                            PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                               No. 02-4961
RICHARD LESTER KLECKER,
              Defendant-Appellant.
                                       
           Appeal from the United States District Court
          for the Eastern District of Virginia, at Norfolk.
              Henry Coke Morgan, Jr., District Judge.
                            (CR-02-68)

                      Argued: September 26, 2003

                      Decided: October 27, 2003

        Before WILKINS, Chief Judge, and HAMILTON,
                   Senior Circuit Judge.*



Affirmed by published opinion. Chief Judge Wilkins wrote the opin-
ion, in which Senior Judge Hamilton joined.


                             COUNSEL

ARGUED: David Wayne Bouchard, Chesapeake, Virginia, for
Appellant. Laura P. Tayman, Assistant United States Attorney,
UNITED STATES ATTORNEY’S OFFICE, Norfolk, Virginia, for

  *This appeal is decided by Chief Judge Wilkins and Senior Judge
Hamilton as a quorum.
2                     UNITED STATES v. KLECKER
Appellee. ON BRIEF: Paul J. McNulty, United States Attorney,
UNITED STATES ATTORNEY’S OFFICE, Norfolk, Virginia, for
Appellee.


                              OPINION

WILKINS, Chief Judge:

   Richard Lester Klecker was convicted of two offenses involving
distribution of 5-methoxy-N,N-diisopropyltryptamine (commonly cal-
led "Foxy"). Although Foxy was not listed as a controlled substance
when the offenses occurred, the Government alleged that Foxy was
an analogue of diethyltryptamine (DET), a schedule I controlled sub-
stance, and that Klecker’s activities were therefore unlawful under the
Controlled Substance Analogue Enforcement Act of 1986 ("Analogue
Act"), see 21 U.S.C.A. §§ 802(32), 813 (West 1999 & Supp. 2003).1
Klecker maintains that the Analogue Act is unconstitutionally vague
and that, in any event, Foxy is not an analogue of DET. We affirm.

                                   I.

   In March 2002, Klecker was indicted for multiple drug trafficking
offenses, including conspiracy to distribute Foxy and other substances,2
see 21 U.S.C.A. § 846 (West 1999), and distribution of Foxy to a per-
son under 21 years of age, see 21 U.S.C.A. § 859 (West 1999).
Klecker moved to dismiss the indictment, asserting that the Analogue
Act is unconstitutionally vague on its face and as applied to Foxy.
After hearing two days of testimony, the district court held that the
Analogue Act is not vague. The court further found that Foxy is in
    1
     After Klecker was indicted, the Drug Enforcement Administration
used its emergency powers to add Foxy to schedule I for one year. See
Schedules of Controlled Substances, 21 C.F.R. § 1308.11(g)(7) (2003),
WL 21 CFR s 1308.11.
   2
     One of the substances listed in the indictment was alpha-
methyltryptamine (AMT), which was alleged to be an analogue of alpha-
ethyltryptamine. Klecker has not raised any claims relating to AMT in
this appeal.
                       UNITED STATES v. KLECKER                        3
fact an analogue of DET. Following this ruling, Klecker pled guilty
to conspiracy and distribution to a person under age 21. Klecker
reserved the right to appeal both the denial of his motion to dismiss
and the finding that Foxy is a controlled substance analogue.

                                   II.

   Congress enacted the Analogue Act to prevent underground chem-
ists from altering illegal drugs in order to create new drugs that are
similar to their precursors in effect but are not subject to the restric-
tions imposed on controlled substances. See United States v. Hodge,
321 F.3d 429, 432 (3d Cir. 2003). The Act defines a "controlled sub-
stance analogue" as

    a substance—

       (i) the chemical structure of which is substantially simi-
    lar to the chemical structure of a controlled substance in
    schedule I or II;

       (ii) which has a stimulant, depressant, or hallucinogenic
    effect on the central nervous system that is substantially
    similar to or greater than the stimulant, depressant, or hallu-
    cinogenic effect on the central nervous system of a con-
    trolled substance in schedule I or II; or

      (iii) with respect to a particular person, which such per-
    son represents or intends to have a stimulant, depressant, or
    hallucinogenic effect on the central nervous system that is
    substantially similar to or greater than the stimulant, depres-
    sant, or hallucinogenic effect on the central nervous system
    of a controlled substance in schedule I or II.

21 U.S.C.A. § 802(32)(A). The Act further provides that "[a] con-
trolled substance analogue shall, to the extent intended for human
consumption, be treated, for the purposes of any Federal law as a con-
trolled substance in schedule I." 21 U.S.C.A. § 813.

   Klecker contends that the definition of a controlled substance ana-
logue is so indeterminate that it renders the Analogue Act void for
4                     UNITED STATES v. KLECKER
vagueness. He further claims that Foxy is not sufficiently similar to
DET to qualify as an analogue.

                                  A.

   We turn first to Klecker’s vagueness claim. Klecker asserts that the
Analogue Act is impermissibly vague both on its face and as applied
to Foxy. Facial vagueness challenges to criminal statutes are allowed
only when the statute implicates First Amendment rights. See United
States v. Sun, 278 F.3d 302, 309 (4th Cir. 2002). Accordingly, we will
only consider the "as applied" challenge.

   "The void-for-vagueness doctrine requires that penal statutes define
crimes so that ordinary people can understand the conduct prohibited
and so that arbitrary and discriminatory enforcement is not encour-
aged." United States v. McLamb, 985 F.2d 1284, 1291 (4th Cir.
1993). In evaluating whether a statute is vague, a court must consider
both whether it provides notice to the public and whether it ade-
quately curtails arbitrary enforcement. See Kolender v. Lawson, 461
U.S. 352, 357-58 (1983) (stating, in the context of a facial challenge,
that preventing arbitrary enforcement is "the more important aspect of
the vagueness doctrine").

   The requirement of preventing arbitrary enforcement is easily satis-
fied here. In order to show an Analogue Act violation, the Govern-
ment must prove (1) substantial chemical similarity between the
alleged analogue and a controlled substance, see 21 U.S.C.A.
§ 802(32)(A)(i); (2) actual, intended, or claimed physiological simi-
larity (in other words, that the alleged analogue has effects similar to
those of a controlled substance or that the defendant intended or rep-
resented that the substance would have such effects), see id.
§ 802(32)(A)(ii), (iii); and (3) intent that the substance be consumed
by humans, see id. § 813. Cf. Hodge, 321 F.3d at 436-39 (interpreting
§ 802(32)(A)). The intent requirement alone tends to defeat any
vagueness challenge based on the potential for arbitrary enforcement.
See United States v. Carlson, 87 F.3d 440, 444 (11th Cir. 1996).

   The question of whether the statute provides adequate notice is
closer. Klecker claims that the phrases "chemical structure" and "sub-
stantially similar" do not provide adequate guidance to a person trying
                       UNITED STATES v. KLECKER                         5
to determine whether one molecule resembles another closely enough
to qualify as an analogue. Indeed, the testimony presented below
illustrates that even experts can disagree about whether two molecules
have chemical structures that are substantially similar; the Govern-
ment’s experts relied primarily on their structural diagrams of Foxy
and DET and concluded that they were similar, while Klecker’s
expert compared several different properties of the two molecules
(including weight, shape, and the relative amounts of different types
of atoms) and found significant differences.

   Notwithstanding this indeterminacy in § 802(32)(A), other courts
of appeals have unanimously rejected vagueness challenges to Ana-
logue Act prosecutions.3 While these cases are not directly on point
because they concerned substances other than Foxy and DET, they
are nevertheless instructive to the extent that they identify factors per-
tinent to our analysis. In particular, United States v. McKinney teaches
that it is useful to compare chemical diagrams of the controlled sub-
stance and the alleged analogue. See United States v. McKinney, 79
F.3d 105, 108 (8th Cir. 1996), vacated on other grounds, 520 U.S.
1226 (1997).

   The diagrams admitted into evidence during the hearing on Kleck-
er’s motion demonstrate considerable similarities between Foxy and
DET, particularly when compared to other substances that might be
consumed for their psychoactive effects. Although there are important
differences between Foxy and DET, the similarities in their structures
would put a reasonable person on notice that Foxy might be regarded
as a DET analogue, particularly if that person intended (as Klecker
plainly did) that Foxy be ingested as a hallucinogen.
  3
   See United States v. Orchard, 332 F.3d 1133, 1137-38 (8th Cir.
2003); United States v. Washam, 312 F.3d 926, 930-32 (8th Cir. 2002);
United States v. Fisher, 289 F.3d 1329, 1333-39 (11th Cir. 2002), cert.
denied, 537 U.S. 1112 (2003); Carlson, 87 F.3d at 443-44; United States
v. McKinney, 79 F.3d 105, 108 (8th Cir. 1996), vacated on other
grounds, 520 U.S. 1226 (1997); United States v. Hofstatter, 8 F.3d 316,
321-22 (6th Cir. 1993) (per curiam); United States v. Granberry, 916
F.2d 1008, 1010 (5th Cir. 1990); United States v. Desurra, 865 F.2d 651,
653 (5th Cir. 1989) (per curiam).
6                      UNITED STATES v. KLECKER
   Finally, we note that the district court heard testimony that Klecker
was actually aware that Foxy was a controlled substance analogue.
Some courts have concluded that a defendant who had actual notice
that his conduct was unlawful cannot prevail on a vagueness chal-
lenge. See, e.g., United States v. Washam, 312 F.3d 926, 930 (8th Cir.
2002); United States v. Pitt-Des Moines, Inc., 168 F.3d 976, 990 (7th
Cir. 1999). We need not decide this question, however, because we
conclude that the Analogue Act would not be unconstitutionally
vague as applied to Foxy even with respect to a defendant who lacked
actual notice.

                                   B.

   Klecker next claims that the district court erred in finding that Foxy
is an analogue of DET. We disagree.

   Initially, we note some uncertainty about the procedural posture of
this claim. Whether a particular substance qualifies as a controlled
substance analogue is a question of fact. See United States v. Fisher,
289 F.3d 1329, 1333 (11th Cir. 2002), cert. denied, 537 U.S. 1112
(2003). Questions of fact are generally reviewed for clear error. See
United States v. Elie, 111 F.3d 1135, 1144 (4th Cir. 1997). We are not
certain, however, that this factual question was properly in issue in
the district court. The only hearing held in the district court concerned
Klecker’s motion to dismiss the indictment, and we doubt that an
indictment would be subject to dismissal on the ground that one of its
essential allegations was false. Cf. Costello v. United States, 350 U.S.
359, 363 (1956) (holding that defendant was not entitled to dismissal
of indictment based on inadequacy or incompetence of evidence pre-
sented to grand jury). We are therefore inclined to construe this claim
as a challenge to the adequacy of the factual basis underlying Kleck-
er’s plea, which we would review for abuse of discretion, see United
States v. Martinez, 277 F.3d 517, 531 (4th Cir.), cert. denied, 537
U.S. 899 (2002).

   Ultimately, we need not resolve this question; Klecker conceded at
oral argument that he is not entitled to de novo review, and we con-
clude that the finding of the district court should be affirmed under
any deferential standard of review. In its very careful opinion, the dis-
trict court summarized the evidence from the hearing as follows:
                      UNITED STATES v. KLECKER                       7
    "Foxy" and DET share the same core arrangement of atoms,
    known as tryptamine. Tryptamine is the core element of a
    number of hallucinogenic drugs. DET is created by adding
    two ethyl groups (two carbon chain) to the tryptamine core.
    "Foxy" is produced by adding a methoxy group (CH3O) to
    the number 5 carbon in the phenyl ring (6 carbon ring) and
    changing the diethyl groups (two carbon chain) of DET to
    diisopropyl (three carbon chain with a branching structure)
    . . . . The Court finds that the substitutions to "Foxy" and
    DET, while not identical, are substantially similar. The tryp-
    tamine core is intact and therefore identical in the two com-
    pounds, and the remaining elements are substantially
    similar.

J.A. 536 (footnote omitted); see also id. (explaining that the term
"substitutions" refers to additions to the tryptamine core). The court
further noted that Foxy and DET have comparable hallucinogenic
effects. The record contains ample evidence supporting these conclu-
sions. Accordingly, we affirm the finding of the district court that
Foxy is a DET analogue.

                                 III.

  For the foregoing reasons, we affirm the judgment of the district
court.

                                                          AFFIRMED
