(Slip Opinion)              OCTOBER TERM, 2009                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

                       CARR v. UNITED STATES

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                THE SEVENTH CIRCUIT

    No. 08–1301. Argued February 24, 2010—Decided June 1, 2010
Enacted in 2006, the Sex Offender Registration and Notification Act
 (SORNA) makes it a federal crime for, inter alia, any person (1) who
 “is required to register under [SORNA],” and (2) who “travels in in
 terstate or foreign commerce,” to (3) “knowingly fai[l] to register or
 update a registration,” 18 U. S. C. §2250(a). Before SORNA’s enact
 ment, petitioner Carr, a registered sex offender in Alabama, relocated
 to Indiana without complying with the latter State’s registration re
 quirements. Carr was indicted under §2250 post-SORNA. The Fed
 eral District Court denied Carr’s motion to dismiss, which asserted
 that the §2250 prosecution would violate the Constitution’s Ex Post
 Facto Clause because he had traveled to Indiana before SORNA’s ef
 fective date. Carr then pleaded guilty and was sentenced to prison.
 Affirming the conviction, the Seventh Circuit held that §2250 does
 not require that a defendant’s travel postdate SORNA and that reli
 ance on a defendant’s pre-SORNA travel poses no ex post facto prob
 lem so long as the defendant had a reasonable time to register post-
 SORNA but failed to do so, as had Carr.
Held: Section 2250 does not apply to sex offenders whose interstate
 travel occurred before SORNA’s effective date. Pp. 5–18.
    (a) The Court rejects the Government’s view that §2250(a) requires
 a sex-offense conviction, subsequent interstate travel, and then a
 failure to register, and that only the last of these events must occur
 after SORNA took effect. The Court instead accepts Carr’s interpre
 tation that the statute does not impose liability unless a person, after
 becoming subject to SORNA’s registration requirements, travels
 across state lines and then fails to register. That interpretation bet
 ter accords with §2250(a)’s text, the first element of which can only be
 satisfied when a person “is required to register under SORNA.”
2                       CARR v. UNITED STATES

                                  Syllabus

    §2250(a)(1). That §2250 sets forth the travel requirement in the pre
    sent tense (“travels”) rather than in the past or present perfect
    (“traveled” or “has traveled”) reinforces this conclusion. See, e.g.,
    United States v. Wilson, 503 U. S. 329, 333. And because the Dic
    tionary Act’s provision that statutory “words used in the present
    tense include the future as well as the present,” 1 U. S. C. §1, implies
    that the present tense generally does not include the past, regulating
    a person who “travels” is not readily understood to encompass a per
    son whose only travel occurred before the statute took effect. Indeed,
    there appears to be no instance in which this Court has construed a
    present-tense verb in a criminal law to reach preenactment conduct.
    The statutory context also supports a forward-looking construction of
    “travels.” First, the word “travels” is followed in §2250(a)(2)(B) by a
    series of other present tense verbs—“enters or leaves, or resides.” A
    statute’s “undeviating use of the present tense” is a “striking
    indic[ator]” of its “prospective orientation.” Gwaltney of Smithfield,
    Ltd. v. Chesapeake Bay Foundation, Inc., 484 U. S. 49, 59. Second,
    the other elements of a §2250 violation are similarly set forth in the
    present tense: Sections 2250(a)(1) and (a)(3) refer, respectively, to
    any person who “is required to register under [SORNA]” and who
    “knowingly fails to register or update a registration.” (Emphasis
    added.) Had Congress intended preenactment conduct to satisfy
    §2250’s first two requirements but not the third, it presumably would
    have varied the verb tenses, as it has in numerous other federal stat
    utes. Pp. 5–11.
        (b) The Government’s two principal arguments for construing the
    statute to cover pre-SORNA travel are unpersuasive. Pp. 11–18.
           (1) The claim that such a reading avoids an “anomaly” in the
    statute’s coverage of federal versus state sex offenders is rejected.
    Section 2250 imposes criminal liability on two categories of persons
    who fail to adhere to SORNA’s registration requirements: any person
    who is a sex offender “by reason of a conviction under Federal law
    . . . ,” §2250(a)(2)(A), and any other person required to register under
    SORNA who “travels in interstate or foreign commerce,”
    §2250(a)(2)(B). The Government’s assertion that §2250(a)(2)’s juris
    dictional reach should have comparable breadth as applied to both
    federal and state sex offenders is little more than ipse dixit. It is en
    tirely reasonable for Congress to have assigned the Federal Govern
    ment a special role in ensuring compliance with SORNA’s registra
    tion requirements by federal sex offenders, who typically would have
    spent time under federal criminal supervision. It is similarly reason
    able for Congress to have given the States primary responsibility for
    supervising and ensuring compliance among state sex offenders and
    to have subjected such offenders to federal criminal liability only
                     Cite as: 560 U. S. ____ (2010)                     3

                                Syllabus

  when, after SORNA’s enactment, they use interstate commerce
  channels to evade a State’s reach. The Seventh Circuit erred in
  analogizing §2250 to 18 U. S. C. §922(g), which prohibits convicted
  felons from “possess[ing] in . . . commerc[e] any firearm or ammuni
  tion.” According to the lower court, §2250(a), like §922(g), uses
  movement in interstate commerce as a jurisdictional element to es
  tablish a constitutional predicate for the statute, not to create a tem
  poral requirement. However, the proper analogy here is not between
  the travel of a sex offender and the movement of a firearm, but be
  tween the sex offender who “travels” and the convicted felon who
  “possesses.” The act of travel by a convicted sex offender may serve
  as a jurisdictional predicate for §2250, but it is also, like the act of
  possession, the very conduct at which Congress took aim. Pp. 11–14.
        (2) Also unavailing is the Government’s invocation of one of
  SORNA’s purposes, to locate sex offenders who failed to abide by
  their registration obligations. The Government’s argument confuses
  SORNA’s general goal with §2250’s specific purpose. Section 2250 is
  not a stand-alone response to the problem of missing sex offenders; it
  is embedded in a broader statutory scheme enacted to address defi
  ciencies in prior law that had enabled sex offenders to slip through
  the cracks. By facilitating the collection of sex-offender information
  and its dissemination among jurisdictions, these other provisions, not
  §2250, stand at the center of Congress’ effort to account for missing
  sex offenders. While subjecting pre-SORNA travelers to punishment
  under §2250 may well be consistent with the aim of finding missing
  sex offenders, a contrary construction in no way frustrates that broad
  goal. Taking account of SORNA’s overall structure, there is little
  reason to doubt that Congress intended §2250 to do exactly what it
  says: to subject to federal prosecution sex offenders who elude
  SORNA’s registration requirements by traveling in interstate com
  merce. Pp. 14–17.
        (3) None of the legislative materials the Government cites as evi
  dence of SORNA’s purpose calls this reading into question. To the
  contrary, the House Judiciary Committee’s Report suggests not only
  that a prohibition on postenactment travel is consonant with Con
  gress’ goals, but also that it is the rule Congress in fact chose to
  adopt. Pp. 17–18.
     (c) Because §2250 liability cannot be predicated on pre-SORNA
  travel, the Court need not address whether the statute violates the
  Ex Post Facto Clause. P. 18.
551 F. 3d 578, reversed and remanded.

  SOTOMAYOR, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and STEVENS, KENNEDY, and BREYER, JJ., joined, and in which
4                      CARR v. UNITED STATES

                                Syllabus

SCALIA, J., joined except for Part III–C. SCALIA, J., filed an opinion con
curring in part and concurring in the judgment. ALITO, J., filed a dis
senting opinion, in which THOMAS and GINSBURG, JJ., joined.
                        Cite as: 560 U. S. ____ (2010)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 08–1301
                                   _________________


  THOMAS CARR, PETITIONER v. UNITED STATES
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

           APPEALS FOR THE SEVENTH CIRCUIT

                                 [June 1, 2010]


   JUSTICE SOTOMAYOR delivered the opinion of the Court.
   Since 1994, federal law has required States, as a condi
tion for the receipt of certain law enforcement funds, to
maintain federally compliant systems for sex-offender
registration and community notification. In an effort to
make these state schemes more comprehensive, uniform,
and effective, Congress in 2006 enacted the Sex Offender
Registration and Notification Act (SORNA or Act) as part
of the Adam Walsh Child Protection and Safety Act, Pub.
L. 109–248, Tit. I, 120 Stat. 590. Among its provisions,
the Act established a federal criminal offense covering,
inter alia, any person who (1) “is required to register
under [SORNA],” (2) “travels in interstate or foreign com
merce,” and (3) “knowingly fails to register or update a
registration.” 18 U. S. C. §2250(a). At issue in this case is
whether §2250 applies to sex offenders whose interstate
travel occurred prior to SORNA’s effective date and, if so,
whether the statute runs afoul of the Constitution’s prohi
bition on ex post facto laws. See Art. I, §9, cl. 3. Liability
under §2250, we hold, cannot be predicated on pre-SORNA
travel. We therefore do not address the ex post facto
question.
2                 CARR v. UNITED STATES


                     Opinion of the Court 


                              I

   In May 2004, petitioner Thomas Carr pleaded guilty in
Alabama state court to first-degree sexual abuse. He was
sentenced to 15 years’ imprisonment, with all but two
years suspended. Receiving credit for time previously
served, Carr was released on probation on July 3, 2004,
and he registered as a sex offender as required by Ala
bama law.
   In late 2004 or early 2005, prior to SORNA’s enactment,
Carr relocated from Alabama to Indiana. He did not
comply with Indiana’s sex-offender registration require
ments. In July 2007, Carr came to the attention of law
enforcement in Fort Wayne, Indiana, following his in
volvement in a fight.
   On August 22, 2007, federal prosecutors filed an indict
ment in the United States District Court for the Northern
District of Indiana charging Carr with failing to register in
violation of §2250. Carr moved to dismiss the indictment,
asserting that because he traveled to Indiana prior to
SORNA’s effective date, it would violate the Ex Post Facto
Clause to prosecute him under §2250. The District Court
denied Carr’s motion, and Carr entered a conditional
guilty plea, preserving his right to appeal. He received a
30-month prison sentence.
   The United States Court of Appeals for the Seventh
Circuit consolidated Carr’s appeal with that of a similarly
situated defendant, who, in addition to raising an ex post
facto claim, asserted that §2250, by its terms, does not
apply to persons whose interstate travel preceded
SORNA’s enactment. Beginning with the statutory argu
ment, the Court of Appeals held that §2250 “does not
require that the defendant’s travel postdate the Act.”
United States v. Dixon, 551 F. 3d 578, 582 (2008). The
court relied principally on its understanding of SORNA’s
underlying purpose:
                  Cite as: 560 U. S. ____ (2010)            3

                      Opinion of the Court

    “The evil at which [the Act] is aimed is that convicted
    sex offenders registered in one state might move to
    another state, fail to register there, and thus leave the
    public unprotected. The concern is as acute in a case
    in which the offender moved before the Act was
    passed as in one in which he moved afterward.” Ibid.
    (citation omitted).
The court drew an analogy to 18 U. S. C. §922(g), which
prohibits convicted felons from “possess[ing] in or affecting
commerc[e] any firearm or ammunition.” “The danger
posed by such a felon is unaffected by when the gun
crossed state lines . . . , and so it need not have crossed
after the statute was passed.” 551 F. 3d, at 582 (citing
Scarborough v. United States, 431 U. S. 563 (1977)).
According to the court, §2250(a), like §922(g), uses move
ment in interstate commerce as a jurisdictional element
“to establish a constitutional predicate for the statute . . .
rather than to create a temporal requirement.” 551 F. 3d,
at 583.
   Reading §2250 to encompass pre-SORNA travel, the
Seventh Circuit recognized, created a conflict with the
Tenth Circuit’s decision in United States v. Husted, 545
F. 3d 1240 (2008). In holding that §2250’s coverage “is
limited to those individuals who travel in interstate com
merce after the Act’s effective date,” the Tenth Circuit
emphasized “Congress’s use of the present tense form of
the verb ‘to travel’ . . . , which according to ordinary Eng
lish grammar, does not refer to travel that has already
occurred.” Id., at 1243–1244. Rejecting this analysis, the
Seventh Circuit characterized Congress’ choice of tenses
as “ ‘not very revealing.’ ” 551 F. 3d, at 583 (quoting Scar
borough, 431 U. S., at 571).
   Having dispensed with the statutory question, the
Seventh Circuit considered the claim of Carr and his co
appellant that predicating a §2250 prosecution on pre
4                     CARR v. UNITED STATES

                          Opinion of the Court

SORNA travel violates the Ex Post Facto Clause. Reliance
on a defendant’s pre-SORNA travel, the court concluded,
poses no ex post facto problem so long as the defendant
had “reasonable time” to register after SORNA took effect
but failed to do so. 551 F. 3d, at 585. Noting that Carr
remained unregistered five months after SORNA became
applicable to him, the Seventh Circuit affirmed his convic
tion. Id., at 586–587. The court reversed the conviction of
Carr’s co-appellant, finding that he had not been given a
sufficient grace period to register.
   In view of the division among the Circuits as to the
meaning of §2250’s “travel” requirement,1 we granted
certiorari, 557 U. S. __ (2009), to decide the statute’s
applicability to pre-SORNA travel and, if necessary, to
consider the statute’s compliance with the Ex Post Facto
Clause.2
——————
  1 While the Seventh and Tenth Circuits have confronted the question

directly, other Circuits have also touched on it. Aligning itself with the
Seventh Circuit, the Eleventh Circuit has analogized 18 U. S. C.
§2250(a) to the felon-in-possession statute, §922(g), and applied it to a
sex offender who traveled before SORNA became applicable to him.
United States v. Dumont, 555 F. 3d 1288, 1291–1292 (2009) (per cu
riam). In contrast, the Eighth Circuit has stated in dictum that
§2250(a) “punishes convicted sex offenders who travel in interstate
commerce after the enactment of SORNA.” United States v. May, 535
F. 3d 912, 920 (2008) (emphasis added).
  2 There is a separate conflict among the Courts of Appeals as to when

SORNA’s registration requirements became applicable to persons
convicted of sex offenses prior to the statute’s enactment. Several
Circuits, including the Seventh, have taken the position that the Act
did not apply to such sex offenders until the Attorney General provided
for their inclusion by issuing an interim regulation, 28 CFR §72.3, 72
Fed. Reg. 8897, on February 28, 2007. See, e.g., United States v.
Hatcher, 560 F. 3d 222, 226–229 (CA4 2009); United States v. Cain, 583
F. 3d 408, 414–419 (CA6 2009); United States v. Dixon, 551 F. 3d 578,
582 (CA7 2008) (case below); United States v. Madera, 528 F. 3d 852,
857–859 (CA11 2008) (per curiam). Other Circuits have held that
persons with pre-SORNA sex-offense convictions became subject to the
Act’s registration requirements upon the statute’s enactment in July
                    Cite as: 560 U. S. ____ (2010)                   5

                         Opinion of the Court

                            II
  As relevant here, §2250 provides:
        “(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 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 registra
     tion 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.”
For a defendant to violate this provision, Carr and the
Government agree, the statute’s three elements must “be
satisfied in sequence, culminating in a post-SORNA fail

——————
2006. See, e.g., May, 535 F. 3d, at 915–919; United States v. Hinckley,
550 F. 3d 926, 929–935 (CA10 2008). Because Carr traveled from
Alabama to Indiana before both the enactment of SORNA and the
Attorney General’s regulation, we have no occasion to consider whether
a pre-SORNA sex offender whose travel and failure to register occurred
between July 2006 and February 2007 is subject to liability under
§2250, and we express no view on that question. We similarly express
no view as to whether §72.3 was properly promulgated—a question that
has also divided the Circuits. Compare Cain, 583 F. 3d, at 419–424
(holding that the Attorney General lacked good cause for issuing the
interim regulation without adhering to the notice-and-comment and
publication requirements of the Administrative Procedure Act (APA)),
with United States v. Dean, No. 09–13115, 2010 WL 1687618, *3–*8
(CA11, Apr. 28, 2010) (finding no APA violation); United States v.
Gould, 568 F. 3d 459, 469–470 (CA4 2009) (same).
6                     CARR v. UNITED STATES

                         Opinion of the Court

ure to register.” Brief for United States 13; see also Reply
Brief for Petitioner 4, 7, n. 6. A sequential reading, the
parties recognize, helps to assure a nexus between a de
fendant’s interstate travel and his failure to register as a
sex offender. Persons convicted of sex offenses under state
law who fail to register in their State of conviction would
otherwise be subject to federal prosecution under §2250
even if they had not left the State after being convicted—
an illogical result given the absence of any obvious federal
interest in punishing such state offenders.3
   While both parties accept that the elements of §2250
should be read sequentially, they disagree on the event
that sets the sequence in motion. In the Government’s
view, the statute is triggered by a sex-offense conviction,
which must be followed by interstate travel, and then a
failure to register under SORNA. Only the last of these
events, the Government maintains, must occur after
SORNA took effect; the predicate conviction and the travel
may both have predated the statute’s enactment. Carr, in
contrast, asserts that the statutory sequence begins when
a person becomes subject to SORNA’s registration re
quirements. The person must then travel in interstate
commerce and thereafter fail to register. All of these
events, Carr avers, necessarily postdate SORNA’s enact
ment because a sex offender could not have been required
to register under SORNA until SORNA became the law.
   Carr’s interpretation better accords with the statutory
text. By its terms, the first element of §2250(a) can only
be satisfied when a person “is required to register under
the Sex Offender Registration and Notification Act.”
§2250(a)(1) (emphasis added). In an attempt to reconcile
its preferred construction with the words of the statute,
——————
  3 For persons convicted of sex offenses under federal or Indian tribal

law, interstate travel is not a prerequisite to §2250 liability. See
§2250(a)(2)(A).
                      Cite as: 560 U. S. ____ (2010)                     7

                          Opinion of the Court

the Government insists that this language is merely “a
shorthand way of identifying those persons who have a
[sex-offense] conviction in the classes identified by
SORNA.” Brief for United States 19–20. To reach this
conclusion, the Government observes that another provi
sion of SORNA, 42 U. S. C. §16913(a), states that the Act’s
registration requirements apply to “sex offender[s].” A
“sex offender” is elsewhere defined as “an individual who
was convicted of a sex offense.” §16911(1). Thus, as the
Government would have it, Congress used 12 words and
two implied cross-references to establish that the first
element of §2250(a) is that a person has been convicted of
a sex offense. Such contortions can scarcely be called
“shorthand.” It is far more sensible to conclude that Con
gress meant the first precondition to §2250 liability to be
the one it listed first: a “require[ment] to register under
[SORNA].” Once a person becomes subject to SORNA’s
registration requirements, which can occur only after the
statute’s effective date, that person can be convicted under
§2250 if he thereafter travels and then fails to register.4
  That §2250 sets forth the travel requirement in the
present tense (“travels”) rather than in the past or present
perfect (“traveled” or “has traveled”) reinforces the conclu
——————
  4 Offering  a variation on the Government’s argument, the dissent
contends that, “[i]n accordance with current drafting conventions,
§2250(a) speaks, not as of the time when the law went into effect, but
as of the time when the first act necessary for conviction is committed.”
Post, at 7 (opinion of ALITO, J.). This occurs, the dissent maintains,
“when an individual is convicted of a qualifying sex offense, for it is
that act that triggers the requirement to register under SORNA.” Ibid.
The dissent’s account cannot be squared with the statutory text. “[T]he
first act necessary for conviction” under §2250(a) is not a predicate sex
offense conviction. It is a requirement “to register under [SORNA].”
§2250(a)(1). Thus, even if the dissent is correct that legislative drafters
do not invariably use the moment of enactment to mark the dividing
line between covered and uncovered acts, they have clearly done so
here.
8                     CARR v. UNITED STATES

                          Opinion of the Court

sion that preenactment travel falls outside the statute’s
compass. Consistent with normal usage, we have fre
quently looked to Congress’ choice of verb tense to ascer
tain a statute’s temporal reach. See, e.g., United States v.
Wilson, 503 U. S. 329, 333 (1992) (“Congress’ use of a verb
tense is significant in construing statutes”); Gwaltney of
Smithfield, Ltd. v. Chesapeake Bay Foundation, Inc., 484
U. S. 49, 57 (1987) (“Congress could have phrased its
requirement in language that looked to the past . . . , but it
did not choose this readily available option”); Barrett v.
United States, 423 U. S. 212, 216 (1976) (observing that
Congress used the present perfect tense to “denot[e] an act
that has been completed”). The Dictionary Act also as
cribes significance to verb tense. It provides that, “[i]n
determining the meaning of any Act of Congress, unless
the context indicates otherwise[,] . . . words used in the
present tense include the future as well as the present.” 1
U. S. C. §1. By implication, then, the Dictionary Act in
structs that the present tense generally does not include
the past. Accordingly, a statute that regulates a person
who “travels” is not readily understood to encompass a
person whose only travel occurred before the statute took
effect. Indeed, neither the Government nor the dissent
identifies any instance in which this Court has construed
a present-tense verb in a criminal law to reach preenact
ment conduct.5
——————
    5 The
        Court of Appeals quoted a Ninth Circuit decision for the propo
sition that “ ‘the present tense is commonly used to refer to past, pre
sent, and future all at the same time.’ ” 551 F. 3d, at 583 (quoting
Coalition for Clean Air v. Southern Cal. Edison Co., 971 F. 2d 219, 225
(CA9 1992)). Neither court offered examples of such usage. Perhaps,
as the Dictionary Act itself recognizes, there may be instances in which
“context” supports this sort of omnitemporality, but it is not the typical
understanding of the present tense in either normal discourse or
statutory construction. Taken in context, the word “travels” as it
appears in §2250 is indistinguishable from the present-tense verbs that
appear in myriad other criminal statutes to proscribe conduct on a
                     Cite as: 560 U. S. ____ (2010)                     9

                          Opinion of the Court

   In this instance, the statutory context strongly supports
a forward-looking construction of “travels.” First, the
word “travels” is followed in §2250(a)(2)(B) by a series of
other present tense verbs—“enters or leaves, or resides in,
Indian country.” (Emphasis added.) This Court has previ
ously described a statute’s “undeviating use of the present
tense” as a “striking indic[ator]” of its “prospective orien
tation.” Gwaltney, 484 U. S., at 59. The Seventh Circuit
thought otherwise, reasoning that it would “mak[e] no
sense” for “a sex offender who has resided in Indian coun
try since long before the Act was passed [to be] subject to
the Act but not someone who crossed state lines before the
Act was passed.” 551 F. 3d, at 583. As a textual matter,
however, it is the Seventh Circuit’s approach that makes
little sense: If “travels” means “traveled” (i.e., a person
“travels” if he crossed state lines before SORNA’s enact
ment), then the only way to avoid an incongruity among
neighboring verbs would be to construe the phrase “re
sides i[n] Indian country” to encompass persons who once
resided in Indian country but who left before SORNA’s
enactment and have not since returned—an implausible
reading that neither the Seventh Circuit, nor the Govern
ment, nor the dissent endorses.
   Second, the other elements of a §2250 violation are
similarly set forth in the present tense.            Sections
2250(a)(1) and (a)(3) refer, respectively, to any person who
“is required to register under [SORNA]” and who “know
ingly fails to register or update a registration as required
——————
prospective basis. Examining a criminal law with a travel element
similar to the one at issue here, the Ninth Circuit itself recently agreed
that “the present tense verb ‘travels,’ most sensibly read, does not refer
to travel that occurred in the past—that is, before the enactment of the
statute.” United States v. Jackson, 480 F. 3d 1014, 1019 (CA9 2007)
(interpreting 18 U. S. C. §2423(c), which imposes criminal penalties on
“[a]ny United States citizen . . . who travels in foreign commerce, and
engages in any illicit sexual conduct with another person”).
10                    CARR v. UNITED STATES

                          Opinion of the Court

by [SORNA].” (Emphasis added.) The Government ac
cepts that this last element—a knowing failure to register
or update a registration—must postdate SORNA’s enact
ment. Had Congress intended preenactment conduct to
satisfy the first two requirements of §2250 but not the
third, it presumably would have varied the verb tenses to
convey this meaning. Indeed, numerous federal statutes
use the past-perfect tense to describe one or more ele
ments of a criminal offense when coverage of preenact
ment events is intended.         See, e.g., 18 U. S. C. A.
§249(a)(2)(B)(iii) (Supp. 2010) (proscribing hate crimes in
which “the defendant employs a firearm, dangerous
weapon, explosive or incendiary device, or other weapon
that has traveled in interstate or foreign commerce” (em
phasis added)); 18 U. S. C. §922(g)(9) (2006 ed.) (proscrib
ing firearm possession or transport by any person “who
has been convicted” of a felony or a misdemeanor crime of
domestic violence (emphasis added)); §2252(a)(2) (2006
ed., Supp. II) (making it unlawful for any person to receive
or distribute a visual depiction of a minor engaging in
sexually explicit conduct that “has been mailed, or has
been shipped or transported in or affecting interstate or
foreign commerce” (emphasis added)). The absence of
similar phrasing here provides powerful evidence that
§2250 targets only postenactment travel.6
——————
   6 The dissent identifies several “SORNA provisions that plainly use

the present tense to refer to events that . . . may have occurred before
SORNA took effect.” Post, at 10. All of these examples appear in 42
U. S. C. §16911, a definitional section that merely elucidates the
meaning of certain statutory terms and proscribes no conduct. All but
two of the provisions, moreover, rely on the term “sex offender,” which
§16911(1) defines to mean “an individual who was convicted of a sex
offense.” (Emphasis added.) The remaining provisions are §16911(7),
which simply uses “involves” rather than “involved” to define whether a
prior conviction qualifies as a “specified offense against a minor,” and
§16911(8), which makes plain that its present-tense reference to an
offender’s age refers to age “at the time of the offense.” These examples
                     Cite as: 560 U. S. ____ (2010) 
                  11

                          Opinion of the Court 


                             III 

  Echoing the Seventh Circuit’s assessment that Con
gress’ use of present-tense verbs in §2250 is “not very
revealing,” Brief for United States 17, the Government
offers two principal arguments for construing the statute
to cover pre-SORNA travel: First, such a reading avoids
an “anomaly” in the statute’s coverage of federal versus
state sex offenders; and second, it “better effectuates the
statutory purpose.” Id., at 22 (capitalization omitted).
Neither argument persuades us to adopt the Government’s
strained reading of the statutory text.
                             A
  Section 2250 imposes criminal liability on two categories
of persons who fail to adhere to SORNA’s registration
requirements: any person who is a sex offender “by reason
of a conviction under Federal law . . . , the law of the
District of Columbia, Indian tribal law, or the law
of any territory or possession of the United States,”
§2250(a)(2)(A), and any other person required to register
under SORNA who “travels in interstate or foreign com
merce, or enters or leaves, or resides in, Indian country,”
§2250(a)(2)(B). According to the Government, these cate
gories correspond to “two alternate sources of power to
achieve Congress’s aim of broadly registering sex offend
ers.” Id., at 22. Placing pre-SORNA travelers within the
statute’s coverage, the Government maintains, “ensures
that the jurisdictional reach of Section 2250(a)(2) has a
——————
thus provide scant support for the proposition that §2250 uses “travels”
to refer to pre-SORNA travel. Given the well-established presumption
against retroactivity and, in the criminal context, the constitutional bar
on ex post facto laws, it cannot be the case that a statutory prohibition
set forth in the present tense applies by default to acts completed before
the statute’s enactment. See Johnson v. United States, 529 U. S. 694,
701 (2000) (“Absent a clear statement of that intent, we do not give
retroactive effect to statutes burdening private interests”).
12                 CARR v. UNITED STATES

                      Opinion of the Court

comparable breadth as applied to both federal and state
sex offenders.” Id., at 21.
   The Government’s pronouncement that §2250 should
have an “equally broad sweep” with respect to federal and
state offenders, id., at 22, is little more than ipse dixit.
Had Congress intended to subject any unregistered state
sex offender who has ever traveled in interstate commerce
to federal prosecution under §2250, it easily could have
adopted language to that effect. That it declined to do so
indicates that Congress instead chose to handle federal
and state sex offenders differently. There is nothing
“anomal[ous]” about such a choice. To the contrary, it is
entirely reasonable for Congress to have assigned the
Federal Government a special role in ensuring compliance
with SORNA’s registration requirements by federal sex
offenders—persons who typically would have spent time
under federal criminal supervision. It is similarly reason
able for Congress to have given the States primary re
sponsibility for supervising and ensuring compliance
among state sex offenders and to have subjected such
offenders to federal criminal liability only when, after
SORNA’s enactment, they use the channels of interstate
commerce in evading a State’s reach.
   In this regard, it is notable that the federal sex-offender
registration laws have, from their inception, expressly
relied on state-level enforcement. Indeed, when it initially
set national standards for state sex-offender registration
programs in 1994, Congress did not include any federal
criminal liability. Congress instead conditioned certain
federal funds on States’ adoption of “criminal penalties” on
any person “required to register under a State program . . .
who knowingly fails to so register and keep such registra
tion current.” Jacob Wetterling Crimes Against Children
and Sexually Violent Offender Registration Act, Pub. L.
103–322, Tit. XVII, §170101(c), 108 Stat. 2041, 42 U. S. C.
§14071(d). Two years later, Congress supplemented state
                     Cite as: 560 U. S. ____ (2010)                    13

                          Opinion of the Court

enforcement mechanisms by subjecting to federal prosecu
tion any covered sex offender who “changes address to a
State other than the State in which the person resided at
the time of the immediately preceding registration” and
“knowingly fails to” register as required. Pam Lychner
Sexual Offender Tracking and Identification Act of 1996,
Pub. L. 104–236, §2, 110 Stat. 3095, 3096, 42 U. S. C.
§§14072(g)(3), (i).7 The prospective orientation of this
provision is apparent. No statutory gap necessitated
coverage of unregistered offenders who “change[d] ad
dress” before the statute’s enactment; the prosecution of
such persons remained the province of the States.
   In enacting SORNA, Congress preserved this basic
allocation of enforcement responsibilities. To strengthen
state enforcement of registration requirements, Congress
established, as a funding condition, that “[e]ach jurisdic
tion, other than a Federally recognized Indian tribe, shall
provide a criminal penalty that includes a maximum term
of imprisonment that is greater than 1 year for the failure
of a sex offender to comply with the requirements of this
subchapter.” §16913(e).8 Meanwhile, Congress in §2250
exposed to federal criminal liability, with penalties of up
to 10 years’ imprisonment, persons required to register
under SORNA over whom the Federal Government has a
direct supervisory interest or who threaten the efficacy of
the statutory scheme by traveling in interstate commerce.
——————
  7 Pre-SORNA    law also exposed to federal criminal liability any person
whose State “ha[d] not established a minimally sufficient sexual
offender registration program” and who was thus required to register
with the Federal Bureau of Investigation (FBI). See 42 U. S. C.
§§14072(c), (g)(2), (i). SORNA does not include a similar FBI registra
tion requirement, presumably because, by the time of the statute’s
enactment, “every State . . . had enacted some” type of registration
system. Smith v. Doe, 538 U. S. 84, 90 (2003).
   8 The law in Indiana, Carr’s State of residence, makes the failure to

register a Class D felony, which carries a prison term of up to three
years’ imprisonment. Ind. Code §§11–8–8–17(a), 35–50–2–7(a) (2009).
14                 CARR v. UNITED STATES

                      Opinion of the Court

   Understanding the act of travel as an aspect of the harm
Congress sought to punish serves to distinguish §2250
from the felon-in-possession statute to which the Seventh
Circuit analogized. See 551 F. 3d, at 582–583. In Scar
borough, this Court held that a prior version of the stat
ute, which imposed criminal liability on any convicted
felon who “ ‘possesses . . . in commerce or affecting com
merce . . . any firearm,’ ” 431 U. S., at 564 (quoting 18
U. S. C. App. §1202(a) (1970 ed.)), did not require the
Government to prove postenactment movement of the
firearm across state lines. According to the Court, Con
gress had given “no indication of any concern with either
the movement of the gun or the possessor or with the time
of acquisition.” 431 U. S., at 572. Its aim was simply “to
keep guns out of the hands of” convicted felons, ibid., and,
by using the phrase “in commerce or affecting commerce,”
it invoked the full breadth of its Commerce Clause author
ity to achieve that end. No one in Scarborough disputed,
however, that the act of possession had to occur post
enactment; a felon who “possess[ed]” a firearm only pre
enactment was plainly outside the statute’s sweep. In this
case, the proper analogy is not, as the Seventh Circuit
suggested, between the travel of a sex offender and the
movement of a firearm; it is between the sex offender who
“travels” and the convicted felon who “possesses.” The act
of travel by a convicted sex offender may serve as a juris
dictional predicate for §2250, but it is also, like the act of
possession, the very conduct at which Congress took aim.
                              B
  In a final effort to justify its position, the Government
invokes one of SORNA’s underlying purposes: to locate sex
offenders who had failed to abide by their registration
obligations.   SORNA, the Government observes, was
motivated at least in part by Congress’ concern about
these “missing” sex offenders—a problem the House
                     Cite as: 560 U. S. ____ (2010)                    15

                          Opinion of the Court

Committee on the Judiciary expressly linked to interstate
travel: “The most significant enforcement issue in the sex
offender program is that over 100,000 sex offenders, or
nearly one-fifth in the Nation[,] are ‘missing,’ meaning
they have not complied with sex offender registration
requirements. This typically occurs when the sex offender
moves from one State to another.” H. R. Rep. No. 109–
218, pt. 1, p. 26 (2005). The goal of tracking down missing
sex offenders, the Government maintains, “is surely better
served by making Section 2250 applicable to them in their
new States of residence immediately than by waiting for
them to travel in interstate commerce and fail to register
yet again.” Brief for United States 23–24. The Court of
Appeals expressed a similar view. See 551 F. 3d, at 582.9
   The Government’s argument confuses a general goal of
SORNA with the specific purpose of §2250. Section 2250
is not a stand-alone response to the problem of missing sex
——————
   9 Also making this point, the dissent maintains that “[i]nterpreting

§2250(a)(2)(B) to reach only postenactment travel severely impairs
§2250(a)’s effectiveness” by “plac[ing] beyond the reach of the federal
criminal laws” “the many sex offenders who had managed to avoid pre
existing registration regimes.” Post, at 14. The dissent sees “no appar
ent reason why Congress would have wanted to impose such a require
ment.” Ibid. Yet the dissent approves an even greater impairment.
Addressing a dispute we leave unresolved, see n. 2, supra, the dissent
would hold that, in enacting SORNA, “Congress remained neutral on
the question whether the Act reaches those with pre-SORNA sex
offense convictions.” Post, at 10. The dissent’s view, in other words, is
that SORNA does not apply of its own force to any sex offenders con
victed prior to the statute’s enactment—a reading wholly inconsistent
with the dissent’s description of SORNA as “a response to a dangerous
gap in the then-existing sex-offender-registration laws.” Post, at 13. If,
as the dissent accepts, Congress left open the possibility that no preen
actment offenders would face liability under §2250, then it is certainly
not unreasonable to conclude that Congress limited the statute’s
coverage to offenders who travel after its enactment. Indeed, it is
strange to think that Congress might have enacted a statute that
declined to cover pre-SORNA offenders but nevertheless covered pre-
SORNA travel.
16                CARR v. UNITED STATES

                     Opinion of the Court

offenders; it is embedded in a broader statutory scheme
enacted to address the deficiencies in prior law that had
enabled sex offenders to slip through the cracks. See 42
U. S. C. §16901 (“Congress in this chapter establishes a
comprehensive national system for the registration of [sex]
offenders”). Among its many provisions, SORNA instructs
States to maintain sex-offender registries that compile an
array of information about sex offenders, §16914; to make
this information publicly available online, §16918; to share
the information with other jurisdictions and with the
Attorney General for inclusion in a comprehensive na
tional sex-offender registry, §§16919–16921; and to “pro
vide a criminal penalty that includes a maximum term of
imprisonment that is greater than 1 year for the failure of
a sex offender to comply with the requirements of this
subchapter,” §16913(e). Sex offenders, in turn, are re
quired to “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 stu
dent,” §16913(a), and to appear in person periodically to
“allow the jurisdiction to take a current photograph, and
verify the information in each registry in which that of
fender is required to be registered,” §16916. By facilitat
ing the collection of sex-offender information and its dis
semination among jurisdictions, these provisions, not
§2250, stand at the center of Congress’ effort to account for
missing sex offenders.
   Knowing that Congress aimed to reduce the number of
noncompliant sex offenders thus tells us little about the
specific policy choice Congress made in enacting §2250.
While subjecting pre-SORNA travelers to punishment
under §2250 may well be consistent with the aim of find
ing missing sex offenders, a contrary construction in no
way frustrates that broad goal.         Taking account of
SORNA’s overall structure, we have little reason to doubt
that Congress intended §2250 to do exactly what it says:
                     Cite as: 560 U. S. ____ (2010)                   17

                          Opinion of the Court

to subject to federal prosecution sex offenders who elude
SORNA’s registration requirements by traveling in inter
state commerce. Cf. Mertens v. Hewitt Associates, 508
U. S. 248, 261 (1993) (“[V]ague notions of a statute’s ‘basic
purpose’ are . . . inadequate to overcome the words of its
text regarding the specific issue under consideration”).
                                C
   None of the legislative materials the Government cites
as evidence of SORNA’s purpose calls this reading into
question. To the contrary, the report of the House Judici
ary Committee suggests not only that a prohibition on
postenactment travel is consonant with Congress’ goals,
but also that it is the rule Congress in fact chose to adopt.
As the Government acknowledges, the bill under consid
eration by the Committee contained a version of §2250
that “would not have reached pre-enactment interstate
travel.” Brief for United States 24, n. 9. This earlier
version imposed federal criminal penalties on any person
who “receives a notice from an official that such person is
required to register under [SORNA] and . . . thereafter
travels in interstate or foreign commerce, or enters or
leaves Indian country.” H. R. Rep. No. 109–218, pt. 1, at
9; see also id., at 26 (“[S]ex offenders will now face Federal
prosecution . . . if they cross a State line and fail to comply
with the sex offender registration and notification re
quirements contained in the legislation”). Yet this did not
stop the Committee from describing its legislation as a
solution to the problem of missing sex offenders. See id.,
at 23–24, 26, 45–46. The Government identifies nothing
in the legislative record to suggest that, in modifying this
language during the course of the legislative process,
Congress intended to alter the statute’s temporal sweep.10
——————
  10 Among other changes, Congress eliminated the language that con

ditioned liability on proof of notice, and it removed the word “thereaf
ter,” presumably as redundant in light of the sequential structure of the
18                 CARR v. UNITED STATES

                     Opinion of the Court

At the very least, the close correspondence between the
Committee’s discussion of missing sex offenders and its
recognition of the travel element’s prospective application
would seem to confirm that reading §2250 to reach only
postenactment travel does not contravene SORNA’s un
derlying purposes, let alone result in an absurdity that
would compel us to disregard the statutory text. Cf. Ar
lington Central School Dist. Bd. of Ed. v. Murphy, 548
U. S. 291, 296 (2006) (“We have stated time and again that
courts must presume that a legislature says in a statute
what it means and means in a statute what it says there.
When the statutory language is plain, the sole function of
the courts—at least where the disposition required by the
text is not absurd—is to enforce it according to its terms”
(internal quotation marks and citation omitted)).
                        *     *   *
   Having concluded that §2250 does not extend to preen
actment travel, we need not consider whether such a
construction would present difficulties under the Constitu
tion’s Ex Post Facto Clause. The judgment of the United
States Court of Appeals for the Seventh Circuit is re
versed, and the case is remanded for further proceedings
consistent with this opinion.
                                            It is so ordered.




——————
enacted statute.
                 Cite as: 560 U. S. ____ (2010)            1

                     Opinion of SCALIA, J.

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 08–1301
                         _________________


  THOMAS CARR, PETITIONER v. UNITED STATES
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

           APPEALS FOR THE SEVENTH CIRCUIT

                        [June 1, 2010]


   JUSTICE SCALIA, concurring in part and concurring in
the judgment.
   I join the Court’s opinion except for Part III–C. I do not
join that part because only the text Congress voted on, and
not unapproved statements made or comments written
during its drafting and enactment process, is an authori
tative indicator of the law. But even if those preenact
ment materials were relevant, it would be unnecessary to
address them here. The Court’s thorough discussion of
text, context, and structure, ante, at 5–17, demonstrates
that the meaning of 18 U. S. C. §2250(a) is plain. As the
Court acknowledges, ante, at 18, but does not heed, we
must not say more:
    “We have stated time and again that courts must pre
    sume that a legislature says in a statute what it
    means and means in a statute what it says there.
    When the words of a statute are unambiguous, then,
    this first canon is also the last: judicial inquiry is
    complete.” Connecticut Nat. Bank v. Germain, 503
    U. S. 249, 253–254 (1992) (citations and internal quo
    tation marks omitted).
                     Cite as: 560 U. S. ____ (2010)                    1

                          ALITO, J., dissenting

SUPREME COURT OF THE UNITED STATES
                              _________________

                              No. 08–1301
                              _________________


   THOMAS CARR, PETITIONER v. UNITED STATES
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

           APPEALS FOR THE SEVENTH CIRCUIT

                             [June 1, 2010]


   JUSTICE ALITO, with whom JUSTICE THOMAS and
JUSTICE GINSBURG join, dissenting.
   The Court’s decision misinterprets and hobbles 18
U. S. C. §2250(a), a provision of the Sex Offender Registra
tion and Notification Act (SORNA or Act) that is designed
to prevent dangerous sex offenders from evading registra
tion requirements. SORNA requires convicted sex offend
ers to register, and to keep their registrations current, in
each jurisdiction where they live, work, and go to school,
42 U. S. C. §16913, and the provision at issue here, 18
U. S. C. §2250(a), makes it a crime for a convicted sex
offender who moves in interstate commerce1 to fail to
abide by the Act’s registration requirements. The question
that we must decide is whether §2250(a) applies only to
those sex offenders who travel in interstate commerce
after SORNA became law or whether the statute also
reaches sex offenders, like petitioner, who were convicted2
——————
  1 Section 2250(a) also applies to persons with federal sex-offense con

victions, those who travel in foreign commerce, and those who enter,
leave, or reside in Indian country. For convenience, I will refer in this
opinion solely to interstate travel.
  2 The Court holds only that §2250(a)(2)(B) does not apply to a person

who moved in interstate commerce before SORNA took effect. The
Court does not address the separate question whether §2250(a) may
validly be applied to a person who was convicted of a qualifying offense
before SORNA was enacted. Congress delegated to the Attorney
General the authority to decide whether the Act’s registration require
2                    CARR v. UNITED STATES

                        ALITO, J., dissenting

and traveled before SORNA took effect but violated the
registration requirement after that date.
   The Court’s answer is that §2250(a) applies only to sex
offenders who moved from State to State after SORNA
became law. The Court reaches this conclusion for two
reasons: (1) the verb tense used in §2250(a)(2)(B); and (2)
the sequence in which the elements of the offense are
listed.
   As I will attempt to show, the Court’s textual arguments
are thoroughly unsound. And the conclusion that the
Court reaches makes no sense. To appreciate the folly of
the Court’s interpretation, consider the following two
cases.
   The first involves a situation in which, for present pur
poses, I assume that §2250(a) applies.3 A man convicted
in State A for sexual abuse is released from custody in
that State and then, after the enactment of SORNA,
moves to State B and fails to register as required by State
B law. Section 2250(a) makes this offender’s failure to
register in State B a federal crime because his interstate
movement frustrates SORNA’s registration requirements.
Because this offender is convicted and then released from
custody in State A, the State A authorities know of his
presence in their State and are thus in a position to try to
ensure that he remains registered. At the time of his
release, they can ascertain where he intends to live, and
they can make sure that he registers as required by state
law. Thereafter, they can periodically check the address
——————
ments—and thus §2250(a)’s criminal penalties—should apply to per
sons in the latter category, 42 U. S. C. §16913(d), and the Attorney
General has promulgated a regulation providing that they do, 72 Fed.
Reg. 8897 (2007) (codified at 28 CFR §72.3 (2009)). Because the Court
does not address the validity of this regulation, I proceed on the as
sumption that 18 U. S. C. §2250(a) reaches persons with pre-SORNA
sex-offense convictions.
  3 See n. 2, supra.
                 Cite as: 560 U. S. ____ (2010)            3

                     ALITO, J., dissenting

at which he is registered to confirm that he still resides
there. And even if he moves without warning to some
other address in the State, they can try to track him down.
Once this offender leaves State A, however, the authorities
in that State are severely limited in their ability to moni
tor his movements. And because the State B authorities
have no notice of his entry into their State, they are at a
great disadvantage in trying to enforce State B’s registra
tion law. Congress enacted §2250(a) in order to punish
and deter interstate movement that seriously undermines
the enforcement of sex-offender-registration laws.
   The second case is the same as the first in all respects
except that the sex offender travels from State A to State
B before SORNA’s enactment. In other words, the sex
offender is convicted and later released in State A; prior to
SORNA’s enactment, he moves to State B; and then, after
SORNA takes effects, he fails to register in State B, as
SORNA requires.
   Is there any reason why Congress might have wanted to
treat the second case any differently from the first? In
both cases, a sex offender’s interstate movement frustrates
enforcement of SORNA’s registration requirements. In
both cases, as a result of that interstate travel, the sex
offender’s new neighbors in State B are unaware of the
presence of a potentially dangerous person in their com
munity, and the State B law enforcement authorities are
hampered in their ability to protect the public. The second
case is the case now before the Court, and the Court offers
no plausible explanation why Congress might have
wanted to treat this case any differently from the first.
   If the text of §2250(a) commanded this result, we would,
of course, be obligated to heed that command. But the text
of §2250(a) dictates no such thing. On the contrary, when
properly read, it reaches both cases.
   Section 2250(a) provides in pertinent part as follows:
4                  CARR v. UNITED STATES

                      ALITO, J., dissenting

    “Whoever—
    “(1) is required to register under the Sex Offender
    Registration and Notification Act . . .
    “(2) . . . (B) travels in interstate or foreign commerce
    . . . ; and
    “(3) knowingly fails to register or update a registra
    tion 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.” (Emphasis added.)
As I read this language, neither the use of the present
tense in paragraph (2)(B) nor the sequence in which the
elements are listed provides any basis for limiting the
provision to those sex offenders who move from one State
to another after SORNA’s enactment.
                                I

                               A

   The dominant theme of petitioner’s argument is that the
use of the present tense in §2250(a)(2)(B) (“travels in
interstate . . . commerce”) indisputably means that an
offender’s interstate travel must occur after SORNA took
effect. “There is no mystery about the meaning of the
word ‘travels,’ ” petitioner tells us. Brief for Petitioner 15.
“[I]n ordinary usage it refers to present or future travel.”
Ibid. According to petitioner, our “inquiry in this case
should go no further than the plain language of
§ 2250(a)(2)(B), which applies to a person who ‘travels’ in
interstate commerce. Congress’s use of the present tense
is unambiguous, and the statutory language accordingly
should be the end of the matter.” Id., at 16–17; see also
id., at 17 (use of the present tense “travels” is “disposi
tive”); id., at 18 (“[T]he use of the present tense in the
statute should be decisive”); id., at 21 (use of the present
tense “is enough to dispose of this case”).
                 Cite as: 560 U. S. ____ (2010)           5

                     ALITO, J., dissenting

                              B
  A bad argument does not improve with repetition. And
petitioner’s argument fails because it begs the relevant
question. Petitioner belabors the obvious—that the pre
sent tense is not used to refer to events that occurred in
the past—but studiously avoids the critical question: At
what point in time does §2250(a) speak? Does it speak as
of the time when SORNA took effect? Or does it speak as
of the time when the proscribed conduct occurs? Without
knowing the point in time at which the law speaks, it is
impossible to tell what is past and what is present or
future.
  The unspoken premise of petitioner’s argument is that
§2250(a) speaks as of the time when it became law. And if
that premise is accepted, it follows that the use of the
present tense in §2250(a)(2)(B) means that the requisite
interstate travel must occur after, not before, SORNA took
effect. Petitioner’s premise, however, flies in the face of
the widely accepted modern legislative drafting convention
that a law should not be read to speak as of the date of
enactment. The United States Senate Legislative Draft
ing Manual directly addresses this point: “A legislative
provision speaks as of any date on which it is read (rather
than as of when drafted, enacted, or put into effect).”
Senate Office of the Legislative Counsel, Legislative Draft
ing Manual §103(a), p. 4 (1997) (emphasis added). The
House Manual makes the same point:
    “Your draft should be a movable feast—that is, it
    speaks as of whatever time it is being read (rather
    than as of when drafted, enacted, or put into effect).”
    House Legislative Counsel’s Manual on Drafting
    Style, HLC No. 104–1, §102(c), p. 2 (1995).
  In accordance with this convention, modern legislative
drafting manuals teach that, except in unusual circum
stances, all laws, including penal statutes, should be
6                 CARR v. UNITED STATES

                     ALITO, J., dissenting

written in the present tense. The Senate Manual, supra,
§103(a), at 4, states: “[A]lways use the present tense
unless the provision addresses only the past, the future, or
a sequence of events that requires use of a different tense.”
Similarly, the House Manual, supra, §102(c), at 2, advises:
“STAY IN THE PRESENT.–– Whenever possible, use the
present tense (rather than the past or future).” Numerous
state legislative drafting manuals and other similar hand
books hammer home this same point. See, e.g., Colorado
Legislative Drafting Manual, p. 5–15 (2009), online
at http://www.state.co.us/gov_dir/leg_dir/olls/LDM/OLLS_
Drafting_Manual.pdf (all Internet materials as visited
May 26, 2010, and available in Clerk of Court’s case
file) (“Provisions should generally be stated in the
present tense”); Hawaii Legislative Drafting Manual 21
(K. Takayama rev. 9th ed. 2007 reprint), online at
http://www.state.hi.us/lrb/rpts96/dftman.pdf (“Use the
present tense and indicative mood”); Legislative Research
Comm’n, Bill Drafting Manual for the Kentucky General
Assembly, §304, p. 19 (14th rev. ed. 2004) (“Use the pre
sent tense and the indacative mood”); Maine Legislative
Drafting Manual 78 (rev. ed. 2009) (“Laws are meant to be
of continuing application and should be written in the
present tense”); Massachusetts General Courts, Legisla
tive Research and Drafting Manual 6 (5th ed. 2010) (“Use
the present tense and the indicative mood”); New Mexico
Legislative     Counsel     Service,    Legislative    Draft-
ing Manual 105 (2004 update) (“Statutes are written in
the present tense, not the future tense”); Texas Leg
islative Council Drafting Manual §7.35 (2008) (“Use
present tense whenever possible”); West Virginia Leg-
islature Bill Drafting Manual 22 (rev. 2006), online
at http://www.legis.state.wv.us/joint/Bill_Drafting/Drafting_
Manual.pdf (“Avoid future tense (will be paid) and future
perfect tense (will have been paid). Use present
tense (is paid)”); see also Ohio Legislative Service Com
                      Cite as: 560 U. S. ____ (2010)                      7

                           ALITO, J., dissenting

mission, Rule Drafting Manual 47 (4th ed. 2006),
http://www.lsc.state.oh.us/rules/rdm06_06.pdf (“Use pre
sent tense. The majority of rules have a continuing effect
in that they apply over time. They speak at the time of
reading, not merely at the time of their adoption. The
present tense therefore includes the future tense”).
   Once it is recognized that §2250(a) should not be read as
speaking as of the date when SORNA went into effect,
petitioner’s argument about the use of the present tense
collapses. In accordance with current drafting conven
tions, §2250(a) speaks, not as of the time when the law
went into effect, but as of the time when the first act
necessary for conviction is committed. In the case of
§2250(a), that occurs when an individual is convicted of a
qualifying sex offense, for it is that act that triggers the
requirement to register under SORNA.4 For present
purposes, we must proceed on the assumption that this
event may have occurred before SORNA was enacted.
Viewed as of the time when such a pre-SORNA conviction
takes place, every subsequent act, including movement
from State to State, occurs in the future and is thus prop
erly described using the present tense. Accordingly,
§2250(a)(2)(B)’s use of the present tense (“travels”) sup
ports the application of the statute to a sex offender, like
petitioner, who moved from State to State after conviction
but before SORNA went into effect.5
——————
  4 Under  42 U. S. C. §16913, a “sex offender” is required to register,
and the term “sex offender” is defined as a person who was convicted of
a “sex offense.” §16911(1). The Court relies on the artificial argument
that the first act necessary for conviction under 18 U. S. C. §2250(a) is
the failure to register, ante, at 6–7, and n. 4, but in real-world terms the
first necessary act is plainly the commission of a qualifying offense.
   5 Contrary to the Court’s interpretation, see ante, at 8–9, Gwaltney of

Smithfield, Ltd. v. Chesapeake Bay Foundation, Inc., 484 U. S. 49
(1987), does not support petitioner’s argument. Gwaltney involved a
civil action brought under §505 of the Clean Water Act, 33 U. S. C.
§1365(a), which authorizes suit against any person “alleged to be in
8                     CARR v. UNITED STATES


                         ALITO, J., dissenting 


                              C

  Petitioner’s present-tense argument is particularly
perverse in light of the context in which §2250(a) was
adopted. When SORNA was enacted, Congress elected not
to decide for itself whether the Act’s registration require
ments—and thus §2250(a)’s criminal penalties—would
apply to persons who had been convicted of qualifying sex
offenses before SORNA took effect. Instead, Congress
delegated to the Attorney General the authority to decide
that question. See §113(d), 120 Stat. 594, 42 U. S. C.
§16913(d) (“The Attorney General shall have the authority
to specify the applicability of the requirements of [Title I
of SORNA] to sex offenders convicted before the enact
ment of this Act”).6 Pursuant to this delegation, the At
——————
violation” of a National Pollutant Discharge Elimination System
permit. In Gwaltney, the permit holder had violated its permit between
1981 and 1984, but the permit holder claimed that it had ceased all
violations by the time the suit was filed. 484 U. S., at 53–55. This
Court held that the phrase “alleged to be in violation” showed that the
provision was meant to apply only where an ongoing violation is al
leged. Id., at 59.
  The provision at issue in Gwaltney differs from §2250(a) in that it
specifies the relevant temporal point of reference, namely, the point in
time when the allegation of an ongoing violation is made. Section
2250(a) contains no similar specification. Moreover, the Gwaltney
Court did not read the provision at issue there as speaking at the time
when the provision was enacted. As noted above, however, the silent
premise of petitioner’s argument is that §2250(a) must be read as
speaking as of the time of SORNA’s enactment.
  6 To be sure, at least two Courts of Appeals have held that SORNA’s

registration requirements apply by the Act’s own terms to those indi
viduals with sex-offense convictions that predate SORNA’s enactment.
See United States v. Hinckley, 550 F. 3d 926, 929–935 (CA10 2008);
United States v. May, 535 F. 3d 912, 918–919 (CA8 2008). Other
Courts of Appeals, however, have disagreed, reasoning that SORNA’s
explicit grant of authority to the Attorney General to determine the
Act’s applicability to offenders with pre-SORNA convictions implies
that the Act would not apply to those sex offenders absent the Attorney
General’s regulation. See, e.g., United States v. Cain, 583 F. 3d 408,
                     Cite as: 560 U. S. ____ (2010)                   9

                         ALITO, J., dissenting

torney General in 2007 issued an interim rule providing
that SORNA applies to pre-enactment convictions. 72
Fed. Reg. 8897 (codified at 28 CFR §72.3).7
   Petitioner contends that, if Congress had wanted to
make §2250(a) applicable to sex offenders who traveled in
interstate commerce before SORNA took effect, Congress
could have referred in §2250(a)(2)(B) to a person who
“traveled,” “has traveled,” or, at the time of the statute’s
enactment, “had traveled” in interstate commerce. Brief
for Petitioner 19 (internal quotation marks omitted). Any
such phrasing, however, would have strongly suggested
that §2250(a) reaches persons with pre-SORNA sex
offense convictions—the very question that Congress chose
not to decide but instead to leave for the Attorney General.
   A brief explanation is needed to make clear why word
ing §2250(a)(2)(B) in the past tense (or the present perfect
or past perfect tense) would have had such an effect. The
Court and I agree that §2250(a) applies only to persons
who travel in interstate commerce after they are convicted
of a qualifying sex offense. See ante, at 6; infra, at 11–12.
Therefore, if §2250(a) had been phrased in the past tense
(or the present perfect or past perfect tense), it would
——————
414–415, 419 (CA6 2009); United States v. Hatcher, 560 F. 3d 222, 226–
229 (CA4 2009); United States v. Dixon, 551 F. 3d 578, 585 (CA7 2008)
(case below); United States v. Madera, 528 F. 3d 852, 856–859 (CA11
2008). Those Courts of Appeals in the latter group, in my view, have
the better of the argument. Section 113(d) of SORNA delegates to the
Attorney General the “authority to specify the applicability of the
requirements of [Title I of SORNA] to sex offenders convicted before the
enactment of [the] Act.” 120 Stat. 594, 42 U. S. C. §16913(d). The clear
negative implication of that delegation is that, without such a determi
nation by the Attorney General, the Act would not apply to those with
pre-SORNA sex-offense convictions.
  7 Although not controlling, it is worth noting that one of the two ex

amples the Attorney General included in his February 2007 rule
contemplated that pre-SORNA travel would be sufficient to satisfy
§2250(a)(2)(B)’s interstate-travel requirement. See 28 CFR §72.3
(Example 2).
10                   CARR v. UNITED STATES

                         ALITO, J., dissenting

seem necessarily to follow that the provision reaches pre-
SORNA convictions. By using the present tense, Congress
remained neutral on the question whether the Act reaches
those with pre-SORNA sex-offense convictions and left
that question open for the Attorney General.
   The conclusion that §2250(a)(2)(B) embraces pre-
SORNA travel is reinforced by the presence of quite a few
other SORNA provisions that plainly use the present
tense to refer to events that, as a result of the Attorney
General’s regulation, may have occurred before SORNA
took effect. For example, an individual may qualify as a
“tier II sex offender” under the Act if, among other things,
his sex offense “involves . . . (i) use of a minor in sexual
performance; (ii) solicitation of a minor to practice prosti
tution; or (iii) production or distribution of child pornogra
phy.” 42 U. S. C. §16911(3)(B) (emphasis added); see also
§16911(4)(B) (offense “involves kidnapping a minor” (em
phasis added)); §16911(7) (offense “involves” certain speci
fied conduct). Similarly, a sex offender can qualify as a
“tier II sex offender” if his sex offense “occurs after the
offender becomes a tier I sex offender.” §16911(3)(C) (em
phasis added); see also §16911(4)(C) (offense “occurs after
the offender becomes a tier II sex offender” (emphasis
added)). A juvenile adjudication, moreover, may qualify as
a conviction for purposes of the Act only if, among other
things, the “offender is 14 years of age or older at the time
of the offense.” §16911(8) (emphasis added).8
——————
  8 That many of these provisions rely on §16911(1)’s definition of the

term “sex offender” changes nothing. See ante, at 10, n. 6. Had the
Attorney General not exercised his discretion to make SORNA’s regis
tration requirements applicable to those with pre-SORNA sex-offense
convictions, all of these provisions would have applied to only pos
tenactment conduct—notwithstanding §16911(1)’s reference to “an
individual who was convicted of a sex offense.” (Emphasis added.) But
now that the Attorney General has so exercised his discretion, all of
these present-tense-phrased provisions necessarily must be interpreted
as reaching pre-enactment conduct. The same conclusion should follow
                    Cite as: 560 U. S. ____ (2010)                  11

                         ALITO, J., dissenting

   Congress cast all of these provisions in the present
tense, but now that the Attorney General has made
SORNA applicable to individuals with pre-SORNA sex
offense convictions, all of these provisions must necessar
ily be interpreted as embracing pre-enactment conduct.
                               II
   The Court’s second reason for holding that 18 U. S. C.
§2250(a) reaches only post-SORNA travel is based on the
sequence in which the elements of §2250(a) are listed. The
Court concludes (and I agree) that the first listed element
(subsection (a)(1) (“is required to register under the Sex
Offender Registration and Notification Act”)) cannot have
been violated until the Act took effect. The Court then
reasons that the third listed element (subsection (a)(2)(B)
(“travels in interstate . . . commerce”)) must be violated
after the first. See ante, at 6. The Court explains: “Per
sons convicted of sex offenses under state law who fail to
register in their State of conviction would otherwise be
subject to federal prosecution under §2250 even if they
had not left the State after being convicted—an illogical
result given the absence of any obvious federal interest in
punishing such state offenders.” Ibid. In other words, the
Court reasons that it would be illogical to interpret the
statute as reaching a person who first moves from State A
——————
with respect to 18 U. S. C. §2250(a)(2)(B).
  Additionally, I do not suggest that the “default” rule is that provi
sions written in the present tense apply to past conduct. To the con
trary, I had thought it an uncontroversial proposition of statutory
interpretation that statutes must be interpreted in context. See, e.g.,
United States Nat. Bank of Ore. v. Independent Ins. Agents of America,
Inc., 508 U. S. 439, 455 (1993); see also 1 U. S. C. § 1. And when
§2250(a) is read with an eye to the context in which SORNA was
enacted, it becomes quite clear that §2250(a)(2)(B) should be inter
preted as reaching pre-enactment travel. Giving effect to those contex
tual indicators, moreover, does not offend the presumption against
retroactivity or the Ex Post Facto Clause. See n. 10, infra.
12                CARR v. UNITED STATES

                     ALITO, J., dissenting

to State B, then commits and is convicted of a qualifying
sex offense in State B, and subsequently, upon release
from custody in State B, fails to register as required under
the law of that State.
   I agree with the Court that there is a good argument
that §2250(a) should not be read to apply to such a case,
where there is little if any connection between the of
fender’s prior interstate movement and his subsequent
failure to register. In the two hypothetical cases discussed
at the beginning of this opinion, the offender’s interstate
movement seriously frustrated the ability of the law en
forcement authorities in his new State (State B) to enforce
its registration requirements. By contrast, where an
offender’s interstate movement predates his sex offense
and conviction, his interstate movement has little if any
effect on the ability of the law enforcement authorities in
State B to enforce that State’s laws. When a sex offender
is released from custody in State B, the ability of the State
B authorities to enforce that State’s registration laws
would appear to be the same regardless of whether that
offender had lived his entire life in that State or had
moved to the State prior to committing the offense for
which he was convicted. Accordingly, it can be argued
that Congress cannot have meant to reach this situation.
As the Seventh Circuit put it, “[s]ince the statutory aim is
to prevent a convicted sex offender from circumventing
registration by leaving the state in which he is registered,
it can be argued that the travel must postdate the convic
tion.” United States v. Dixon, 551 F. 3d 578, 582 (2008).
It can also be argued that a broader construction would
mean that Congress exceeded its authority under the
Commerce Clause. See Brief for National Association of
Criminal Defense Lawyers as Amicus Curiae 16–17.
   What the Court’s argument shows, however, is not that
the interstate travel required by §2250(a) must come after
SORNA’s enactment. Rather, what the Court’s argument
                 Cite as: 560 U. S. ____ (2010)          13

                     ALITO, J., dissenting

suggests is that the interstate travel must come after the
sex-offense conviction. And because, under the regulation
promulgated by the Attorney General, §2250(a) reaches
pre-SORNA convictions, this argument does not support
the Court’s conclusion that the interstate travel needed
under §2250(a) must have occurred after SORNA was
enacted.
                             III
   When an interpretation of a statutory text leads to a
result that makes no sense, a court should at a minimum
go back and verify that the textual analysis is correct.
Here, not only are the Court’s textual arguments unsound
for the reasons explained above, but the indefensible
results produced by the Court’s interpretation should have
led the Court to doublecheck its textual analysis.
   SORNA was a response to a dangerous gap in the then
existing sex-offender-registration laws. 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. In response, Congress and
state legislatures passed laws requiring the registration of
sex offenders. See Smith v. Doe, 538 U. S. 84, 89–90
(2003); Jacob Wetterling Crimes Against Children and
Sexually Violent Offender Registration Act, Tit. 17, 108
Stat. 2038; Megan’s Law, 110 Stat. 1345. Despite those
efforts, by 2006 an estimated 100,000 convicted sex of
fenders—nearly one-fifth of the Nation’s total sex-offender
population—remained unregistered. H. R. Rep. No. 109–
218, pt. 1, p. 26 (2005). The principal problem, a House
Report determined, was that sex offenders commonly
moved from one State to another and then failed to regis
ter in their new State of residence. Ibid. In other words,
interstate travel was dangerously undermining the effec
tiveness of state sex-offender-registration laws.
14                     CARR v. UNITED STATES

                           ALITO, J., dissenting

   Interpreting §2250(a)(2)(B) to reach only postenactment
travel severely impairs §2250(a)’s effectiveness. As inter
preted by the Court, §2250(a) applies to a pre-SORNA sex
offender only if that offender traveled in interstate com
merce at some point after SORNA’s enactment. As the
examples discussed at the beginning of this opinion illus
trate, however, there is no apparent reason why Congress
would have wanted to impose such a requirement. To the
contrary, under the Court’s interpretation, the many sex
offenders who had managed to avoid pre-existing registra
tion regimes, mainly by moving from one State to another
before SORNA’s enactment, are placed beyond the reach of
the federal criminal laws. It surely better serves the
enforcement of SORNA’s registration requirements to
apply §2250(a) to all pre-SORNA sex offenders, regardless
of whether their interstate travel occurred before or after
the statute’s enactment.
   The Court provides only a weak defense of the result its
analysis produces. The Court suggests that enhanced
information collection and sharing and state enforcement
of registration laws were the sole weapons that Congress
chose to wield in order to deal with those convicted sex
offenders whose whereabouts were unknown when
SORNA was passed. See ante, at 14–16. I see no basis for
this conclusion. There can be no dispute that the enact
ment of §2250(a) shows that Congress did not think these
measures were sufficient to deal with persons who have
qualifying sex-offense convictions and who move from
State to State after SORNA’s enactment. And in light of
that congressional judgment, is there any plausible reason
to think that Congress concluded that these same meas
ures would be adequate for those with qualifying sex
offense convictions who had already disappeared at the
time of SORNA’s enactment?9 The Court has no answer,
——————
 9 Contrary   to the Court’s suggestion, see ante, at 15, n. 9, it is no an
                      Cite as: 560 U. S. ____ (2010)                    15

                          ALITO, J., dissenting

and I submit that there is none.10
                            IV
  For these reasons, I would affirm the decision of the
Seventh Circuit, and I therefore respectfully dissent.




——————
swer to point to Congress’ decision to delegate to the Attorney General
the responsibility of deciding whether §2250(a) should reach persons
with pre-SORNA sex-offense convictions. Of course, that delegation
created the possibility that the Attorney General would decide that
§2250(a) should not apply to such offenders, and if he had so decided it
would likely follow that post-SORNA interstate travel would also be
required. (This is the case because, as previously explained, there is a
strong argument that §2250(a) requires interstate travel that comes
after a qualifying conviction.)
  Now that the Attorney General has decided that §2250(a) reaches
persons with pre-SORNA sex offense convictions, however, the relevant
question is this: Is there any reason why Congress might have wanted
to draw a distinction between (1) persons with pre-SORNA convictions
and pre-SORNA travel and (2) persons with pre-SORNA convictions
and post-SORNA travel? And to this question, the Court offers no
plausible answer.
  10 Petitioner makes the additional argument that interpreting

§2250(a)(2)(B) to reach pre-enactment travel renders the statute an
unlawful ex post facto law. See U. S. Const., Art. I, §9, cl. 3. Petitioner
remained unregistered in Indiana five months after the promulgation
of the regulation making SORNA applicable to persons with pre-
SORNA sex-offense convictions. For essentially the reasons explained
by the Court of Appeals, see United States v. Dixon, 551 F. 3d, at 585–
587, I would reject petitioner’s ex post facto argument.
