                                                                                   FILED
                                                                        United States Court of Appeals
                                                                                Tenth Circuit
                                           PUBLISH
                                                                             December 30, 2011
                          UNITED STATES COURT OF APPEALS
                                                                             Elisabeth A. Shumaker
                                      TENTH CIRCUIT                              Clerk of Court


 UNITED STATES OF AMERICA,

          Plaintiff - Appellee,

    v.                                                         No. 10-1095

 FRANKLIN CAREL, JR.,

             Defendant - Appellant.



               APPEAL FROM THE UNITED STATES DISTRICT COURT
                       FOR THE DISTRICT OF COLORADO
                         (D.C. NO. 1:09-CR-00133-WYD-1)


Jill M. Wichlens, Assistant Federal Public Defender (Raymond P. Moore, Federal Public
Defender, with her on the briefs), Office of the Federal Public Defender for the District of
Colorado, Denver, Colorado, appearing for Appellant.

Michael C. Johnson, Assistant United States Attorney (John F. Walsh, United States
Attorney, with him on the brief), Office of the United States Attorney for the District of
Colorado, Denver, Colorado, appearing for Appellee.


Before GORSUCH, ANDERSON, and MATHESON, Circuit Judges.


MATHESON, Circuit Judge.


         In 2010, Defendant-Appellant Franklin Carel, Jr., a federally adjudicated sex

offender, was convicted of knowingly failing to update his sex offender registration as


                                                1
required by the Sex Offender Registration and Notification Act (“SORNA”). On appeal,

he contends that SORNA’s sex offender registration provision, 42 U.S.C. § 16913, is

unconstitutional. Exercising jurisdiction pursuant to 28 U.S.C. § 1291, we hold that as

applied to Mr. Carel—a federal sex offender on supervised release—§ 16913 is a

constitutional exercise of Congress’s authority under the Necessary and Proper Clause.

                                I.    BACKGROUND

       A. Substantive Background

           1. SORNA: History and Framework

       “In the years prior to SORNA’s enactment, the Nation had been shocked by cases

in which children had been raped and murdered by persons who, unbeknownst to their

neighbors or the police, were convicted sex offenders.” Carr v. United States, 130 S. Ct.

2229, 2249 (2010) (Alito, J., dissenting). In response to these events, “Congress and state

legislatures passed [several] laws requiring the registration of sex offenders.” Id. One

such law was the federal Jacob Wetterling Crimes Against Children and Sexually Violent

Offender Registration Act (the “Wetterling Act”), Pub. L. 103-322, Tit. XVII,

§ 170101(c), 108 Stat. 2041.1

       Despite federal and state efforts to monitor convicted sex offenders, approximately

100,000 sex offenders—nearly one-fifth of the United States’ total sex offender

       1
       “Under the Wetterling Act, states were given three years to establish a sex
offender registration program in compliance with the Act or forfeit 10 percent of federal
funding for a state and local law enforcement assistance program.” United States v.
Begay, 622 F.3d 1187, 1189 (9th Cir. 2010). “The Wetterling Act required convicted sex
offenders to register their addresses with states.” Id. The Wetterling Act was replaced by
the Adam Walsh Child Protection and Safety Act of 2006, Pub. L. No. 109-248, § 129(a),
120 Stat. 587, which contains more specific sex offender registration requirements.
                                              2
population—remained unregistered in 2005. See H. R. Rep. No. 109-218, pt. 1, p. 26

(2005). In July 2006, Congress enacted the Adam Walsh Child Protection and Safety Act

(the “Walsh Act”), Pub. L. No. 109-248, §§ 1-155, 120 Stat. 587, 590-611 (2006). Title I

of the Walsh Act established SORNA. See id.

       “SORNA was enacted to succeed and enhance the registration requirements of the

Wetterling Act,” United States v. Begay, 622 F.3d 1187, 1190 (9th Cir. 2010), and to

eliminate “a dangerous gap in the then-existing sex-offender-registration laws.” Carr,

130 S. Ct. at 2249 (Alito, J., dissenting); see also United States v. Yelloweagle, 643 F.3d

1275, 1277 (10th Cir. 2011) (noting that SORNA was enacted based on Congress’s

“conclusion that existing sex offender registration and reporting requirements were too

readily circumvented”).

       The declared purpose of SORNA is “to protect the public from sex offenders and

offenders against children . . . [by] establish[ing] a comprehensive national system for the

registration of those offenders.” 42 U.S.C. § 16901. To accomplish this objective,

SORNA established a national database, see 42 U.S.C. § 16919(a), “[i]ntended as a

means of preventing sex offenders from evading their registration requirements by

crossing state lines.” United States v. Lawrance, 548 F.3d 1329, 1334 (10th Cir. 2008);

see also Carr, 130 S. Ct. at 2240 (noting that SORNA was “enacted to address the

deficiencies in prior law that had enabled sex offenders to slip through the cracks”).

       SORNA includes civil and criminal components. Its civil component—42 U.S.C.

§ 16913—states: “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

                                               3
offender is a student.” SORNA defines the term “sex offender” as “an individual who

was convicted of a sex offense.” Id. at 16911(1). Section 16913 “requires all sex

offenders to register [and to keep their registrations current], regardless of whether their

convictions are based on federal or state law.” Yelloweagle, 643 F.3d at 1276; see also

Begay, 622 F.3d at 1187 (noting that § 16913 imposes “two separate obligations—an

obligation to register and an obligation to keep the registration current”). To ensure such

compliance, 18 U.S.C. § 3583(d) requires federal district courts to “order, as an explicit

condition of supervised release for a person required to register under [SORNA], that the

person comply with the requirements of that Act.” Thus, for all persons convicted of a

federal sex offense after SORNA’s enactment, the registration requirements contained in

§ 16913 are a mandatory component of their supervised release. See id.

       SORNA’s criminal provision—18 U.S.C. § 2250(a)—imposes criminal penalties

for failure to comply with § 16913’s registration requirements. Section 16913 “applies to

all sex offenders regardless of whether their convictions arise under federal or state law.”

Yelloweagle, 643 F.3d at 1278. By contrast, § 2250(a) “imposes criminal liability on two

categories of persons who fail to adhere to SORNA’s registration requirements: (1) any

person who is a sex offender by reason of a conviction under federal law, and (2) any

other [sex offender] who travels in interstate or foreign commerce.” Carr, 130 S. Ct. at

2238 (quotations and citations omitted). Persons convicted of state sex crimes “who

never leave the state in which they were convicted” are not subject to criminal penalties

under § 2250(a). Yelloweagle, 643 F.3d at 1278.



                                                4
           2. SORNA: Tenth Circuit Litigation

       In the years since its passage, the Tenth Circuit has rejected numerous

constitutional challenges to SORNA. The court has held that § 16913—SORNA’s

registration provision—does not violate the Due Process Clause, the nondelegation

doctrine, or the Ex Post Facto Clause. See, e.g., Lawrance, 548 F.3d at 1333-34; United

States v. Hinckley, 550 F.3d 926, 935-40 (10th Cir. 2008). We also have held that

Congress acted within its authority under the Commerce Clause in enacting §

2250(a)(2)(B)—SORNA’s criminal provision applicable to sex offenders who fail to

register and travel in interstate or foreign commerce. See Lawrance, 548 F.3d at 1337;

Hinckley, 550 F.3d at 940.

       Most recently, we held that Congress acted within its authority under the

Necessary and Proper Clause when it enacted § 2250(a)(2)(A)—SORNA’s criminal

provision that applies to federal sex offenders, including those who do not travel

interstate. See Yelloweagle, 643 F.3d at 1289.2 We reached this conclusion based on the

assumption that § 16913—SORNA’s registration provision—was constitutional. See id.

Specifically, we stated: “[O]perat[ing] on the assumption that § 16913 is a valid exercise

of Congress’s power under the Commerce Clause . . . we conclude that Congress has the

authority under the Necessary and Proper Clause to enact § 2250(a)(2)(A) in order to

criminally enforce its validly enacted registration provision, § 16913.” Id. We assumed


       2
       On appeal, Mr. Carel asserts a facial challenge to the constitutionality of
§ 2250(a)(2)(A), but this challenge is foreclosed by our decision in Yelloweagle.
                                               5
§ 16913 was valid because the defendant-appellant “waived his challenge to § 16913.”

Id.

       Despite all the constitutional challenges to SORNA that have been asserted in the

Tenth Circuit, we have not expressly addressed whether Congress acted within the scope

of its authority when it required federal sex offenders to comply with § 16913’s

registration requirements. 3


       3
         Two other circuits—the Fifth and the Ninth—have directly addressed the
constitutionality of applying § 16913 to federal sex offenders. See United States v.
Kebodeaux, 647 F.3d 137 (5th Cir. 2011) (en banc opinion pending); United States v.
George, 625 F.3d 1124 (9th Cir. 2010). Although they offered different reasons for
doing so, both circuits upheld § 16913 as a constitutional exercise of Congress’s
legislative authority. See Kebodeaux, 647 F.3d at 146 (“Congress had the authority under
Article I of the Constitution to devise a narrow, non-punitive collateral regulatory
consequence to this particular high-risk category of federal criminal convictions. . . .
Accordingly, we conclude that [SORNA’s] application to intra-state violations . . . by sex
offenders convicted under federal law is constitutional.”); George, 625 F.3d at 1130
(“SORNA’s registration requirements are valid based on the federal government’s direct
supervisory interest over federal sex offenders.” (quotations omitted)).
        Additionally, although they have not addressed application of § 16913 to federal
sex offenders who do not cross state lines, at least six other circuits have concluded that
§ 16913 is constitutional. See United States v. Pendleton, 636 F.3d 78, 88 (3d Cir. 2011)
(“Section 16913 is a law made in pursuance of the constitution, because it is necessary
and proper for carrying into Execution Congress’s power under the Commerce Clause.”
(quotations and citations omitted)); United States v. Guzman, 591 F.3d 83, 91 (2d Cir.
2010) (“To the extent that § 16913 regulates solely intrastate activity, its means are
reasonably adapted to the attainment of a legitimate end under the commerce power, and
therefore proper.” (quotations and citations omitted)); United States v. DiTomasso, 621
F.3d 17, 25 n.8 (1st Cir. 2010) (“The defendant suggests that the registration requirement
contained in § 16913 itself exceeds Congress’s power under the Commerce Clause. This
suggestion is incorrect. The Necessary and Proper Clause . . . provides Congress with
ample authority to regulate local activity as part of a general scheme regulating interstate
commerce.”); United States v. Vasquez, 611 F.3d 325, 331 (7th Cir. 2010) (“[Section]
16913 is a logical way to help ensure that the government will more effectively be able to
track sex offenders when they do cross state lines. To the extent that § 16913 regulates
solely intrastate activity, the regulatory means chosen are ‘reasonably adapted’ to the
attainment of a legitimate end under the commerce power.”); United States v. Howell,
                                               6
       B. Factual Background and Procedural History

       In 2006, Mr. Carel, then 22 years old, impregnated his 14-year-old girlfriend.

Both Mr. Carel and his girlfriend lived on Colorado’s Southern Ute Indian Reservation.

The pregnancy eventually came to the attention of the Southern Ute Social Services

Department.

       In January 2008, Mr. Carel was charged with one count of sexual abuse of a minor

in Indian country in violation of 18 U.S.C. § 2243(a)4 and 18 U.S.C. § 1153.5 In August

2008, he pled guilty to the charge. A federal district court sentenced Mr. Carel to time

served and to three years of supervised release. One of the conditions of his supervised

release is that he “comply with the requirements of [SORNA] as directed by the

probation officer, the Bureau of Prisons, or any state sex offender registration agency [in

any state in which] he . . . resides, works, or is a student.” Aplt. App. Vol. I, at 44.




552 F.3d 709, 715 (8th Cir. 2009) (“[A]n analysis of § 16913 under the broad authority
granted to Congress through both the commerce clause and the enabling necessary and
proper clause reveals the statute is constitutionally authorized.”); United States v. Ambert,
561 F.3d 1202, 1212 (11th Cir. 2009) (“Section 16913 is reasonably adapted to the
attainment of a legitimate end under the commerce clause. The requirement that sex
offenders register under § 16913 is necessary to track those offenders who move from
jurisdiction to jurisdiction.”).
       4
       18 U.S.C. § 2243(a) criminalizes “knowingly engag[ing] in a sexual act with
another person who—(1) has attained the age of 12 years but has not attained the age of
16 years; and (2) is at least four years younger than the person so engaging . . . .”
       5
        18 U.S.C. § 1153 states: “Any Indian who commits . . . felony child abuse or
neglect . . . within the Indian country, shall be subject to the same law and penalties as all
other persons committing any of the above offenses, within the exclusive jurisdiction of
the United States.”
                                                7
       On December 19, 2008, Mr. Carel met with a federal probation officer and signed

a document titled “Conditions of Probation and Supervised Release.” By signing the

document, Mr. Carel agreed to “register as a sex offender in any state where [he] resides,

is employed, carries on a vocation, or is a student.” Id. at 52.

       Mr. Carel moved to Bayfield, Colorado to live with a family friend some time in

December 2008. On December 24, 2008, he registered as a sex offender in Colorado.

His sex offender registration form indicated that he was required to re-register quarterly

and that his next registration date was March 24, 2009. Mr. Carel did not re-register on

that date.

       On March 24, 2009, a federal grand jury indicted Mr. Carel for failure to update

his sex offender registration in Colorado. At the time of his indictment, Mr. Carel

remained on supervised release for his original conviction for sexual abuse of a minor in

Indian country. The March 24, 2009 indictment stated that Mr. Carel, “a person who was

required to register under [SORNA], and a sex offender by reason of a conviction under

[f]ederal law, did knowingly fail to update his registration as required by law . . . in

violation of 18 U.S.C. § 2250(a).” Id. at 5. The district court issued an arrest warrant

based on the indictment. On May 1, 2009, authorities arrested Mr. Carel pursuant to the

warrant in the state of Arizona.6



       6
       Although Mr. Carel was arrested in Arizona and could possibly have been
prosecuted under § 2250(a)(2)(B)—SORNA’s criminal provision applicable to sex
offenders who fail to register and travel in interstate or foreign commerce—the
Government chose to prosecute him under § 2250(a)(2)(A).

                                                8
       On June 23, 2009, Mr. Carel filed a motion to dismiss his indictment, arguing that

SORNA’s registration provision is unconstitutional. The district court rejected his

argument and denied his motion.

       On March 17, 2010, Mr. Carel entered a conditional guilty plea, preserving his

right to appeal the district court’s denial of his motion to dismiss. The district court

sentenced him to 15 months of imprisonment to be followed by three years of supervised

release.

       Mr. Carel filed a timely notice of appeal challenging the district court’s rejection

of his motion to dismiss.7

                                     II. ANALYSIS

       On appeal, Mr. Carel contends that “[t]he registration requirement of . . . § 16913

is unconstitutional as applied to federally adjudicated sex offenders.” Aplt. Br. at 24.

Specifically, he argues that Congress exceeded the scope of its authority under the

Commerce Clause by requiring federal sex offenders who do not cross state lines to

comply with § 16913. He further argues that application of § 16913 to federal sex

offenders is not a proper exercise of Congress’s authority under the Necessary and Proper

Clause.


       7
        In his opening brief, Mr. Carel addressed two issues. First, he contended he “is
not guilty . . . of violating 18 U.S.C. § 2250 because he was not in fact required by
SORNA to update his registration after only three months.” Aplt. Br. at 11. Second, he
argued “[t]he Constitution does not grant Congress the authority to enact the civil
registration requirement of SORNA (42 U.S.C. § 16913-16916).” Id. at 23. However, in
his reply brief, Mr. Carel abandoned the first issue raised in his opening brief. We
therefore address only his second issue.

                                                9
       In response, the Government argues that § 16913 is a valid exercise of Congress’s

authority to regulate “persons . . . in interstate commerce.” Aple. Br. at 39.

Alternatively, it argues that, even if the Commerce Clause does not authorize Congress to

require federal sex offenders to comply with SORNA’s registration requirements, the

Necessary and Proper Clause provides it with such authority.

       In reviewing the constitutionality of § 16913, our review is de novo. See United

States v. Plotts, 347 F.3d 873, 877 (10th Cir. 2003). We must, however, presume that the

statute is constitutional. See id. (“We review challenges to the constitutionality of a

statute de novo . . . . Statutes are presumed constitutional.” (quotations and citations

omitted)); see also Gillmor v. Thomas, 490 F.3d 791, 798 (10th Cir. 2007) (“As a general

matter, we give all statutes a presumption of constitutionality.”). The Supreme Court has

instructed that “[d]ue respect for the decisions of a coordinate branch of Government

demands that we invalidate a congressional enactment only upon a plain showing that

Congress has exceeded its constitutional bounds.” United States v. Morrison, 529 U.S.

598, 607 (2000).

       With this presumption of constitutionality in mind, we turn to whether Congress

exceeded the scope of its authority under Article I, § 8 of the Constitution by requiring

Mr. Carel to register as a sex offender. Based on Congress’s authority to enact Mr.

Carel’s original statute of conviction (sexual abuse of a minor in Indian country) and its

power to create civil penalties and regulations for persons convicted of violating that

statute under the Necessary and Proper Clause, we hold that Congress did not exceed the

scope of its authority by requiring Mr. Carel—a federal sex offender on supervised

                                               10
release—to register as a sex offender. We therefore need not and do not review

§ 16913’s constitutionality under the Commerce Clause.

       We begin our analysis by addressing the scope of Mr. Carel’s constitutional

challenge to § 16913. After determining that Mr. Carel’s challenge to § 16913 is an as-

applied challenge, we address the merits of his claim.

    A. The Scope of Mr. Carel’s Claim

       “Our first task in resolving [Mr. Carel’s challenge] is to determine the contours of

[his] claim.” Milavetz, Gallop & Milavetz, P.A. v. United States, 130 S. Ct. 1324, 1339

(2010). An appellant may challenge the constitutionality of a statute by asserting a facial

challenge, an as-applied challenge, or both. See, e.g., Kan. Judicial Review v. Stout, 519

F.3d 1107, 1118 (10th Cir. 2008). “A facial challenge is a head-on attack [of a]

legislative judgment, an assertion that the challenged statute violates the Constitution in

all, or virtually all, of its applications.” United States v. Pruitt, 502 F.3d 1154, 1171

(10th Cir. 2007).

       In contrast, “[a]n as-applied challenge concedes that the statute may be

constitutional in many of its applications, but contends that it is not so under the

particular circumstances of the case.” Id. (emphasis added); see also New Mexico Youth

Organized v. Herrera, 611 F.3d 669, 677 n.5 (10th Cir. 2010) (“[An] ‘as-applied’

challenge to a law acknowledges that the law may have some potential constitutionally

permissible applications, but argues that the law is not constitutional as applied to

[particular parties].”).



                                                11
       “The nature of a challenge depends on how the plaintiffs elect to proceed—

whether they seek to vindicate their own rights based on their own circumstances (as-

applied) or whether they seek to invalidate a[] [statute] based on how it affects them as

well as other conceivable parties (facial).” Scherer v. United States Forest Serv., 653

F.3d 1241, 1245 (10th Cir. 2011) (second and third emphases added).

       Mr. Carel’s claim that § 16913 is unconstitutional has characteristics of both a

facial and as-applied challenge. It has characteristics of a facial challenge to the extent

that “it is not limited to the [facts of his] particular case,” Doe v. Reed, 130 S. Ct. 2811,

2817 (2010), and seeks to challenge the application of § 16913 to all persons convicted of

a federal sex offense. See id. It has characteristics of an as-applied challenge “in the

sense that it does not seek to strike down [§ 16913] in all its applications.” Id.

       Although the nature of Mr. Carel’s challenge is not entirely clear from his briefing

or the decision below, at oral argument his counsel stated that his challenge to § 16913 is

an as-applied challenge: “Our challenge is an as-applied challenge to the registration

provisions. That is because this court in Lawrance and other circuits have held that the

registration requirement is constitutional . . . as applied to those that travel in interstate

commerce. So, th[is] is an as-applied challenge that we’re making to [§ 16913].” Oral

Argument at 00:50-02:00. Counsel for the Government agreed. See id. at 15:38-16:01.

We therefore address the merits of Mr. Carel’s claim consistent with that

characterization. See, e.g., Milavetz, 130 S. Ct. at 1339 (“Although the nature of its

challenge is not entirely clear from the briefing or decisions below, counsel . . . insisted



                                                 12
at oral argument that this is . . . an as-applied challenge . . . . We will approach the

question consistent with [counsel’s] characterization.” (quotations and citations omitted)).

        Because we construe Mr. Carel’s challenge to § 16913 as an as-applied challenge,

we address only whether applying § 16913 to the particular circumstances of his case

violates the Constitution and we express no opinion concerning whether § 16913 might

violate the Constitution as it applies to other federal sex offenders. Cf. Pruitt, 502 F.3d at

1171; see also Colorado Right to Life Comm., Inc. v. Coffman, 498 F.3d 1137, 1146 (10th

Cir. 2007) (“[A]n as-applied challenge tests the application of [a statute] to the facts of a

plaintiff’s concrete case.”). Accordingly, we determine only whether Congress exceeded

the scope of its authority by requiring Mr. Carel—a federal sex offender on supervised

release—to register as a sex offender.

      B. The Merits of Mr. Carel’s As-Applied Challenge to § 16913

         1. The Necessary and Proper Clause

        “The federal government is acknowledged by all to be one of enumerated

powers.” United States v. Comstock, 130 S. Ct. 1949, 1956 (2010) (quotations omitted).

Thus, “[e]very law enacted by Congress must be based on one or more of those powers.”

Id.

        Here, the issue is whether application of § 16913 to Mr. Carel exceeds the scope

of Congress’s enumerated powers. We hold that it does not. Specifically, based on

Congress’s authority to enact Mr. Carel’s original statute of conviction, we hold that

Congress had corresponding Necessary and Proper Clause authority to require Mr.

Carel—a federal sex offender on supervised release for violating that statute—to comply

                                                13
with § 16913’s registration provisions. See Comstock, 130 S. Ct. at 1964 (noting that the

Necessary and Proper Clause provides Congress with authority to regulate the behavior

of federal offenders “even after their release”); United States v. Plotts, 347 F.3d 873, 879

(10th Cir. 2003) (“[P]ursuant to the Necessary and Proper Clause Congress may fashion

penalties for the violation of valid federal laws.”).

        The Necessary and Proper Clause provides that “[t]he Congress shall have Power

. . . To make all Laws which shall be necessary and proper for carrying into Execution the

foregoing Powers, and all other Powers vested by this Constitution in the Government of

the United States, or in any Department or Officer thereof.” U.S. Const. art. I, § 8, cl. 18.

In the landmark case of McCulloch v. Maryland, 17 U.S. (4 Wheat.) 316 (1819), the

Supreme Court—with Chief Justice Marshall writing—explained that the Necessary and

Proper Clause accords Congress “the right to legislate in that vast mass of incidental

powers which must be involved in the constitution, if that instrument be not a splendid

bauble.” Id. at 421. The Court emphasized that the word “necessary” does not mean

“absolutely necessary.” Id. at 413-15. In a passage that has come to define the scope of

the Necessary and Proper Clause, Chief Justice Marshall stated: “Let the end be

legitimate, let it be within the scope of the constitution, and all means which are

appropriate, which are plainly adapted to that end, which are not prohibited, but consist

with the letter and spirit of the constitution, are constitutional.” Id.; see also Comstock,

130 S. Ct. at 1956 (noting that Chief Justice Marshall’s ends/means test “has come to

define the scope of the Necessary and Proper Clause”).



                                                14
       The Supreme Court has consistently recognized the breadth of the Necessary and

Proper Clause. See, e.g., Free Enter. Fund v. Pub. Co. Accounting Oversight Bd., 130 S.

Ct. 3138, 3165 (2010) (“Congress has broad power to enact statutes ‘necessary and

proper’ to the exercise of its specifically enumerated constitutional authority.”);

Katzenbach v. Morgan, 384 U.S. 641, 650 (1966) (“By including § 5 the draftsmen

sought to grant to Congress, by a specific provision applicable to the Fourteenth

Amendment, the same broad powers expressed in the Necessary and Proper Clause.”

(emphasis added)).

       In Comstock the Court stated that “the Necessary and Proper Clause grants

Congress broad authority to enact federal legislation.” 130 S. Ct. at 1956. The Court

stated: “[E]very law enacted by Congress must be based on one of or more [of its

enumerated] powers. But, at the same time, a government entrusted with such powers

must be entrusted with ample means for their execution.” Id. (quotations and citations

omitted). The Court further stated that “the Necessary and Proper Clause makes clear

that the Constitution’s grants of specific federal legislative authority are accompanied by

broad power to enact laws that are ‘convenient or useful’ or ‘conducive’ to the authority’s

beneficial exercise.” Id. Of course, a law enacted pursuant to Congress’s authority under

the Necessary and Proper Clause cannot violate other constitutional provisions. See

Plotts, 347 F.3d at 878.

       “In determining whether the Necessary and Proper Clause grants Congress the

legislative authority to enact [or apply] a particular federal statute, we look to see whether

the statute constitutes a means that is rationally related to the implementation of a

                                               15
constitutionally enumerated power.” Comstock, 130 S. Ct. at 1956; see also Gonzales v.

Raich, 545 U.S. 1, 22 (2005) (holding that because “Congress had a rational basis” for

concluding that a statute implemented Commerce Clause power, the statute fell within

the scope of congressional “authority to make all laws which shall be necessary and

proper” (quotations omitted)); Sabri v. United States, 541 U.S. 600, 605 (2004) (using the

“means-ends rationality” to determine if Congress had authority to enact a statute under

the Necessary and Proper Clause); Plotts, 347 F.3d at 878 (“At bottom, . . . the Necessary

and Proper Clause enables Congress to enact laws, subject to other constitutional

restraints, that bear a rational connection to any of its enumerated powers.” (quotations

omitted)).

       The Court has explained that a statute can be rationally related to the

implementation of a constitutionally enumerated power even if there is “more than a

single step between an enumerated power and [the Statute].” Comstock, 130 U.S. at

1964. Thus, a statute need only be “ultimately derived from an enumerated power,” id.

(quotations omitted), and “rationally related to the implementation of [the]

constitutionally enumerated power” to be a proper exercise of Congress’s authority under

the Necessary and Proper Clause. Id. at 1956.

       For instance, apart from a few limited exceptions, “Congress’s power to

criminalize conduct . . . is [not] explicitly mentioned in the Constitution.” Id. at 1958.

But the Supreme Court has consistently held that the Necessary and Proper Clause

provides Congress “implied power to criminalize any conduct that might interfere with

the exercise of an enumerated power.” Id. at 1964; see also, e.g., id. at 1957 (“[T]he

                                               16
Constitution, which nowhere speaks explicitly about the creation of federal crimes

beyond those related to counterfeiting, treason, or Piracies and Felonies committed on the

high Seas or against the law of Nations, nonetheless grants Congress broad authority to

create such crimes.” (quotations and citations omitted)); Sabri, 541 U.S. at 605

(upholding a criminal statute enacted in furtherance of the Spending Clause); Jinks v.

Richland Cnty., 538 U.S. 456, 462 n.2 (2003) (describing perjury and witness tampering

as federal crimes enacted in furtherance of the power to constitute federal tribunals);

Lottery Case, 188 U.S. 321 (1902) (upholding a criminal statute enacted in furtherance of

the Commerce Clause); Ex parte Yarbrough, 110 U.S. 651 (1884) (upholding Congress’s

authority to enact a federal statute criminalizing civil-rights violations because it was

necessary and proper to protect suffrage rights conferred under the Fifteenth

Amendment).

       Similarly, neither Congress’s power to punish individuals who violate its laws,

“nor its power to enact laws governing prisons and prisoners, is explicitly mentioned in

the Constitution.” Comstock, 130 S. Ct. at 1958. But the Court has stated that “Congress

nonetheless possesses broad authority to do each of those things in the course of carrying

into Execution the enumerated powers vested by the Constitution in the Government of

the United States—authority granted by the Necessary and Proper Clause.” Id. at 1958

(quotations and citations omitted); see also McCulloch, 17 U.S. at 416 (“All admit that

the government may, legitimately, punish any violation of its laws; and yet, this is not

among the enumerated powers of Congress.”).



                                               17
       For example, in Greenwood v. United States, 350 U.S. 366 (1956), the Court

upheld the civil commitment of a mentally incompetent federal defendant who was

accused of robbing a United States Post Office as an appropriate exercise of

congressional power under the Necessary and Proper Clause. See id. at 369, 375.

Recently, the Court explained that the enumerated Article I power underlying its decision

in Greenwood was “the power to ‘Establish Post Offices and Post Roads.’” Comstock,

130 S. Ct. at 1963 (quoting U.S. Const. art. I, § 8, cl. 7). The Court noted: “[A]s Chief

Justice Marshall recognized in McCulloch, ‘the power to establish post offices and post

roads . . . is executed by the single act of making the establishment.’” Id. (quoting

McCulloch, 17 U.S. at 417). The Court then explained that from the enumerated power

to establish post offices and post roads “has been inferred the right to punish those who

steal letters from the post office or rob the mail.” Id. (quotations omitted). Additionally,

it explained that “from the implied power to punish [has been] further inferred both the

power to imprison” and the power to impose civil sanctions on those who violate validly

enacted federal laws. Id. (quotations omitted).

       The Court recently applied its Necessary and Proper Clause analysis to a federal

criminal statute in United States v. Comstock. See 130 S. Ct. 1949. In Comstock, the

Court was called upon to determine whether the Necessary and Proper Clause authorized

Congress to enact a federal statute that permits the civil commitment of a mentally ill,

sexually dangerous federal prisoner beyond the date the prisoner would otherwise be

released from federal custody. Id. at 1954. The Court concluded that the federal

statute—18 U.S.C. § 4248—was “reasonably adapted to Congress’s power to act as a

                                               18
responsible federal custodian.”8 Id. at 1961. It explained that the power “to act as a . . .

federal custodian . . . rests . . . upon federal criminal statutes that legitimately seek to

implement constitutionally enumerated authority.” Id. The Court then stated:

              Congress could have reasonably concluded that federal
              inmates who suffer from a mental illness that causes them to
              “have serious difficulty in refraining from sexually violent
              conduct,” § 4247(a)(6), would pose an especially high danger
              to the public if released. Cf. H. R. Rep. No. 109-218, at 22-
              23. And Congress could also have reasonably concluded (as
              detailed in the Judicial Conference’s report) that a reasonable
              number of such individuals would likely not be detained by
              the States if released from federal custody, in part because the
              Federal Government itself severed their claim to “legal
              residence in any State” by incarcerating them in remote
              federal prisons. H. R. Rep. No. 1319, at 2; Committee
              Report 7-11, App. 69-75; cf. Post, at ___, 176 L. Ed. 2d, at
              902 (Kennedy, J., concurring in judgment). Here, Congress’
              desire to address the specific challenges identified in the
              Reports cited above, taken together with its responsibilities as
              a federal custodian, supports the conclusion that § 4248
              satisfies “review for means-end rationality,” i.e., that it
              satisfies the Constitution’s insistence that a federal statute
              represent a rational means for implementing a constitutional


       8
         In Comstock, the Court relied on five considerations in reaching its conclusion
that § 4248 was constitutional: “(1) the breadth of the Necessary and Proper Clause, (2)
the long history of federal involvement in this arena, (3) the sound reasons for the
statute’s enactment in light of the Government’s custodial interest in safeguarding the
public from dangers posed by those in federal custody, (4) the statute’s accommodation
of state interests, and (5) the statute’s narrow scope. See 130 S. Ct. at 1965. Although
the Court referenced these considerations, it did not suggest that they should be balanced
or considered in every Necessary and Proper Clause analysis. See Kebodeaux, 647 F.3d
at 142-43 (en banc opinion pending); see also Yelloweagle, 643 F.3d at 1284-85
(referencing Comstock but not addressing its five considerations). Rather, the five
considerations appear to be an articulation of the reasons that supported the Court’s
conclusion that the statute at issue was constitutional. See Kebodeaux, 647 F.3d at 142-
43.


                                                 19
              grant of legislative authority. Sabri, 541 U.S., at 605 (citing
              McCulloch, 17 U.S. 316).

Id. at 1961-62 (second emphasis added and some citations omitted).

       We applied a similar Necessary and Proper Clause analysis in United States v.

Plotts. See 347 F.3d at 877-80. In Plotts, the defendant pled guilty to possession of child

pornography. See id. at 875. As a condition of his supervised release, the defendant was

required to “cooperate in the collection of his DNA” as required by the DNA Act. Id.

On appeal, the defendant challenged the constitutionality of the DNA Act, arguing that

Congress had exceeded the scope of its “authority to legislate” by enacting it. Id. at 877.

       We rejected the defendant’s claim, explaining that “the Necessary and Proper

Clause enables Congress to enact laws, subject to other constitutional restraints, that bear

a rational connection to any of its enumerated powers.” Id. at 878 (quotations omitted).

We then explained that under the Necessary and Proper Clause, “Congress has the power

to impose nonpunitive sanctions for the violations of criminal statutes.” Id. at 879 n.5;

see also Yelloweagle, 643 F.3d at 1285 (“Congress, in order to help ensure the

enforcement of federal criminal laws enacted in furtherance of its enumerated powers,

can erect civil regulatory regimes rationally related to effectuating a constitutional grant

of legislative authority, which the enumerated powers provide.” (quotations and citations

omitted)). After determining that the “Commerce Clause empower[ed] Congress to

criminalize the receipt of child pornography over the internet—the crime to which [the

defendant] pled guilty,” Plotts, 347 F.3d at 879, we concluded that Congress was

authorized under the Necessary and Proper Clause to enact the DNA Act as an


                                               20
appropriate civil sanction for the violation of the validly enacted federal law. See id. at

880.

        2. Application to Mr. Carel’s Claim

       The cases addressed in the foregoing discussion demonstrate that, pursuant to the

Necessary and Proper Clause, “Congress has the implied power to criminalize any

conduct that might interfere with the exercise of an enumerated power, and also the

additional power to imprison people who violate those (inferentially authorized) laws,

and the additional power to provide for the safe and reasonable management of those

prisons, and the additional power to regulate those prisoners’ behavior even after their

release.” Comstock, 130 U.S. at 1964 (emphasis added). They further demonstrate that

Congress also has the power to impose nonpunitive civil sanctions on individuals

convicted of violating a validly enacted federal criminal statute. See id. at 1965; Plotts,

347 F.3d at 879 n.5. “[E]ach of th[e]se powers . . . is ultimately derived from . . . the

enumerated power that justifies a criminal defendant’s arrest or conviction.” Comstock,

130 U.S. at 1964 (quotations omitted).

       Mr. Carel’s status as a sex offender is based on his prior conviction for sexual

abuse of a minor in Indian country. Like the child pornography statute at issue in Plotts,

it is undisputed that Congress has authority to criminalize sexual abuse of a minor in

Indian country. See, e.g., United States v. Kagama, 118 U.S. 375, 383-85 (1886)

(holding that Congress has authority to criminalize conduct that occurs on Indian

reservations); see also United States v. Jicarilla Apache Nation, 131 S. Ct. 2313, 2327

(2011) (recognizing Kagama as sound authority). Indeed, the Supreme Court has

                                               21
expressly stated that “Congress has undoubted constitutional power to prescribe a

criminal code applicable in Indian country.” United States v. Antelope, 430 U.S. 641,

648 (1977). Accordingly, to determine whether Congress exceeded the scope of its

authority by requiring Mr. Carel to register as a sex offender, we need only decide

whether § 16913 “is rationally related to the effectuation of that criminal statute and,

thus, consonant with the Constitution’s insistence that a federal statute represent a

rational means for implementing a constitutional grant of legislative authority.”

Yelloweagle, 643 F.3d at 1287 (quotations and citations omitted).

       We conclude that application of § 16913 to Mr. Carel—a federal sex offender on

supervised release—satisfies this rational-relation test. As applied to Mr. Carel, § 16913

is “reasonably adapted,” United States v. Darby, 312 U.S. 100, 121 (1941), to the

effectuation of the statute under which Mr. Carel was convicted and to Congress’s

authority to impose nonpunitive civil sanctions on those who violate validly enacted

federal criminal statutes. See Comstock, 130 U.S. at 1964-65; Plotts, 347 F.3d at 879 n.5.

       SORNA’s declared purpose is to “to protect the public from sex offenders and

offenders against children . . . [by] establish[ing] a comprehensive national system for the

registration of those offenders.” 42 U.S.C. § 16901. Congress could reasonably have

concluded that federally adjudicated sex offenders would pose an especially high danger

to the public if released from custody, or permitted to remain in the public on supervised

release, without being required to register as a sex offender. And, as suggested in

SORNA’s legislative history, Congress could have reasonably concluded that a



                                               22
reasonable number of such individuals would likely not comply with state sex-offender

registration requirements without a federal statute requiring them to do so.

       Congress’s desire to address these specific challenges, taken together with its

direct supervisory interest over Mr. Carel—a federal sex offender on supervised release

due to a conviction for a validly enacted federal criminal offense—supports the

conclusion that § 16913 “satisfies review for means-ends rationality.” Comstock, 130

U.S. at 1962 (quotations omitted); see also Carr, 130 S. Ct at 2239 (noting that “the

Federal Government has a direct supervisory interest” over persons convicted of federal

crimes”).

       Mr. Carel contends that § 16913 cannot be upheld as a valid exercise of

Congress’s authority under the Necessary and Proper Clause for several reasons. He first

argues that the Supreme Court’s reasoning in Comstock is inapplicable to this case

because the civil-commitment statute at issue in Comstock applies only to federal

offenders who are in federal custody.9 Mr. Carel is correct that, on its face, § 16913

applies to all federal sex offenders, even those not currently in federal custody or on

federal probation or supervised release, and that the scope of § 16913 is broader than the

statute at issue in Comstock. But as explained above, Mr. Carel was required to comply

with § 16913 as a condition of his supervised release and was still on supervised release

       9
        Mr. Carel offers several hypothetical scenarios in support of his position that
Congress does not have authority under the Necessary and Proper Clause to apply
§ 16913 to federal sex offenders. However, because Mr. Carel has asserted an as-applied
challenge, we do not address the hypothetical scenarios he has raised. See Scherer, 653
F.3d at 1245 (noting that in an as-applied challenge, plaintiffs “seek to vindicate their
own rights based on their own circumstances” (emphasis added)).

                                               23
when he was prosecuted for failing to comply with SORNA’s requirements. Because we

review Mr. Carel’s constitutional challenge to § 16913 as an as-applied challenge, we

need not and do not address whether application of § 16913 to a federal sex offender not

in federal custody or on federal supervised release would be a permissible exercise of

congressional authority under the Necessary and Proper Clause.

      Next, Mr. Carel argues that the federal government’s authority to safeguard the

public from dangers posed by federal offenders is limited to “safeguarding the public

from those in federal custody.” Aplt. Reply Br. at 30. But Comstock expressly

recognized that, pursuant to the Necessary and Proper Clause, “Congress has the implied

power to criminalize any conduct that might interfere with the exercise of an enumerated

power, and also the additional power to imprison people who violate those (inferentially

authorized) laws, and the additional power to provide for the safe and reasonable

management of those prisons, and the additional power to regulate those prisoners’

behavior even after their release.” 130 U.S. at 1964 (emphasis added).

      Finally, Mr. Carel argues that requiring him to register as a sex offender is too

attenuated from Congress’s authority to enact the statute under which he was originally

convicted. His argument appears to rely on a theory similar to one advanced by the

petitioner in Comstock—that “when legislating pursuant to the Necessary and Proper

Clause, Congress’s authority can be no more than one step removed from a specifically

enumerated power.” See 130 S. Ct. at 1963. But Comstock rejected this argument. See

Id. at 1964 (“[W]e must reject respondents’ argument that the Necessary and Proper

Clause permits no more than a single step between an enumerated power and an Act of

                                              24
Congress.”). We recognize that there are several logical steps between Congress’s

authority to criminalize sexual abuse of a minor in Indian country and its ability to

require a person convicted of that offense who is on supervised release to register as a sex

offender. However, because it is undisputed that Congress had authority to enact the

statute under which Mr. Carel was convicted and because § 16913 is reasonably adapted

to the effectuation of that statute and to Congress’s authority to impose nonpunitive civil

sanctions on those who violate that statute, the number of steps between Congress’s

action and its enumerated power is not determinative. See id.

                                IV.     CONCLUSION

       Based on Congress’s authority to enact Mr. Carel’s original statute of conviction,

we hold that Congress had corresponding Necessary and Proper Clause authority to

require Mr. Carel—a federal sex offender on supervised release for violating that

statute—to comply with § 16913’s registration provisions. We therefore reject Mr.

Carel’s as-applied challenge to § 16913 and affirm his conviction and sentence.




                                               25
