                    FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                      No. 04-10206
                Plaintiff-Appellee,
               v.                                D.C. No.
                                              CR-03-00045-MMC
CLYDELL YOUNGER,
                                                  OPINION
             Defendant-Appellant.
                                          
        Appeal from the United States District Court
           for the Northern District of California
        Maxine M. Chesney, District Judge, Presiding

                    Argued and Submitted
         January 12, 2005—San Francisco, California

                       Filed March 1, 2005

      Before: John T. Noonan, Consuelo M. Callahan,
    Circuit Judges, and Robert E. Jones, District Judge.*

                     Opinion by Judge Jones




   *The Honorable Robert E. Jones, Senior United States District Judge
for the District of Oregon, sitting by designation.

                                2353
2356              UNITED STATES v. YOUNGER


                         COUNSEL

Daniel P. Blank, Office of the Public Defender, San Fran-
cisco, California, for the defendant-appellant.

Kevin V. Ryan, United States Attorney, Hannah Horsley and
Susan R. Jerich, Assistant United States Attorneys, San Fran-
cisco, California, for the plaintiff-appellee.


                          OPINION

JONES, District Judge:

   Clydell Younger appeals his jury conviction for possession
with intent to distribute cocaine base in violation of 21 U.S.C.
§ 841(a)(1) and (b)(1)(B), and for being a felon in possession
of a firearm in violation of 18 U.S.C. § 922(g)(1). Defendant
asserts that (1) the district court erred in denying his motion
to suppress statements; (2) the district court erred in permit-
                  UNITED STATES v. YOUNGER                 2357
ting certain expert opinion testimony; (3) the prosecutors
engaged in prejudicial misconduct during closing argument;
(4) the Second Amendment bars prosecution for felon in pos-
session; and (5) the evidence failed to satisfy the “interstate
commerce” element of the felon-in-possession charge.

   We have jurisdiction pursuant to 28 U.S.C. § 1291, and we
affirm.

I.   Facts

   On November 18, 2002, police officers Hall and Benzinger,
assisted by other officers, executed a warrant to search defen-
dant’s person, residence, and vehicle. The warrant was based
on information Hall and Benzinger received from a confiden-
tial informant that defendant was selling crack cocaine from
his residence.

   After knocking and announcing their presence, the officers
heard loud thumps of someone running inside the residence,
and forced entry. After entry, Hall found defendant in an
upstairs bedroom. Defendant was standing next to an open
window with his right arm outside the window. He was wear-
ing a light blue sweat suit and breathing heavily. Hall arrested
defendant and placed him in handcuffs without incident. Hall
then heard another officer call for his attention. The officer
told Hall that “some guy wearing blue threw a backpack on
the roof.” Hall brought defendant to the window and the offi-
cer stated “[y]eah, that’s the guy.”

   Officers retrieved the backpack and inside it found narcot-
ics and firearms. Specifically, in the large compartment of the
pack officers found a loaded, short-barrel shotgun with two
loose rounds, a loaded revolver in a black holster, a replica
machine gun with an unattached magazine, a black ski mask,
a large folding knife, and a black glove. In the smaller com-
partment, officers found three plastic bags containing 81
smaller bags of crack cocaine, 17 smaller bags of powder
2358                UNITED STATES v. YOUNGER
cocaine, and plastic sandwich bags. Laboratory analysis later
revealed the total amounts of crack and powder cocaine to be
12.5 grams and 4.7 grams, respectively. Officers seized $162
in small denominations from defendant, and also found a
large box of sandwich bags in defendant’s kitchen with smal-
ler bags inside the box.

   After identification of defendant as the one who had thrown
the backpack onto the roof, Hall brought him downstairs to
the living room. There, Hall advised defendant of each of his
Miranda1 rights, including his rights to remain silent and to
have an attorney present before and during questioning, and
asked him if he understood. After every question, defendant
affirmatively acknowledged that he understood each right.

   Meanwhile, Benzinger had detained defendant’s girlfriend
upstairs.2 Before Hall had an opportunity to question defen-
dant, defendant spontaneously stated “that stuff is mine. She
[the girlfriend] don’t know about nothing.” Hall then asked
defendant if the backpack belonged to him. Defendant replied
“everything in the backpack is mine and [she] don’t know
nothing about none of that stuff.” Benzinger entered the living
room with the backpack and asked defendant if the girlfriend
knew anything about the guns in the bag. Defendant
responded “everything in the bag is mine.”

   Officers then transported defendant to the police station,
where he was interviewed. The interview was tape-recorded
and lasted approximately 25 minutes. At the beginning of the
interview the following colloquy took place:

      Hall:          Don’t trip, you’re all good.
  1
   Miranda v. Arizona, 384 U.S. 436 (1966).
  2
   Officers later released the girlfriend as she did not appear to be
involved in criminal activity.
                      UNITED STATES v. YOUNGER                       2359
      Benzinger:       Okay, this is Officer Benzinger, 356.

      Hall:            Officer Hall, 567, the time right now
                       is about, 11:15, and what’s the date?

      Benzinger:       The 18th of November.

      Younger:         But, excuse me, if I’m right, I can
                       have a lawyer present . . .

      Hall:            (interrupting) If you want one.

      Benzinger:       (interrupting) Yeah.

      Younger:         . . . through all this, right?

      Hall:            (interrupting) Yeah. Why don’t we
                       read your Miranda rights, yeah.

      Younger:         Okay, yeah.

Benzinger then read defendant his Miranda rights, asking
after each statement whether defendant understood. Benzinger
did not interpret defendant’s statement as a request for coun-
sel; rather, he considered it “simply him stating one of his
rights, and in fact, he was correct in that, and we told him that.”3

   In the interview that immediately followed, defendant made
various statements, some that were inculpatory and some that
showed that he understood his rights, including the right to
have counsel present. For example, in response to a question
from Hall concerning the backpack, defendant stated:
  3
   At trial, Benzinger testified that his reasons for again advising defen-
dant of his Miranda rights was to capture it on audio tape to create a per-
manent record and to prevent any ambiguity as to whether defendant
understood his rights.
2360              UNITED STATES v. YOUNGER
    The bag? I don’t know about the bag. We’ll talk
    about that in front of a lawyer or something, I don’t
    want to say anything that will incriminate myself in
    court, you know what I’m saying?

    While discussing the weapons found in the backpack,
defendant stated: “You know, I don’t want to say too much
. . . ,” to which Hall responded “[t]hat’s cool, you know, you
can set your own limits and that’s totally fine with us.” At
another point in the interview, defendant stated:

    Yeah, that’s why when I walk, you know, pretty
    much, I’m here, we caught, you know, I know the
    officer’s word is going to be against mine, so we
    might as well talk about it and get it out right here.

Later, defendant acknowledged

    [y]eah, they seen me, they seen me throw it, I might
    as well get it out there, man, I ain’t trying, what I’m
    take this to trial? You know what I’m saying? . . .
    I’m looking for a deal or something, I already know
    I’m looking at a lot of time.

   Defendant was transferred to federal custody on February
3, 2003. On February 14, 2003, he was arraigned in federal
district court on a three-count indictment charging him with
possessing with intent to distribute five or more grams of
cocaine base, felon-firearm possession, and possessing fire-
arms in furtherance of a drug trafficking crime.

   In pretrial proceedings, defendant moved to suppress the
inculpatory statements he made while in custody at the resi-
dence and the police station. The court denied the motion.
Defendant moved to dismiss the firearms-related charges as
unconstitutional under the Second Amendment. The court
denied the motion. Citing Federal Rule of Evidence (“FRE”)
                         UNITED STATES v. YOUNGER                       2361
704(b),4 defendant moved to preclude the government’s
expert witness, a police lieutenant, from offering any opinion
regarding defendant’s intent to distribute the narcotics he pos-
sessed. The court granted the motion in part and denied it in
part, ruling that if the expert conformed his opinions to the
requirements of FRE 704(b), his testimony would be admissi-
ble.

   On October 7, 2003, the jury found defendant guilty on
counts one and two of the indictment, and not guilty on count
three. On March 31, 2004, the district court sentenced defen-
dant to 120 months imprisonment, eight years supervised
release, and a $200 special assessment. Defendant timely
appeals.

II.        Denial of Motion to Suppress

   We review the voluntariness of a waiver of Miranda rights
de novo. United States v. Okafor, 285 F.3d 842, 846-47 (9th
Cir. 2002). Whether the decision was knowing and intelligent
is reviewed for clear error. United States v. Garibay, 143 F.3d
534, 536 (9th Cir. 1998). We review the district court’s fac-
tual findings concerning the words a defendant used to invoke
the right to counsel for clear error and whether the words
actually invoked the right to counsel de novo. United States
v. Ogbuehi, 18 F.3d 807, 812 (9th Cir. 1994).

      a.    Miranda Waiver

      Defendant argues that custodial statements he made at his
  4
      FRE 704(b) provides:
          No expert witness testifying with respect to the mental state or
       condition of a defendant in a criminal case may state an opinion
       or inference as to whether the defendant did or did not have the
       mental state or condition constituting an element of the crime
       charged or of a defense thereto. Such ultimate issues are matters
       for the trier of fact alone.
2362                  UNITED STATES v. YOUNGER
residence and at the police station were taken in violation of
his Miranda rights. His argument is two-fold. First, he argues
that the police officers failed to obtain a valid waiver of his
rights both at the house and the police station. Second, he
contends that the police violated his rights by continuing to
question him at the police station after he invoked counsel.

   A defendant’s waiver of Miranda rights must be “volun-
tary, knowing, and intelligent.” Garibay, 143 F.3d at 536
(internal quotations and citations omitted). A valid waiver
depends on the totality of the circumstances, where under the
circumstances, defendant “was aware of ‘the nature of the
right being abandoned and the consequences of the decision
to abandon it.’ ” Id. (citation omitted).

   A Miranda waiver need not be express. In soliciting a
waiver of Miranda rights, police officers need not use a
waiver form nor ask explicitly whether a defendant intends to
waive his or her rights. United States v. Cazares, 121 F.3d
1241, 1244 (9th Cir. 1997).5 There is, however, a presumption
against waiver. Garibay, 143 F.3d at 536. The burden is on
the government to prove voluntariness, but “ ‘voluntariness of
a waiver’ has always depended on the absence of police over-
reaching, not on ‘free choice’ in any broader sense of the
word.’ ” Cazares, 121 F.3d at 1244 (quoting Colorado v.
Connelly, 479 U.S. 157, 170 (1986)).

   The district court denied defendant’s motion to suppress
following an evidentiary hearing. The court found no express
waiver, but found an implied waiver at the house based on
evidence that after Officer Hall advised defendant of his
Miranda rights but before questioning him, defendant made a
  5
   As previously noted by this Circuit, the police officer’s decision to
forego the simple steps of reading the express waiver language on the back
of the Miranda form and/or requesting an express waiver, while lawful,
“resulted in unnecessary time and effort” and a waste of judicial resources.
Terronova v. Kincheloe, 912 F.2d 1176, 1180 n.13 (9th Cir. 1990).
                  UNITED STATES v. YOUNGER                2363
spontaneous statement and responded to further questioning
without reference to counsel.

   The court analyzed defendant’s statements at the police sta-
tion as a continued conversation at a new location that did not
require another waiver. The court nonetheless found an
implied waiver at the police station based on defendant’s
statements, which the court interpreted as his desire to clear
his girlfriend of any blame. The court also commented that
the officers, who re-advised defendant of his rights after he
asked about counsel, responded to defendant in a way “that
was not unfair.”

   Defendant does not dispute that he understood his rights
but argues that the record is insufficient to overcome the pre-
sumption against waiver. Specifically, he argues that a valid
Miranda waiver requires more than a finding that the suspect
understood his rights and made inculpatory statements. Com-
paring himself to the defendant in Terronova v. Kincheloe,
912 F.2d 1176 (9th Cir. 1990), “an ‘articulate and college-
educated adult’ ” who had demonstrated an ability to assert
his rights and was found to have made a valid implied waiver
of his Miranda rights, 912 F.2d at 1179 (quoting the district
court), defendant faults the district court for failing to make
similar findings concerning his background, experience, and
conduct. See Garibay, 143 F.3d at 536 (holding that the total-
ity of the circumstances includes a defendant’s background,
experience, and conduct). Defendant further contends that his
statement that the backpack belonged to him was not sponta-
neous, but resulted from the “functional equivalent” of inter-
rogation when he was identified as the person who threw the
backpack on the roof.

   [1] With respect to the latter argument, the Supreme Court
held in Rhode Island v. Innis, 446 U.S. 291, 300-01 (1979),
that police actions can amount to the functional equivalent of
questioning. The Court carved out an exception, however, for
actions on the part of the police that are “normally attendant
2364               UNITED STATES v. YOUNGER
to arrest and custody.” Id. at 301. The police identification of
defendant as the person who threw the backpack on the roof
falls squarely within the “normally attendant to arrest and cus-
tody” category of police action. Id.

   As to whether the district court erroneously failed to con-
sider defendant’s background, experience, and conduct, we
clarified in Cazares that such findings are not always required
to support a finding of implied waiver. 121 F.3d at 1244. In
this case, unlike Cazares, there is no evidence that defendant
had language difficulties. The police read each of his rights
twice, and twice he confirmed that he understood each one.
Nor is there evidence that the police coerced or misled defen-
dant into making statements. To the contrary, defendant’s
own statements demonstrate an understanding of his rights
and a desire to waive them.

   [2] We conclude that the district court did not clearly err in
finding that defendant’s conduct in making a spontaneous
statement and continuing to respond to questioning both at the
house and the police station constituted an implied waiver.

  b.   Request for Counsel

   Relying on Davis v. United States, 512 U.S. 452 (1994), the
district court found defendant’s question, “[b]ut, excuse me,
if I am right, I can have a lawyer present through all this,
right?,” to be ambiguous and therefore not sufficient to
require the officers to stop questioning or to seek clarification.
The court further found that nothing the police officers said
after defendant’s question was misleading.

   [3] A suspect who invokes the right to counsel cannot be
questioned unless an attorney is present or the suspect reiniti-
ates the conversation. Edwards v. Arizona, 451 U.S. 477, 484-
85 (1981). Edwards requires courts to “determine whether the
accused actually invoked his right to counsel.” Davis, 512
U.S. at 458 (internal quotations and citations omitted; empha-
                   UNITED STATES v. YOUNGER                    2365
sis in original). The inquiry is objective. Id. at 459. At a mini-
mum, invocation of the right to counsel requires “some
statement that reasonably can be construed to be an expres-
sion of a desire for the assistance of an attorney.” Paulino v.
Castro, 371 F.3d 1083, 1087 (9th Cir. 2004) (internal quota-
tions and citation omitted). To invoke the right to counsel, a
suspect must “unambiguously” request counsel:

    reference to an attorney that is ambiguous or equivo-
    cal in that a reasonable officer in light of the circum-
    stances would have understood only that the suspect
    might be invoking the right to counsel . . . do[es] not
    require the cessation of questioning.

Davis, 512 U.S. at 459 (emphasis in original); accord
Paulino, 371 F.3d at 1087.

   In Clark v. Murphy, 331 F.3d 1062, 1070 (9th Cir. 2003),
a habeas case, we acknowledged that “[o]ur own precedent is
not much help since it is somewhat inconsistent on what con-
stitutes an equivocal request for a lawyer.” Based on a com-
parison of defendant’s statement to those found by the
Supreme Court and this court to be equivocal, however, we
conclude that the district court did not clearly err in finding
defendant’s statement to be ambiguous.

   [4] In Davis, for example, the suspect waived his right to
counsel but later said “[m]aybe I should talk to a lawyer.” 512
U.S. at 455. The Supreme Court held that the statement was
not an unambiguous request for counsel that required ques-
tioning to stop. Davis, 512 U.S. at 462; see also Paulino, 371
F.3d at 1087 (“[w]here’s the attorney” and “[y]ou mean it’s
gonna take him long to come?” not unambiguous requests for
counsel); Clark, 331 F.3d at 1071 (“I think I would like to talk
to a lawyer” not an unambiguous request for counsel); United
States v. Doe, 170 F.3d 1162, 1166 (9th Cir. 1999) (“[w]hat
time will I see a lawyer?” not an unambiguous request for
counsel).
2366              UNITED STATES v. YOUNGER
   By comparison, in Alvarez v. Gomez, 185 F.3d 995, 998
(9th Cir. 1999), we concluded that, when considered together,
a suspect’s three questions — “ ‘(1) Can I get an attorney
right now, man?; (2) You can have attorney right now?; and
(3) Well, like right now you got one?’ ” — constituted an
unambiguous request for counsel. In United States v. Cheely,
36 F.3d 1439, 1448 (9th Cir. 1994), we held that a suspect’s
comment that “my attorney does not want me to talk to you”
in tandem with a refusal to sign a written waiver of the right
to an attorney was an unambiguous request for counsel.

   Defendant urges that his single declarative statement is
comparable to the suspect’s three questions in Alvarez, but we
disagree. Alvarez asked “Can I get an attorney right now?” —
a direct question that “reasonably may be construed to be an
expression of a desire for the assistance of an attorney.” Alva-
rez, 185 F.3d at 998. Moreover, it was “Alvarez’s thrice-
repeated questions, when considered together,” that led this
court to conclude the questions constituted an unequivocal
request for an attorney. Id.

  [5] Because defendant’s words did not unambiguously
invoke the right to counsel, the district court did not err in
denying the motion to suppress.

III.   Admission of Expert Opinion Testimony

  We review a district court’s decision to admit expert testi-
mony for an abuse of discretion. United States v. Alatorre,
222 F.3d 1098, 1100 (9th Cir. 2000). We reverse a district
court’s evidentiary rulings only if “manifestly erroneous.”
United States v. Hankey, 203 F.3d 1160, 1167 (9th Cir. 2000).

   Defendant argues that the government’s expert witness
directly commented on his criminal intent in violation of FRE
704(b). Defendant also argues that the government’s hypo-
thetical questions were improper.
                    UNITED STATES v. YOUNGER                    2367
   The government proffered a police lieutenant as an expert
in the methodology of possession, use, manufacture, and dis-
tribution of illicit narcotic substances. In a letter outlining the
proposed testimony, the government represented that based on
a hypothetical set of facts, the expert would describe the fac-
tors that are relevant to an opinion “that narcotics were more
likely possessed for sale or more likely possessed for personal
use . . . .” In a pretrial ruling, the district court allowed the tes-
timony provided the expert did not state an opinion that
defendant possessed the drugs with intent to distribute them.

  At trial, the expert testified in relevant part as follows:

     Q: Just to make it clear, you don’t have any partic-
     ular knowledge of this defendant or what his intent
     might have been on any day in the past in connection
     with his activities, is that correct:

     A:   That’s correct.

     Q: . . . Now let’s talk about the 81 pieces of crack
     cocaine. If you assume for a moment that they weigh
     an average of .15 grams apiece and that they are 81
     in number, based upon your training and experience,
     do you draw any conclusions about whether — for
     what purpose that a person might possess them?

     A:   Yes, I do.

     Q:   And what conclusion do you draw, sir?

     A: That the individual that possessed these, or shall
     I say, I’ve never known an individual to possess
     these rocks in this size, shape and consistency for
     personal use. I’ve only come in contact with an indi-
     vidual possessing this much narcotics, in this size,
     shape, and consistency, for the purposes of sale.
2368              UNITED STATES v. YOUNGER
                             ***

    Q: . . . Now, if you assume for the moment that
    those 81 rocks were tested and, as a composite, all
    together, were measured to be 68 percent pure
    cocaine base, is that a factor that would enter into
    your opinion in any way?

    A: Yes. Based upon the purity, at street level,
    crack cocaine, it’s a very potent percentage. Usually
    we see crack cocaine between, you know, 50 percent
    or so, which is quite common. So 68 is significant.

       Just the mere number, in and of itself, is a signifi-
    cant fact, in and of itself. I’ve never seen anyone
    possess this much crack for any other reason other
    than to sell it.

    Q: All right, and in connection with the other side
    of [the] picture, the 18 bags, if you assume for a
    moment that those 18 bags each contain approxi-
    mately .26 grams of cocaine hydrochloride, does that
    factor affect — is that a significant factor in you
    coming to your conclusion? Does that push towards
    a sale or push towards personal use?

    A: I’ve never known anyone to possess this much
    narcotics for personal use.

    Q:   Now —

    A: The person, individual, whoever possessed this,
    possessed it for the purposes of selling.

(Emphasis added.) Defense counsel objected at this point and
was overruled. The testimony continued, and the prosecutor
posed this hypothetical question:
                 UNITED STATES v. YOUNGER                  2369
    Q: . . . [A]ssume for a moment that there is found
    inside a residence a backpack with . . . 81 rocks of
    cocaine base, 18 bags of cocaine, inside the same
    container a sawed-off shotgun, a replica submachine
    gun, a Smith & Wesson .357 caliber revolver, both
    of them real guns, loaded, does the absence of any
    of the items that we’ve discussed here named in the
    search warrant, or the absence of most of them,
    detract from your opinion that that amount of
    cocaine, particularly in the presence of the firearms
    and wrapped the way it’s been depicted here, was in
    fact, possessed for sale?

Defense counsel again objected and was overruled. The
expert did not answer the question. Instead, the prosecutor
continued questioning:

    Q: Has it ever come to your attention during your
    26-odd years as a police officer that any crack user
    who was not also a dealer has ever been found in
    possession of a — of 81 rocks of crack cocaine?

    A:   No.

    Q: Have you ever, in your 26 years as a police offi-
    cer, heard of a user of crack cocaine who possessed
    at one time a two-week supply with the idea of just
    storing it up so that he would — he or she would
    have a two-week supply available?

    A:   No.

    Q:   A one-week supply?

    A:   No.

    Q:   A three-day supply?
2370               UNITED STATES v. YOUNGER
    A:    No.

   [6] FRE 704(b) bars an expert from stating “an opinion or
inference as to whether the defendant did or did not have the
mental state or condition constituting an element of the crime
charged . . . .” The rule does not bar testimony supporting an
inference or conclusion that a defendant does or does not have
the requisite mental state, “so long as the expert does not draw
the ultimate inference or conclusion for the jury and the ulti-
mate inference or conclusion does not necessarily follow from
the testimony.” United States v. Morales, 108 F.3d 1031,
1038 (9th Cir. 1997); see also United States v. Gonzales, 307
F.3d 906, 911-12 (9th Cir. 2002) (allowing a narcotic agent’s
testimony that the “ ‘person’ possessing the evidence in ques-
tion would, in fact, possess the drugs for the purpose of dis-
tributing” because it did not compel the jury to reach a
particular conclusion); United States v. Gomez-Norena, 908
F.2d 497, 502 (9th Cir. 1990) (affirming the admission of a
DEA agent’s testimony — that in his opinion the possession
of $200,000 worth of cocaine was consistent with an intent to
distribute rather than with possession for personal use —
because “[a]t no time did [the DEA agent] give his opinion of
what [defendant] actually thought”).

   [7] In this case, the police lieutenant testified only that the
“person” or “individual” who possessed the quantity of drugs
at issue possessed it for the purpose of selling it. He expressly
denied having any particular knowledge about defendant or
what his intent may have been. Thus, his testimony did not
violate FRE 704(b) and the district court did not err in admit-
ting it.

   [8] Defendant further contends that the prosecutor’s hypo-
thetical questions were improper because they “mirrored” the
alleged facts. Defendant concedes, however, that the govern-
ment may ask an expert hypothetical questions regarding the
intent to distribute narcotics of a typical person in roughly the
same situation as the defendant. See Gonzales, 307 F.3d at
                    UNITED STATES v. YOUNGER                    2371
911-12 (upholding admission of expert testimony that the fact
pattern in the case was consistent with an intent to distribute).
Although the prosecutor’s questions brought the testimony
close to Rule 704(b)’s line of prohibition, the expert never
directly commented on defendant’s mental state, and the jury
could have accepted his testimony and still infer that defen-
dant was atypical. Thus, we conclude that the district court
did not abuse its discretion in admitting the testimony.

IV.   Prosecutorial Misconduct

   Where counsel objects to alleged acts of prosecutorial mis-
conduct, we review for harmless error. United States v.
Cabrera, 201 F.3d 1243, 1246 (9th Cir. 2000). A claim of
prosecutorial misconduct is viewed in the entire context of the
trial, and “[r]eversal on this basis is justified only if it appears
more probable than not that prosecutorial misconduct materi-
ally affected the fairness of the trial.” Id. (internal quotations
and citations omitted); accord United States v. Toomey, 764
F.2d 678, 681 (9th Cir. 1985) (determining that any error in
a prosecutor’s statement will not require reversal “unless it is
more probable than not that the error materially affected the
verdict”).

   Defendant contends that the prosecutors6 materially preju-
diced his trial by improperly vouching for his guilt during
closing argument in three ways: by stating a belief that defen-
dant possessed the cocaine for sales purposes, by using the
phrase “we know” in summarizing facts showing defendant’s
guilt, and by making reference to the district court’s pretrial
rulings.

   Improper vouching “ ‘consists of placing the prestige of the
government behind a witness through personal assurances of
the witness’s veracity, or suggesting that information not
  6
  Two prosecutors shared the closing arguments. For ease of reference,
we will refer to them in the plural as “prosecutors.”
2372              UNITED STATES v. YOUNGER
presented to the jury supports the witness’s testimony.’ ”
United States v. Leon-Reyes, 177 F.3d 816, 822 (9th Cir.
1999) (quoting United States v. Necoechea, 986 F.2d 1273,
1276 (9th Cir. 1993)). “It is not misconduct for the prosecutor
to argue reasonable inferences based on the record.” Cabrera,
201 F.3d at 1250 (internal quotations and citation omitted).

   [9] Defendant first points to the prosecutors’ statement, in
addressing count one, that “the government believes that he
did possess cocaine and cocaine base for sales purposes.”
Defense counsel immediately objected to that statement, and
the court sustained the objection. The prosecutors immedi-
ately rephrased it, stating “[w]hat the evidence will show is
that [defendant] possessed 81 rocks of cocaine base and 18
bags of powder for sales purposes,” and continued with clos-
ing argument. In view of the prosecutors’ immediate rephras-
ing of the statement and in the context of the trial as a whole,
we conclude that the single improper expression of belief did
not materially affect the verdict and was, therefore, harmless.
Toomey, 764 F.2d at 681.

  Defendant also contends that the prosecutors improperly
vouched by repeatedly using the phrase “we know” in sum-
marizing the facts showing guilt, e.g., “[w]e know [defendant]
possessed the backpack. We know that. We know inside the
backpack were the 81 rocks wrapped for retail sale and the 18
packets of cocaine powder also wrapped for sale” and “[w]e
know that in the neighboring compartment, the bigger com-
partment, they had two loaded firearms.” Defense counsel
objected to the use of “we know” as suggestive. After deter-
mining that the prosecutors meant “ ‘we know’ from the evi-
dence collectively,” the district court overruled the objection.

   [10] We do not condone the prosecutors’ use of “we know”
statements in closing argument, because the use of “we know”
readily blurs the line between improper vouching and legiti-
mate summary. The question for the jury is not what a prose-
cutor believes to be true or what “we know,” rather, the jury
                  UNITED STATES v. YOUNGER                  2373
must decide what may be inferred from the evidence. We
emphasize that prosecutors should not use “we know” state-
ments in closing argument.

  [11] Nonetheless, the record in this case confirms that the
prosecutors used the phrase “we know” to marshal evidence
actually admitted at trial and reasonable inferences from that
evidence, not to vouch for witness veracity or suggest that
evidence not produced would support a witness’s statements.
Leon-Reyes, 177 F.3d at 822. The prosecutors’ statements
thus were not improper. Cabrera, 201 F.3d at 1250; Toomey,
764 F.2d at 681. Moreover, in the context of the entire trial,
we conclude that the prosecutors’ use of “we know” did not
materially affect the verdict. See Toomey, 764 F.2d at 681.

   Defendant also contends that the prosecutors’ references to
the court’s in limine rulings improperly suggested that the
admitted evidence was reliable. The relevant portions of clos-
ing argument are as follows:

    Prosecutor: . . . The police officer’s job, interview
    a suspect. Do so in a lawful constitutional way,
    which is what they did in this case. Because let me
    assure you, ladies and gentlemen, if they hadn’t, her
    honor is a gatekeeper —

    The Court: Excuse me. You are not to refer to any
    rulings that the court has made.

                            ***

    The Court: You can refer to what the court has
    done in the courtroom, but not what the court has
    done elsewhere.

During the rebuttal portion of the government’s closing argu-
ment, the following took place:
2374             UNITED STATES v. YOUNGER
    Prosecutor: [I]n terms of the corroboration of what
    happened that day and what, in fact, the actions of
    the defendant mean, we can turn to the defendant’s
    statement.

       Counsel suggests there was unfairness in the fact
    that the defendant asked:

        “A. But excuse me. If I’m right, I can
        have a lawyer present?”

        “Q.   If you want one.”

        “A.   Yeah.”

    And then it goes on and he was fully read his
    Miranda rights.

       This court has ruled that —

    The Court:         Excuse me, Mr.

    Defense Counsel: Objection, Your Honor.

    The Court:         I have already admonished [the
                       other prosecutor] about this . . . .
                       I trust you were paying attention
                       to her closing argument and the
                       court’s remarks during them.

       There are to be no references by any counsel to
    any ruling that the court has made other than rulings
    possibly, if you could work them into your argument
    in some legitimate way, that were made here in open
    court.

                           ***
              UNITED STATES v. YOUNGER                   2375
The Court:         And in most instances no counsel
                   should be making any references
                   to the court’s rulings.

Defense Counsel: Could the court offer a corrective
                 instruction that it is the jury’s
                 place to determine the voluntari-
                 ness of the statement, Your
                 Honor?

Prosecutor:        The court ruled —

Defense Counsel: Objection, Your Honor.

The Court:         [To the prosecutor] in a moment
                   I’m going to send the jury out.
                   This is not a matter for discus-
                   sion, all right?

   Is it your intent to make reference to matters that
are contrary to the ruling that I just made?

Prosecutor:        No, Your Honor.

The Court:         Fine. All right.

   Ladies and gentlemen, you ultimately will be the
determiners of all facts that are presented to you and
all issues that are raised.

   So that in this instance to the extent that there
were any remarks made by the defendant or by the
officers themselves that bear in any way on his state
of mind as you view it in reviewing his interview on
tape, you may consider those.

   Ultimately the decisions will be yours as to the
significance of anything that he did say in the course
of that.
2376               UNITED STATES v. YOUNGER
   [12] Thus, the district court cut off the prosecutors’ com-
ments before any pretrial rulings were revealed, and gave the
jury the curative instruction defense counsel requested. The
district court’s attentiveness and swift corrective action thus
prevented the prosecutors’ improper comments from materi-
ally affecting the verdict, and the prosecutors’ misconduct in
referring to the court’s rulings was harmless.

V.     Felony-Firearm Possession

   Before trial, defendant moved to dismiss the firearm-related
counts as unconstitutional under the Second Amendment. The
district court denied the motion. During trial, defendant
requested a modified version of Ninth Circuit Model Instruc-
tion 8.59, which instructs on the elements of 18 U.S.C.
§ 922(g), to require the jury to find that defendant possessed
the firearms “in or affecting” interstate commerce. The court
denied the request, and also denied defendant’s motion for
judgment of acquittal based on sufficiency of the evidence of
interstate commerce.

   The constitutionality of a statute is a legal question of law
that we review de novo. See United States v. Jones, 231 F.3d
508, 513 (9th Cir. 2000). We review a district court’s jury
instructions regarding the elements of a statutory crime de
novo. United States v. Rivera-Belle, 322 F.3d 670, 674 (9th
Cir. 2003). Where defendant preserves a claim of insufficient
evidence by moving for acquittal at the close of evidence, we
review denial of the motion de novo. United States v. Munoz,
233 F.3d 1117, 1129 (9th Cir. 2000).

   Based on our current case law, defendant’s Second Amend-
ment challenge to the constitutionality of § 922(g) is without
merit. See Silveira v. Lockyer, 312 F.3d 1052 (9th Cir. 2002)
(ruling that the Second Amendment does not confer an indi-
vidual right to possess arms), cert. denied 540 U.S. 1046
(2003); see also United States v. Everist, 368 F.3d 517, 519
(5th Cir. 2004) (rejecting a Second Amendment challenge to
                     UNITED STATES v. YOUNGER                       2377
the felon-firearm possession statute and holding that
§ 922(g)(1) “represents a limited and narrowly tailored excep-
tion to the freedom to possess firearms, reasonable in its pur-
poses and consistent with the right to bear arms protected
under the Second Amendment”).

   Defendant’s argument that the jurisdictional element of
§ 922(g) requires proof that the firearm either recently moved
across state lines or that defendant’s conduct had an actual
economic impact likewise lacks merit: “A one-time past con-
nection to interstate commerce is sufficient under
§ 922(g)(1).” United States v. Beasely, 346 F.3d 930, 936 (9th
Cir. 2003); see also United States v. Casterline, 103 F.3d 76,
77 (9th Cir. 1996).

   Defendant relies on United States v. Morrison, 529 U.S.
598 (2000), and United States v. Lopez, 514 U.S. 549 (1995),
characterizing those cases as fatally undermining the model
instruction’s approach to the jurisdictional element. This court
has, however, expressly and repeatedly rejected defendant’s
reading of the law, even after Morrison and Lopez were decided.7
See, e.g., United States v. Rousseau, 257 F.3d 925, 932-33
(9th Cir. 2001) (finding past connection to interstate com-
merce sufficient for § 922(g) conviction). The evidence in this
case was undisputed that defendant’s guns were manufactured
in Massachusetts and found in California. Consequently, the
district court’s jury instruction was proper and the evidence
sufficient to sustain defendant’s conviction on count two.

  AFFIRMED.
   7
     Neither the Gun-Free School Zones Act, 18 U.S.C. § 922(q), invali-
dated in Lopez, nor the Violence Against Women Act, 42 U.S.C. § 13981,
invalidated in Morrison, contained a jurisdictional element to ensure that
the prohibited acts affected interstate commerce. See generally Morrison,
529 U.S. 598, and Lopez, 514 U.S. 549; accord Jones, 231 F.3d at 514
(affirming constitutionality of § 922(g) and distinguishing Lopez and Mor-
rison).
