
             UNITED STATES V. ELK SHOULDER                    5

133 S. Ct. 2496, 2501 (2013) (citing 42 U.S.C. § 14071(i)
(2000 ed.)). Specifically, 42 U.S.C. § 14071(a) required the
Attorney General to “establish guidelines for State programs”
requiring people “convicted of a criminal offense against a
[minor] victim,” or “a sexually violent offense,” to register a
current address for a specified time period. Although the Act
did not require states accepting funds to impose this
registration requirement retroactively on individuals
previously convicted of sex offenses, the Act did “not
preclude states from imposing any new registration
requirements on offenders convicted prior to the
establishment of the registration system.” Final Guidelines
for Megan’s Law and the Jacob Wetterling Crimes Against
Children and Sexually Violent Offender Registration Act,
62 Fed. Reg. 39,009, 39,013 (July 21, 1997).

    Second, the Wetterling Act “imposed federal penalties
upon federal sex offenders who failed to register in the States
in which they lived, worked, and studied.” Kebodeaux,
133 S. Ct. at 2501 (citing 42 U.S.C §§ 14072(i)(3)–(4)).
Relevant here, § 14702(i)(2) provided that a person who is
“required to register under a sexual offender registration
program in the person’s State of residence and knowingly
fails to register in any other State in which the person is
employed, carries on a vocation, or is a student,” is subject to
specified penalties. Similarly, § 14702(i)(3) imposed a
penalty on a person who is “described in section 4042(c)(4)
of title 18 [specifying various sex offenses], and knowingly
fails to register in any State in which the person resides, is
employed, carries on a vocation, or is a student following
release from prison or sentencing to probation.”

   “[B]y 2000, all fifty states and the District of Columbia
had both sex offender registration systems and community
6            UNITED STATES V. ELK SHOULDER

notification programs.” United States v. Crowder, 656 F.3d
870, 872 (9th Cir. 2011) (alteration in original) (internal
quotation marks omitted). Montana, the state where Elk
Shoulder resided, first enacted a Sexual Offender Registration
Act in 1989, even before the Wetterling Act was passed.
State v. Villanueva, 118 P.3d 179, 181 (Mont. 2005)
(explaining that Montana’s sex offender registry applied to
“sexual offenders who are sentenced by a state or federal
court in any state on or after July 1, 1989, or who as a result
of a sentence are under the supervision of a county, state, or
federal agency in any state on or after July 1, 1989” (internal
quotation marks omitted)). Though Montana’s act has been
amended several times, Elk Shoulder does not dispute its
continued applicability to him.

    Although most states complied with the Wetterling Act’s
encouragement to enact sex-offender registration, pre-
SORNA registration laws consisted of a “patchwork of
federal and 50 individual state registration systems.”
Reynolds v. United States, 132 S. Ct. 975, 978 (2012) (citing
73 Fed. Reg. 38,045 (2008)). To address this problem, in
2006, Congress enacted SORNA “to succeed and enhance the
registration requirements of the Wetterling Act.” United
States v. Begay, 622 F.3d 1187, 1190 (9th Cir. 2010).

    SORNA is designed to improve the uniformity and
effectiveness of sex-offender registration systems by, among
other things, “creating federal criminal sanctions applicable
to those who violate the Act’s registration requirements.”
Reynolds, 132 S. Ct. at 978. SORNA’s registration
requirement, codified at 42 U.S.C. § 16913, requires all state
                UNITED STATES V. ELK SHOULDER                         7

and federal sex offenders,1 to “register, and keep the
registration current, in each jurisdiction where the offender”
resides, works, or goes to school.2 A person who fails to
register as required by § 16913 may be criminally prosecuted
under 18 U.S.C. § 2250(a). This provision requires the
government to prove that the defendant: (1) is required to
register under SORNA, (2) is a “sex offender” due to a
conviction under federal law (or the law of certain other listed
jurisdictions) or a person who “travels in interstate or foreign
commerce, or enters or leaves, or resides in, Indian country”
and, (3) knowingly failed to register or update a registration
as required by SORNA.3

 1
   42 U.S.C. § 16911(1) defines “sex offender” to “mean[ ] an individual
who was convicted of a sex offense.” The term “sex offense” is defined
in § 16911(5)(A)(i) to include: “a criminal offense that has an element
involving a sexual act or sexual contact with another.”
 2
     42 U.S.C. § 16913(a) provides:

          A sex offender shall register, and keep the registration
          current, in each jurisdiction where the offender resides,
          where the offender is an employee, and where the
          offender is a student. For initial registration purposes
          only, a sex offender shall also register in the
          jurisdiction in which convicted if such jurisdiction is
          different from the jurisdiction of residence.
 3
     18 U.S.C. § 2250(a) states:

          (a) In General.— Whoever—

               (1) is required to register under the Sex Offender
               Registration and Notification Act;

               (2) (A) is a sex offender as defined for the
                   purposes of the Sex Offender Registration and
                   Notification Act by reason of a conviction
8            UNITED STATES V. ELK SHOULDER

    Although SORNA imposed various requirements on sex
offenders, it did not provide that its registration requirements
would apply retroactively to sex offenders convicted before
July 27, 2006, SORNA’s effective date. United States v.
Valverde, 628 F.3d 1159, 1162 (9th Cir. 2010). Instead, it
gave the Attorney General the authority to enact regulations
specifying the applicability of SORNA’s registration
requirements to pre-Act offenders. Id. (citing 42 U.S.C.
§ 16913(d)). In Valverde, we held that the Attorney General
did not complete the steps necessary to make SORNA
retroactive until August 1, 2008. Id. at 1169. Therefore, the
requirements of SORNA became applicable to pre-Act
offenders on that date. Id. The Wetterling Act, however,
remained in effect until repealed by SORNA, effective on the
later of July 27, 2009, or one year after the software required
by SORNA became available. Pub. L. 109-248, §§ 129(b),
124, 120 Stat. at 600–01, 598.




                under Federal law (including the Uniform
                Code of Military Justice), the law of the
                District of Columbia, Indian tribal law, or the
                law of any territory or possession of the
                United States; or

                (B) travels in interstate or foreign commerce,
                or enters or leaves, or resides in, Indian
                country; and

           (3) knowingly fails to register or update a
           registration as required by the Sex Offender
           Registration and Notification Act;

       shall be fined under this title or imprisoned not more
       than 10 years, or both.
                UNITED STATES V. ELK SHOULDER                          9

                                     B

    In 1992, before Congress passed the Wetterling Act but
after Montana had enacted its registration requirements, Elk
Shoulder was convicted in a federal district court in Montana
of sexual abuse of a six-year-old child in violation of
section 2241(c) of Title 18 of the United States Code.4 In
1992, the court sentenced Elk Shoulder to 172 months in
prison, followed by five years supervised release. Upon his
release in December 2003, officials informed Elk Shoulder
that he was required to register as a sex offender under
Montana law. He registered in Yellowstone County,
Montana, where he signed and initialed the state’s “Sexual
and Violent Offender Registration Form.” By doing so, Elk
Shoulder acknowledged that state law required him to
maintain a current and updated registration, and that his duty
to register would continue for the rest of his life, even after
the expiration of probation or parole.

    Weeks later, in February 2004, Elk Shoulder was
sentenced to thirty months in prison, to be followed by thirty
months of supervised release, for violating the terms of his
supervised release. Upon Elk Shoulder’s second release from
prison, in April 2006, he again registered as a sex offender in
Yellowstone County. Congress enacted SORNA on July 26,
2006, but because Elk Shoulder was a pre-Act offender,

 4
     At the time of Elk Shoulder’s conviction, § 2241(c) provided:

          Whoever, in the special maritime and territorial
          jurisdiction of the United States or in a Federal prison,
          knowingly engages in a sexual act with another person
          who has not attained the age of 12 years, or attempts to
          do so, shall be fined under this title, imprisoned for any
          term of years or life, or both.
10           UNITED STATES V. ELK SHOULDER

SORNA did not yet apply retroactively to him. See Valverde,
628 F.3d at 1169. In August 2006, Elk Shoulder again
violated the terms of his supervised release and was
sentenced to another twenty-four months in prison.

     Elk Shoulder was released a third time in May 2008. Two
months later, on August 1, 2008, SORNA became applicable
to pre-Act offenders, including Elk Shoulder. See id. After
his third release, Elk Shoulder moved around Montana, living
at various times in the Northern Cheyenne Indian
Reservation, Bozeman, Lame Deer, Billings, and Wolf Point.
He did not register as a sex offender in any of these locales.

    On February 23, 2009, Elk Shoulder was indicted under
18 U.S.C. § 2250(a) for violating the SORNA registration
requirements in 42 U.S.C. § 16913. Before trial, Elk
Shoulder brought two motions to dismiss the indictment. In
the first, he asserted that SORNA’s registration provision
exceeded Congress’s authority under the Commerce Clause.
In the second, he claimed that the retroactive application of
these provisions violated the Ex Post Facto Clause. The
district court denied both motions. After a bench trial, the
court found Elk Shoulder guilty beyond a reasonable doubt.
He was sentenced to a term of thirty months’ imprisonment,
to be followed by five years’ supervised release.

    On appeal, Elk Shoulder argues that the district court
erred in rejecting his constitutional challenges to SORNA.
We initially affirmed the district court in an opinion issued on
October 5, 2012. But on January 11, 2013, before our
opinion became final, the Supreme Court granted certiorari in
United States v. Kebodeaux, 687 F.3d 232 (5th Cir. 2012) (en
banc), cert. granted, 133 S. Ct. 928 (2013), a Fifth Circuit
case holding that the Necessary and Proper Clause did not
             UNITED STATES V. ELK SHOULDER                   11

permit Congress to require sex offenders who had been
“unconditionally released” from federal custody to register
under SORNA. Id. at 244–45. Because Elk Shoulder’s
challenge implicated the Necessary and Proper Clause, we
stayed the mandate in this case pending the Supreme Court’s
decision. On June 24, 2013, the Supreme Court reversed the
Fifth Circuit. Kebodeaux, 133 S. Ct. at 2500. We
subsequently ordered supplemental briefing, asking the
parties to address the impact of Kebodeaux on Elk Shoulder’s
case. Having reviewed the parties’ supplemental briefs, we
now address all of Elk Shoulder’s claims.

                               II

    We first consider Elk Shoulder’s argument that SORNA’s
statutory scheme for requiring sex offenders to register and
criminalizing certain failures to register violates the Ex Post
Facto Clause.

    The Constitution provides: “No . . . ex post facto Law
shall be passed.” U.S. Const. art. I, § 9, cl. 3. As the
Supreme Court has succinctly explained, “[l]egislatures may
not retroactively alter the definition of crimes or increase the
punishment for criminal acts.” Collins v. Youngblood,
497 U.S. 37, 43 (1990); see also United States v. Elkins,
683 F.3d 1039, 1044 (9th Cir. 2012) (holding that the Ex Post
Facto Clause “bars the enactment of any law that ‘imposes a
punishment for an act which was not punishable at the time
it was committed; or imposes additional punishment to that
then prescribed.’” (quoting Russell v. Gregoire, 124 F.3d
1079, 1083 (9th Cir. 1997)).

   Elk Shoulder asserts that SORNA’s registration
requirement constitutes an additional punishment for his
12           UNITED STATES V. ELK SHOULDER

federal sex offense, which he committed in 1991. Because
SORNA was not enacted until 2006, he argues that the Ex
Post Facto Clause prohibited Congress from applying the
registration requirement to him.

    Elk Shoulder’s argument is foreclosed by our decision in
United States v. Elkins. In Elkins, a defendant who had been
convicted of a sex offense under Washington law in 1994
failed to register when he moved from Washington to
California in 2010, and was indicted under § 2250. Elkins,
683 F.3d at 1041–42. Elkins filed a motion to dismiss the
indictment arguing, among other things, that the requirement
to register violated the Ex Post Facto Clause in his case
because it was punitive in nature and based on a prior
conviction that occurred before SORNA’s enactment. Id. at
1042–44.      We concluded that SORNA’s registration
requirement was not punitive in nature, and therefore did not
violate Elkins’s constitutional rights. Id. at 1045. Because
Elk Shoulder also argues that SORNA’s registration
requirement cannot be applied to him because it is punitive in
nature, Elkins’s reasoning is equally applicable to Elk
Shoulder.

    Despite this precedent, Elk Shoulder argues that the
Court’s analysis in Smith “no longer hold[s] true in today’s
society,” and that the purpose and effect of SORNA’s
registration requirement are punitive in nature. Elk Shoulder
focuses on the Supreme Court’s holding that the Alaska
registration statute does not resemble shaming punishments
of the colonial period (the first factor of Smith’s five-factor
test), and that there was “no evidence that the [registration
requirement] has led to substantial occupational or housing
disadvantages for former sex offenders that would not have
otherwise occurred through the use of routine background
             UNITED STATES V. ELK SHOULDER                  13

checks by employers and landlords.” Smith v. Doe, 538 U.S.
84, 100 (2003) (the second factor). According to Elk
Shoulder, today SORNA’s registration requirement imposes
significant hardships on offenders, who are “held to public
ridicule by community members,” and face difficulty finding
and maintaining both employment and housing. He notes that
local newspapers frequently maintain interactive maps of the
registered residences of sex offenders, and cites “reports of
incidents of citizens standing on street corners bearing signs
with the names and addresses of offenders blaz[o]ned across
the front.”

    This argument fails. We recently reaffirmed the
nonpunitive nature of SORNA in Elkins, which we are bound
to follow. See Miller v. Gammie, 335 F.3d 889, 899 (9th Cir.
2003) (en banc). Further, Smith v. Doe contemplated that
information from the Alaska sex registration statute would be
available on the internet, but determined that such internet
notification was nonpunitive because its principal effect was
to “inform the public for its own safety, not to humiliate.”
538 U.S. at 99. The Court further noted that there was no
evidence that the Alaska act had “led to substantial
occupational or housing disadvantages for former sex
offenders that would not have otherwise occurred through the
use of routine background checks by employers and
landlords.” Id. at 100. Because “only the clearest proof will
suffice to override legislative intent and transform what has
been denominated a civil remedy into a criminal penalty,” id.
at 92 (internal quotation marks omitted), Elk Shoulder’s
conclusory statements and handful of anecdotal examples
cannot carry the heavy burden of showing substantial changes
in society that would require us to revisit the Supreme Court’s
conclusion.
14           UNITED STATES V. ELK SHOULDER

    We thus reject Elk Shoulder’s argument that application
of the SORNA registration requirements to him on the basis
of his earlier conviction violates the Ex Post Facto Clause.

                              III

    We next turn to Elk Shoulder’s arguments that SORNA’s
registration requirements violate his rights under the Fifth
Amendment, which bars the federal government from
depriving persons of “life, liberty, or property, without due
process of law.” U.S. Const. amend. V.

    Elk Shoulder first asserts that he was deprived of his right
to due process because it was impossible for him to comply
with SORNA. As noted above, in order to convict Elk
Shoulder under § 2250(a), the government had to prove that
Elk Shoulder knowingly failed “to register or update a
registration as required by” SORNA. 18 U.S.C. § 2250(a)(3)
(emphasis added). Elk Shoulder points out that SORNA
required states to adopt the new procedures for sex offender
registries established by the Act, or lose part of their federal
funding. 42 U.S.C. §§ 16924(a), 16925. Elk Shoulder argues
that, because Montana had not yet conformed its sex offense
registry to SORNA’s requirements, it was impossible for him
to register “as required by” SORNA.

    We previously have rejected this argument, both in
United States v. George, 625 F.3d 1124, 1128–29 (9th Cir.
2010), vacated on other grounds, 672 F.3d 1126 (9th Cir.
2012), and in Elkins, 683 F.3d at 1046. As we stated in
Elkins, “the federal government’s prosecution of an alleged
violation of SORNA is not dependent on the individual
state’s implementation of the administrative portion of
SORNA.” Elkins, 683 F.3d at 1046; accord id. at 1046 n.9
             UNITED STATES V. ELK SHOULDER                   15

(the “‘duty to register in a state registry is independent of a
state’s degree of implementation of SORNA.’” (quoting
Felts, 674 F.3d at 603)); see also United States v. Guzman,
591 F.3d 83, 93 (2d Cir. 2010); United States v. Gould,
568 F.3d 459, 464–65 (4th Cir. 2009). Because Elk Shoulder
could have registered with the State of Montana’s registry,
and because this would have allowed him to register “as
required by” SORNA, it was not impossible for Elk Shoulder
to meet the requirements of § 2250(a). Thus, this case
presents no impossibility-based due process problems.

    Second, Elk Shoulder asserts that he did not receive
notice that his failure to register as a sex offender would
violate SORNA, and therefore he did not receive notice
sufficient to comply with the Due Process Clause. This
argument is meritless. In order to convict a defendant under
§ 2250(a), “the government [must] prove that a convicted sex
offender knew of a registration requirement and knowingly
failed ‘to register or update a registration.’” Crowder,
656 F.3d at 876 (quoting 18 U.S.C. § 2250(a)(3)). A
SORNA defendant’s knowledge of his failure to “register or
update a registration” as required by state law is sufficient to
satisfy the “notice” requirement of the Due Process Clause.
Elkins, 683 F.3d at 1049–50; accord United States v. Brown,
586 F.3d 1342, 1351 (11th Cir. 2009) (“[W]e join our sister
circuits in concluding that notice of a duty to register under
state law is sufficient to satisfy the Due Process Clause.”
(internal quotation marks omitted)). The defendant need not
know that the same failure also violates SORNA. Thus,
because Elk Shoulder received notice of his obligation to
register under Montana state law, he received all the notice
the Due Process Clause requires.
16           UNITED STATES V. ELK SHOULDER

                               IV

    Finally, Elk Shoulder argues that his release from federal
custody in May 2008 was “unconditional,” as defined in
Kebodeaux, 133 S. Ct. at 2501 (defining “unconditional” to
mean that, after the defendant’s release, “he was not in ‘any
. . . special relationship with the federal government.’”
(quoting Kebodeaux, 687 F.3d at 234)), and that Congress
therefore lacked the authority under the Property Clause and
Necessary and Proper Clause to apply SORNA to him.

                               A

    Kebodeaux controls our analysis here. In Kebodeaux, a
former member of the United States Air Force, Anthony
Kebodeaux, had been convicted in 1999 by a court-martial for
a federal sex offense. Id. at 2500. After serving a three-
month prison sentence and receiving a bad conduct discharge,
Kebodeaux moved to Texas, where he eventually registered
as a sex offender in 2004. After SORNA became applicable
to him, he moved within Texas without updating his sex
offender registration, and was prosecuted under SORNA for
his failure to register. Id. Kebodeaux appealed his conviction
on the ground that once he had been unconditionally released
from federal custody, Congress did not have the power to
criminalize his failure to register. The Fifth Circuit, sitting en
banc, agreed. It first held that Kebodeaux had been
unconditionally let free from any “special relationship with
the federal government” by the time Congress had enacted
SORNA. Kebodeaux, 687 F.3d at 234. This conclusion was
based in part on the Fifth Circuit’s determination that the
Wetterling Act’s registration requirements did not apply to
the defendant upon his release from prison. Id. at 235 n.4.
Because Kebodeaux was not subject to any federal conditions
             UNITED STATES V. ELK SHOULDER                 17

when SORNA went into effect, the Fifth Circuit concluded,
Congress “lacked the power under Article I’s Necessary and
Proper Clause to regulate through registration [the
defendant’s] intrastate movements.” Kebodeaux, 133 S. Ct.
at 2500.

     The Supreme Court reversed. In explaining the reasons
for its disagreement with the Fifth Circuit, the Supreme Court
stated that “we need not go much further than the Circuit’s
critical assumption that Kebodeaux’s release was
‘unconditional.’” Id. at 2501 (quoting Kebodeaux, 687 F.3d
at 234). Contrary to the Fifth Circuit, the Supreme Court
determined that Kebodeaux was not “an individual who had,
prior to SORNA’s enactment, been ‘unconditionally
released,’” but rather was “an individual already subject to
federal registration requirements [i.e., the Wetterling Act]
that were themselves a valid exercise of federal power.” Id.
at 2504. In reaching this conclusion, the Supreme Court
focused on § 14072(i) of the Wetterling Act, which imposed
federal penalties on convicted sex offenders who failed to
comply with the federal registration provisions. Id. at 2501.
According to the Supreme Court, Kebodeaux had been
continuously subject to two different subsections of
§ 14072(i) from the time of his release from prison. As the
Court explained, § 14072(i)(3) imposed federal criminal
penalties on individuals described in 18 U.S.C. § 4042(c)(4)
who knowingly failed to register in a state where they
resided, and Kebodeaux’s crime of conviction was one
described in § 4042(c)(4). Id. In addition, the Court noted
that § 14072(i)(4) imposed federal penalties on individuals
who were sentenced by a court martial for specified crimes,
and who failed to register as a sex offenders, and held that
this subsection was also applicable to Kebodeaux. Id. at
2501–02. Therefore, the Court concluded that federal
18           UNITED STATES V. ELK SHOULDER

conditions had been continuously imposed on Kebodeaux
under the Wetterling Act from the time of his release from
prison.

    The Court indicated that this conclusion was enough to
resolve the case. Id. at 2502 (“Both the Court of Appeals and
Kebodeaux come close to conceding that if, as of the time of
Kebodeaux’s offense, he was subject to a federal registration
requirement, then the Necessary and Proper Clause
authorized Congress to modify the requirement as in SORNA
and to apply the modified requirement to Kebodeaux. . . .
And we believe they would be right to make this concession.”
(internal quotation marks omitted)). Nevertheless, the Court
went on to consider Congress’s authority to enact the
Wetterling Act and SORNA. As explained in greater detail
below, see infra at pp. 22–23, the Court first held that the
Wetterling Act, as applied to military sex offenders such as
Kebodeaux, was a valid exercise of Congress’s authority
under the Military Regulation Clause and the Necessary and
Proper Clause. Id. at 2502–03. Extending this conclusion,
the Court held that SORNA, which made few changes to the
Wetterling Act, also fell within the scope of Congress’s
authority under these clauses as applied to Kebodeaux. Id. at
2505. Accordingly, the Court concluded that Congress could
constitutionally apply SORNA’s requirements to an
individual like Kebodeaux who had been continuously
subject to valid federal registration requirements after his
release from prison. Id. at 2504.

    The same reasoning applies here. As the Court did in
Kebodeaux, we begin by addressing Elk Shoulder’s argument
that he had not been in “any . . . special relationship with the
federal government” after his release from prison in May
2008. Kebodeaux, 133 S. Ct. at 2501. And as in Kebodeaux,
              UNITED STATES V. ELK SHOULDER                        19

this argument does not withstand scrutiny, because Elk
Shoulder was continuously subject to one or more of the
§ 14072(i) requirements in the Wetterling Act.
Section 14072(i)(2) imposed penalties on “[a] person who is
required to register under a sexual offender registration
program in the person’s State of residence and knowingly
fails to register in any other State in which the person is
employed, carries on a vocation, or is a student.” This section
applied to Elk Shoulder because, upon his release from
prison, he was required to register as a sex offender under
Montana law. Therefore, Elk Shoulder was subject to the
federal requirement to register when he undertook specified
activities in other states. In addition, § 14072(i)(3), which
was relied upon in Kebodeaux, imposed criminal penalties
upon a person described in 18 U.S.C. § 4042(c)(4) who
“knowingly fails to register in any State in which the person
resides, is employed, carries on a vocation, or is a student
following release from prison or sentencing to probation.”
Kebodeaux, 133 S. Ct. at 2501. Because § 4042(c)(4)
described Elk Shoulder’s crime of conviction (as it described
Kebodeaux’s), § 14072(i)(3) potentially applied to Elk
Shoulder.5 Accordingly, under the reasoning in Kebodeaux,
Elk Shoulder was subject to the Wetterling Act upon his
release from prison in May 2008 through August 1, 2008,
when SORNA became applicable to him. His release from
federal custody in May 2008 was therefore not
“unconditional.”




 5
   Although 18 U.S.C. § 4042(c)(4) was repealed July 27, 2006, Pub. L.
No. 109-248, § 141(h), Kebodeaux gave no weight to this fact.
20           UNITED STATES V. ELK SHOULDER

                              B

    In response, Elk Shoulder argues that he was not subject
to the Wetterling Act upon his release because he was
convicted three years before the Act was enacted. Because
the Act does not expressly make its provisions applicable to
pre-enactment offenders, Elk Shoulder contends that the
presumption against the retroactivity of federal statutes
applies. See Vartelas v. Holder, 132 S. Ct. 1479, 1486–87
(2012). Moreover, Elk Shoulder claims that the presumption
against retroactivity has special force here, because
retroactively applying the Wetterling Act to Elk Shoulder
would violate the Ex Post Facto Clause. Cf. Clark v.
Martinez, 543 U.S. 371, 381–82 (2005) (explaining that the
canon of constitutional avoidance “allows courts to avoid the
decision of constitutional questions”). The Supreme Court
did not address these issues in Kebodeaux, because the
defendant in that case was subject to the Wetterling Act “at
the time of his offense and conviction.” Kebodeaux,
133 S. Ct. at 2501.

    We reject Elk Shoulder’s argument. The Wetterling Act
provision applicable to Elk Shoulder, § 14072(i)(2), imposed
federal registration requirements on offenders who had an
ongoing obligation to register under state law, but spent
significant amounts of time in another state. Under its plain
language, § 14072(i)(2) attached a new federal obligation to
Elk Shoulder based on his status as a current state registrant,
not because of his pre-enactment conviction. Elk Shoulder
was required to comply with § 14072(i)(2) because he was
subject to an ongoing Montana registration requirement when
the Wetterling Act became applicable to him, not because he
had previously been convicted of a sex offense. By its terms,
therefore, § 14072(i)(2) does not operate retroactively.
             UNITED STATES V. ELK SHOULDER                   21

    Moreover, the Supreme Court has explained that statutes
imposing requirements on previously convicted individuals
in order to address “dangers that arise postenactment” are not
retroactive. Vartelas, 132 S. Ct. at 1489 n.7. Thus,
“[l]ongstanding prohibitions on the possession of firearms by
felons,” as well as “laws prohibiting persons convicted of a
sex crime against a victim under 16 years of age from
working in jobs involving frequent contact with minors, and
laws prohibiting a person who has been adjudicated as a
mental defective or who has been committed to a mental
institution from possessing guns,” do “not operate
retroactively,” but rather “target a present danger.” Id. at
1489 & n.7 (internal quotation marks omitted). Here, the
applicable Wetterling Act provisions addressed a post-
enactment danger. As later explained in SORNA, they
addressed the danger that the public would not be aware of
potentially dangerous sex offenders living, working, or
attending school in its area. See 42 U.S.C. § 16901 (stating
that SORNA’s purpose is to “protect the public from sex
offenders and offenders against children”). Because only a
patchwork of state registration requirements existed prior to
the Wetterling Act, Congress reasonably addressed the
concern that persons already subject to registration
requirements in their home state would fail to register in other
states where they worked or went to school.                  See
§ 14072(i)(2).

    Because § 14072(i)(2) addressed “dangers that arise
postenactment,” Vartelas, 132 S. Ct. at 1489 n.7, rather than
operating retroactively, the Wetterling Act’s imposition of
criminal penalties on individuals who violate the applicable
registration requirements also does not violate the Ex Post
Facto Clause. See Elkins, 683 F.3d at 1045 (“‘SORNA
provides for a conviction for failing to register; it does not
22             UNITED STATES V. ELK SHOULDER

increase the punishment for past conviction.’” (quoting Felts,
674 F.3d at 606)). We therefore conclude that § 14072(i)(2)
applied to pre-Act offenders such as Elk Shoulder
prospectively, not retrospectively.6

                                    C

    Given our determination that Elk Shoulder was
continuously subject to federal conditions under the
Wetterling Act from the time of his release from prison
through the time of SORNA’s enactment, Kebodeaux
compels the conclusion that SORNA can constitutionally be
applied to Elk Shoulder.

    Once the Court was satisfied that Kebodeaux had never
been “unconditionally released,” Kebodeaux set forth a chain
of logical steps to show why Congress has the authority to
apply SORNA registration requirements to him. First,
Kebodeaux determined that “under the authority granted to it


  6
    To support his argument that the application of these statutes to him
would be retroactive, Elk Shoulder also points to the language in
§ 14071(a)(1)(A) that requires the Attorney General to establish guidelines
for State programs that prospectively require registration of “a person who
is convicted of a criminal offense.” By requiring registration of a person
who “is” convicted, Elk Shoulder argues, Congress did not authorize the
retroactive application of the Wetterling Act’s registration requirement to
a person who “was” convicted in the past.

     This argument fails. The language in § 14071(a)(1)(A) cited by Elk
Shoulder applies to the Attorney General’s promulgation of guidelines for
state registration programs, which as noted above did not preclude states
from applying registration requirements retroactively. The statute does
not impose any obligations on individuals such as Elk Shoulder, and has
no bearing on whether §§ 14071(i)(3) and (4) are applicable to persons
convicted of a sex crime before the Wetterling Act’s enactment.
                 UNITED STATES V. ELK SHOULDER                   23

by the Military Regulation and Necessary and Proper
Clauses, Congress could promulgate the Uniform Code of
Military Justice” and “could specify that the sex offense of
which Kebodeaux was convicted was a military crime under
that Code.” 133 S. Ct. at 2503. Because Congress “could
punish that crime through imprisonment and by placing
conditions upon Kebodeaux’s release,” the Wetterling Act, as
applied to Kebodeaux, was within Congress’s power. Id.
(holding that Congress “could make the civil registration
requirement at issue here a consequence of Kebodeaux’s
offense and conviction”). Kebodeaux then held that, because
“SORNA makes few changes” to the registration
requirements when “applied to an individual already subject
to the Wetterling Act,” Congress could have reasonably
determined that SORNA’s registration requirements were a
“‘necessary and proper’ means for furthering its pre-existing
registration ends.” Id. at 2505. Accordingly, the Court
concluded that “the SORNA changes as applied to
Kebodeaux fall within the scope Congress’ authority.” Id.

   The same chain of logic applies in this case. Here, the
Property Clause, U.S. Const. art. IV, § 3, cl. 2,7 gives
Congress the authority to “make all needful Rules and
Regulations respecting the Territory or other Property


 7
     In full, the Property Clause provides:

          The Congress shall have Power to dispose of and make
          all needful Rules and Regulations respecting the
          Territory or other Property belonging to the United
          States; and nothing in this Constitution shall be so
          construed as to Prejudice any Claims of the United
          States, or of any particular State.

      U.S. Const. art. IV, § 3, cl. 2.
24             UNITED STATES V. ELK SHOULDER

belonging to the United States.” Elk Shoulder does not
dispute that, when read with the Necessary and Proper
Clause, this enumerated power authorized Congress to enact
Elk Shoulder’s crime of conviction, which prohibited a
person from knowingly engaging in a sex act with a person
under twelve years of age “in the special maritime and
territorial jurisdiction of the United States or in a Federal
prison.” 18 U.S.C. § 2241(c); see also United States v.
Comstock, 130 S. Ct. 1949, 1964 (2010) (“Congress has the
implied power to criminalize any conduct that might interfere
with the exercise of an enumerated power . . . .”). In light of
Kebodeaux, it follows that, because Congress could punish
Elk Shoulder’s crime by imprisoning him, it could also apply
the Wetterling Act’s conditions to him after his release. See
Kebodeaux, 133 S. Ct. at 2505. And as in Kebodeaux,
because Elk Shoulder was subject to the Wetterling Act,
Congress could have reasonably found that the SORNA’s
conditions made “few changes” and were a “‘necessary and
proper’ means for furthering its pre-existing registration
ends.” Id. Accordingly, under the reasoning in Kebodeaux,
we conclude that the SORNA requirements as applied to Elk
Shoulder “are within the scope of Congress’ authority.” Id.8


  8
    For the first time in his petition for rehearing, Elk Shoulder contends
that the federal government had jurisdiction to prosecute him under
18 U.S.C. § 2241(c) solely by virtue of the Major Crimes Act, 18 U.S.C.
§ 1153, which “permits the federal government to prosecute Native
Americans in federal courts for a limited number of enumerated offenses
committed in Indian country that might otherwise go unpunished under
tribal criminal justice systems.” United States v. Other Medicine,
596 F.3d 677, 680 (9th Cir. 2010). Based on this assertion, Elk Shoulder
argues that Congress lacked the authority to impose SORNA registration
requirements on him because the Major Crimes Act “must be construed
narrowly, in favor of limited incursion on Native American sovereignty.”
Id.
               UNITED STATES V. ELK SHOULDER                        25

                                  V

   Because SORNA violates neither the Ex Post Facto
Clause nor Elk Shoulder’s constitutional right to due process,
and because Congress acted within its enumerated powers in
enacting SORNA and applying it to individuals like Elk
Shoulder, we affirm the judgment of the district court.

    AFFIRMED.




    We disagree. Although the “canons of construction favoring Native
Americans,” id., may require a narrow construction of § 1153, it is
undisputed that Elk Shoulder was validly made subject to and then
convicted under § 2241(c). Under Kebodeaux, if Congress had the
authority to promulgate and apply § 2241(c) to Elk Shoulder, then
Congress had the implied power to impose SORNA requirements on Elk
Shoulder to further congressional ends. 133 S. Ct. at 2505. Because Elk
Shoulder raises no argument as to why the Major Crimes Act affects
Kebodeaux’s analysis in this regard, we reject his argument.
