PUBLISHED

UNITED STATES COURT OF APPEALS
                 FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                              No. 03-4506
MICHAEL A. THOMAS,
             Defendant-Appellant.
                                       
           Appeal from the United States District Court
         for the Eastern District of Virginia, at Richmond.
                  Robert E. Payne, District Judge.
                           (CR-03-113)

                      Argued: February 26, 2004

                        Decided: May 4, 2004

          Before WILKINS, Chief Judge, and MOTZ and
                   TRAXLER, Circuit Judges.



Vacated and remanded by published opinion. Chief Judge Wilkins
wrote the opinion, in which Judge Motz and Judge Traxler joined.


                             COUNSEL

ARGUED: Christina Kearney Saba, Glen Allen, Virginia, for Appel-
lant. Sara Elizabeth Flannery, Assistant United States Attorney, Rich-
mond, Virginia, for Appellee. ON BRIEF: Paul J. McNulty, United
States Attorney, Richmond, Virginia, for Appellee.
2                     UNITED STATES v. THOMAS
                             OPINION

WILKINS, Chief Judge:

   Michael Anthony Thomas appeals his conviction for fourth-offense
driving while intoxicated (DWI) on a federal reservation in Virginia.
See 18 U.S.C.A. § 13 (West 2000) (adopting state law for areas within
federal jurisdiction); Va. Code Ann. §§ 18.2-266, 18.2-270(C)
(Michie 1996 & LexisNexis Supp. 2003). The indictment alleged that
Thomas had three prior DWI convictions in Maryland. We vacate
Thomas’ conviction and sentence and remand for further proceedings.

                                  I.

  Thomas was stopped by a federal officer while driving early on the
morning of January 13, 2001, at Dahlgren Naval Surface Warfare
Center. He subsequently failed field sobriety and breathalyzer tests.
As a result of this incident and the fact that he had three previous
Maryland DWI convictions—two in 1997 and one in 1999—Thomas
was indicted for fourth-offense DWI.

   Thomas subsequently moved to dismiss the indictment, arguing
that the Maryland statute under which he had been previously con-
victed was not sufficiently similar to Virginia Code § 18.2-266 for the
Maryland convictions to warrant a fourth-offense conviction. After
hearing testimony from Maryland prosecutor Matthew Stiglitz regard-
ing how Maryland DWI laws are applied, the district court denied
Thomas’ motion.

   Thomas then pled guilty to the indictment. As part of the plea
agreement, he reserved the right to appeal the denial of his motion to
dismiss. The district court later accepted Thomas’ guilty plea and
entered a judgment of guilt on the charge. The court imposed a sen-
tence of 36 months imprisonment.

                                  II.

 Thomas argues that the district court erred in concluding that the
Maryland statute under which he had been previously convicted is
                       UNITED STATES v. THOMAS                          3
substantially similar to Virginia Code § 18.2-266. Thomas therefore
asserts that the district court erred in denying his motion to dismiss
the indictment.

                                   A.

   Initially, we note some uncertainty regarding the procedural pos-
ture of this claim. To warrant dismissal of the indictment, Thomas
would need to demonstrate that the allegations therein, even if true,
would not state an offense. See United States v. Hooker, 

, 1227-28 (4th Cir. 1988) (en banc). Despite Thomas’ claim that
he is appealing the denial of his motion to dismiss the indictment, his
argument to us concerns not the sufficiency of the indictment allega-
tions, but rather, the sufficiency of the record to support a finding that
Thomas was guilty of fourth-offense DWI.1 Specifically, he argues
that there is no basis in the record for concluding that he has three
predicate offenses since the Maryland statute under which he was
convicted is not substantially similar to the Virginia statute at issue
here. In light of the nature of Thomas’ argument, we are inclined to
treat it as a challenge to the adequacy of the factual basis supporting
his plea even though he has not explicitly framed it as such. See
United States v. Klecker, 

, 72-73 (4th Cir. 2003) (treating
argument as challenge to factual basis for guilty plea under similar
circumstances), petition for cert. filed (U.S. Jan. 22, 2004) (No. 03-
9238). And, we conclude that this challenge has merit.

   Federal Rule of Criminal Procedure 11(b)(3) provides that
"[b]efore entering judgment on a guilty plea, the court must determine
that there is a factual basis for the plea." This rule "ensures that the
court make clear exactly what a defendant admits to, and whether
those admissions are factually sufficient to constitute the alleged
crime." United States v. DeFusco, 

, 120 (4th Cir. 1991).
  1
    We conclude that the allegations in the indictment here adequately
state the offense of fourth-offense DWI. See Russell v. United States, 

, 763-64 (1962) (explaining that the purposes of an indictment
are (1) to notify a defendant of the charge against him so that he may
prepare to defend himself and (2) to enable him to plead a double jeop-
ardy bar, if applicable). Thus, the district court did not err in denying
Thomas’ motion to dismiss.
4                      UNITED STATES v. THOMAS
The factual basis need not be established during the plea colloquy;
rather, it may be established "from anything that appears on the
record." 

a finding of a factual basis for a guilty plea
for abuse of discretion. See United States v. Mitchell, 

,
652 (4th Cir. 1997).

                                  B.

   To determine whether the Maryland convictions could serve as
predicates for Thomas’ fourth-offense conviction, we must consider
the applicable substantive law. Thomas was charged with violating
the Assimilative Crimes Act, see 18 U.S.C.A. § 13, which assimilated
Virginia’s DWI statutes, see Va. Code Ann. §§ 18.2-266, 18.2-270(C).2
The existence of the predicate convictions constitutes an element of
the offense of fourth-offense DWI. See McBride v. Commonwealth,

, 127 (Va. Ct. App. 1997). For previous convictions
to constitute predicate offenses under § 18.2-270(C), the statutes on
which the previous convictions are based must be substantially simi-
lar to Virginia Code § 18.2-266. See Commonwealth v. Ayers, 

, 581 (Va. Ct. App. 1993). That "does not mean that the
other state’s law must substantially conform in every respect to Code
§ 18.2-266. Only that prohibition of the other state’s law under which
the person was convicted must substantially conform." 

internal quotation marks omitted). A statute is substantially similar
if any actions violating the statute necessarily would violate the Vir-
ginia statute as well. See Turner v. Commonwealth, 

,
472 (Va. Ct. App. 2002). The burden is on the Government to prove
that a prior conviction was under a conforming statute. See Shinault
v. Commonwealth, 

, 654 (Va. 1984).

   We therefore must compare the relevant statutes. The parties agree
that the relevant Virginia statute is Virginia Code § 18.2-266, which
prohibits
    2
    The Assimilative Crimes Act provides that absent a governing federal
statute, one who commits a state crime on a federal enclave "shall be
guilty of a like offense and subject to a like punishment." 18 U.S.C.A.
§ 13(a).
                       UNITED STATES v. THOMAS                        5
    any person [from] driv[ing] or operat[ing] any motor vehicle
    . . . (i) while such person has a blood alcohol concentration
    of 0.08 percent or more by weight by volume or 0.08 grams
    or more per 210 liters of breath as indicated by a chemical
    test administered as provided in this article [or] (ii) while
    such person is under the influence of alcohol. . . .

Importantly, under the Virginia statutory scheme, test results reveal-
ing a threshold blood alcohol concentration do not conclusively estab-
lish either that the threshold concentration was present at the time of
driving (for purposes of § 18.2-266(i)), or that the defendant was in
fact under the influence of alcohol at the time of driving (for purposes
of § 18.2-266(ii)). Rather, such results create only a rebuttable pre-
sumption of those facts. See Va. Code Ann. § 18.2-269(3) (Michie
1996); Davis v. Commonwealth, 

, 15 (Va. Ct. App.
1989).

   Although the question of exactly what prohibition was the source
of Thomas’ Maryland convictions is the subject of significant debate,
the parties agree that Thomas was convicted under some portion of
Maryland Transportation Code § 21-902(a) (LexisNexis Supp. 2003),
which provides:

       (a) Driving while under the influence of alcohol or under
    the influence of alcohol per se. — (1) A person may not
    drive or attempt to drive any vehicle while under the influ-
    ence of alcohol.

         (2) A person may not drive or attempt to drive any
    vehicle while the person is under the influence of alcohol
    per se.

Maryland law defines "under the influence of alcohol per se" as "hav-
ing an alcohol concentration at the time of testing of 0.08 or more as
measured by grams of alcohol per 100 milliliters of blood or grams
of alcohol per 210 liters of breath." Md. Code Ann., Transp. II § 11-
127.1(a) (2002).

  The parties appear to agree that § 21-902(a)(1) conforms to § 18.2-
6                       UNITED STATES v. THOMAS
266(ii). Section 21-902(a)(2) is a different story, however. One could
violate § 21-902(a)(2), which prohibits having too high a blood alco-
hol level "at the time of testing," without violating the Virginia stat-
ute. That is because although a blood alcohol test result can
conclusively prove a violation of § 21-902(a)(2), under the Virginia
statute it can only create a presumption of guilt that may be rebutted
by a showing that the defendant did not have an illegally high blood
alcohol level when he was driving. See 

.
Thus, because § 21-902(a)(2) does not conform to the Virginia stat-
ute, no conviction based on a violation of § 21-902(a)(2) can serve as
a predicate offense.3 See 

reason, the critical issue in this appeal is whether the
record establishes that Thomas was convicted under (a)(1) or, alterna-
tively, leaves open the possibility that he was prosecuted on an (a)(2)
theory. We conclude that the record does not indicate which theory
was employed. With respect to each of Thomas’ prior convictions, the
offense charged in the Maryland charging document was a violation
of § 21-902(a). Stiglitz testified that he knew that Thomas "pled
guilty to [(a)] because that’s the only plea we ever take. There’s never
a distinction either at trial in the verdict or in the plea process of a ref-
erence to the subsection, [(a)(1)] or [(a)(2)]. It’s generally to the—it’s
to the general section . . . (a)." J.A. 49-50. Stiglitz further stated that
Maryland courts had interpreted (a)(2) not as creating a separate
offense, but rather as "simply creating a new mode of proof" of the
general section (a) offense. 

Indeed, the Maryland Court of
Special Appeals had accepted this conclusion. See Meanor v. State,

, 1129 (Md. Ct. Spec. App. 2000).

   We recognize that this conclusion was subsequently rejected by the
Maryland Court of Appeals on appeal in the same case. See Meanor
v. State, 

, 398-402 (Md. 2001). In that decision, the
Court of Appeals held that (a)(1) and (a)(2) create two separate
    3
    The Government contends that this argument is at odds with Com-
monwealth v. Lowe, 

, 640 (Va. Ct. App. 2000), and Graf-
ton v. Commonwealth, 50 Va. Cir. 530 (1999), both of which declare that
the Maryland and Virginia DWI statutes are substantially similar. How-
ever, because neither of these decisions discusses the particular dissimi-
larity at issue here, we choose not to adopt their broad conclusions.
                       UNITED STATES v. THOMAS                        7
offenses and that a defendant may not be convicted under (a)(2)
unless an intoxication per se theory is specifically alleged in the
charging document. See 

   It could be argued that under Meanor, the Maryland charging docu-
ments, which cite § 21-902(a) generally, would have been insufficient
to support (a)(2) convictions, and thus the convictions must have been
under (a)(1). We do not accept that analysis, however. In order to
determine what offenses Thomas was convicted of in 1997 and 1999,
we must look at the charging documents and records of conviction in
light of the then-prevailing practices; we may not apply Meanor retro-
actively to resolve ambiguities created by the very prosecutorial prac-
tices that Meanor stopped. Stated another way, even if it would have
been error in 1997 and 1999 for the Maryland courts to adjudge
Thomas guilty under § 21-902(a) generally, that does not negate the
fact that Thomas was in fact charged under § 21-902(a) generally, and
the record does not indicate whether the applicable theory of prosecu-
tion implicated (a)(1) or (a)(2).

   Since Thomas’ charging documents and records of conviction refer
to § 21-902(a) generally, the record does not give rise to a reasonable
inference that the statutes on which Thomas’ prior convictions were
based substantially conform to § 18.2-266. On the contrary, the record
leaves open the possibility that Thomas was convicted under § 21-
902(a)(2), which is not substantially similar to § 18.2-266 for the rea-
son already discussed. We therefore conclude that the district court
abused its discretion in accepting Thomas’ guilty plea to fourth-
offense DWI.

                                  III.

   For the foregoing reasons, we vacate Thomas’ conviction and sen-
tence for fourth-offense DWI and remand for further proceedings
consistent with this opinion.

                                         VACATED AND REMANDED