 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued February 17, 2011               Decided April 29, 2011

                         No. 06-3070

                UNITED STATES OF AMERICA,
                        APPELLEE

                              v.

BRYAN BURWELL, AARON PERKINS, MALVIN PALMER, CARLOS
   AGUIAR, MIGUEL MORROW, AND LIONEL STODDARD,
                   APPELLANTS



   Consolidated with 06-3071, 06-3073, 06-3077, 06-3083,
                         06-3084


        Appeals from the United States District Court
                for the District of Columbia
                     (No. 04cr00355-05)



    Robert S. Becker, appointed by the court, argued the issues
Other-Crimes Evidence, Bias Cross-Examination Evidence,
and Motion to Sever. William Francis Xavier Becker,
appointed by the court, argued the issue of Sufficiency of
Machine-Gun Evidence. With them on the briefs were Mary E.
                                2
Davis, Allen H. Orenberg, and David B. Smith, appointed by
the court, A. J. Kramer, Federal Public Defender, and W.
Gregory Spencer, Assistant Federal Public Defender.

    Stratton C. Strand, Assistant U.S. Attorney, argued the
cause for appellee. With him on the brief were Ronald C.
Machen Jr., U.S. Attorney, Roy W. McLeese III, Daniel P.
Butler, and Stephanie C. Brenowitz, Assistant U.S. Attorneys.

       Before: HENDERSON, TATEL and BROWN, Circuit Judges.

       Opinion for the Court by Circuit Judge BROWN.

     BROWN, Circuit Judge: The relatively routine legal
questions presented by this appeal arise from quite an unusual
set of facts. Appellants are modern-day bank robbers whose
old-school tactics—more reminiscent of the brashness of John
Dillinger than the subtlety of Willie Sutton—included
subduing innocent bystanders with gratuitous gunplay, pistol
whipping a victim, and peppering a pursuing police car with
bullets. When the aftermath of their final robbery was captured
on film by a TV station’s news camera crew, the robbers were
apprehended a few weeks later, convicted by jury of numerous
crimes, and sentenced to various terms of imprisonment. They
now assert assorted infirmities in both the trial and their
sentences. We affirm.

                                I

    Because ―brevity is the soul of wit,‖1 we offer only an
abbreviated version of the essential facts underlying this
appeal.     The      six     Appellants,    along      with
co-conspirators-turned-government-witnesses     Nourredine

1
    WILLIAM SHAKESPEARE, HAMLET act 2, sc. 2.
                               3
Chtaini and Omar Holmes, indulged in a violent crime spree
throughout the District of Columbia metro area that lasted for
nearly a year and a half. Appellants, who began by cultivating
and selling marijuana, evolved into a ring that committed
armed bank robberies, using stolen vehicles to travel to the
targeted banks and make their escapes. By the summer of
2004, the robbers had developed a signature style. The gang
wore bullet-proof vests, masks, and gloves, and relied on
superior fire power, preferring to use military weapons like
AK-47s instead of handguns because they surmised the
metropolitan police ―wouldn’t respond‖ when Appellants
―robb[ed] banks with assault weapons.‖ (Tr: 5/10/05PM at
3950). The gang made use of several stolen vehicles,
strategically placed along the get-away-route, for each
robbery. The robbers would serially abandon the vehicles,
often torching them in an attempt to destroy any forensic
evidence that might be left behind.

     After their apprehension, a grand jury issued a
twenty-count indictment charging Appellants with
racketeering conspiracy, armed-bank-robbery conspiracy, 2
four armed bank robberies, two assaults with intent to kill, and
various weapons crimes. Following a lengthy trial, a jury
convicted each defendant of RICO conspiracy under 18 U.S.C.
§ 1962(d) and conspiracy to commit armed bank robbery under
18 U.S.C. § 371. Each defendant was also convicted for his
individual participation in specific bank robberies and of
various firearms offenses. Additionally, Miguel Morrow was
convicted of assault with intent to kill while armed pursuant to
D.C. Code §§ 22-401, -1805, -4502, but Morrow and Lionel


2
  Only the racketeering and armed-bank-robbery conspiracies were
charged against every Appellant. The other crimes were charged
against Appellants in various combinations.
                               4
Stoddard were acquitted of a separate assault with intent to kill
charge.

    At sentencing, the district court prescribed life
imprisonment for Morrow. As for the other defendants,
Stoddard received 725 months’ imprisonment; Carlos Aguiar,
720 months’ imprisonment; Bryan Burwell, 495 months’
imprisonment; Aaron Perkins, 417 months’ imprisonment; and
Malvin Palmer, 512 months’ imprisonment. The court also
sentenced each defendant to a term of supervised release and
ordered the defendants to pay restitution, jointly and severally.
The defendants now appeal, alleging an assortment of errors in
both their trial and sentencing proceedings.

                               II

    Although Appellants raised numerous issues on appeal,
only two of those arguments have arguable merit. We limit our
discussion accordingly.

                               A

     During the trial, the government sought and gained
admission of a hoard of ―other crimes‖ evidence. The
Appellants now argue the admission of this evidence was in
error, both because it was offered for an impermissible purpose
and because its probative value was substantially outweighed
by its prejudicial effect. We disagree.

     Federal Rule of Evidence 404(b) provides: ―Evidence of
other crimes, wrongs, or acts is not admissible to prove the
character of a person in order to show action in conformity
therewith.‖ Nonetheless, such evidence is expressly permitted
―for other purposes, such as proof of motive, opportunity,
intent, preparation, plan, knowledge, identity, or absence of
                               5
mistake or accident.‖ Id. We have described Rule 404(b) as ―a
rule of inclusion rather than exclusion.‖ United States v.
Bowie, 232 F.3d 923, 929 (D.C. Cir. 2000). Even if admissible
under Rule 404(b), however, that evidence is subject to Rule
403’s balancing test: evidence is admissible unless its
probative value is substantially outweighed by its prejudicial
effect. Fed. R. Evid. 403. We review the admission of other
crimes evidence for abuse of discretion. United States v.
Douglas, 482 F.3d 591, 596 (D.C. Cir. 2007). But ―because the
trial court is in the best position to perform the subjective
balancing required by Rule 403,‖ we review its Rule 403
rulings ―only for grave abuse.‖ Id. (quotation marks and
alteration omitted).

     We must first confront Appellants’ argument that before
permitting the government to introduce other crimes evidence,
the district court had ―to rule preliminarily that the jury could
reasonably find . . . by a preponderance of the evidence‖ that
Appellants committed the uncharged acts. Appellants’
Opening Br. at 18. Appellants are correct that when the
government seeks to introduce evidence that a defendant
committed another crime, that evidence is only relevant, and
hence potentially admissible, if a reasonable jury could find by
a preponderance of the evidence that the defendant, and not
someone else, was responsible for the crime. See Huddleston v.
United States, 485 U.S. 681, 690 (1988); see also Fed. R. Evid.
104(b). Because district courts have broad ―discretion in
controlling the order of proof at trial,‖ however, they may
conditionally admit evidence of other crimes subject to the
requirement that the government later introduce sufficient
evidence for the jury reasonably to find that the defendant
committed those crimes. Huddleston, 485 U.S. at 690; see also
Fed. R. Evid. 104(b) (providing that ―[w]hen the relevancy of
evidence depends upon the fulfillment of a condition of fact,‖
the court may admit the evidence ―subject to[] the introduction
                                6
of evidence sufficient to support a finding of the fulfillment of
the condition‖). We thus reject Appellants’ suggestion that the
district court abused its discretion by permitting the
government to introduce other crimes evidence without
reaching a preliminary determination as to whether the
government had presented sufficient evidence to support a
finding that defendants committed the uncharged acts.
Appellants made no objection on conditional relevancy
grounds, and thus, the district court’s failure to make an
explicit sufficiency determination on its own initiative did not
constitute plain error. See Huddleston, 485 U.S. at 690 n.7 (―It
is, of course, not the responsibility of the judge sua sponte to
insure that the foundation evidence is offered . . . .‖ (internal
quotation marks omitted)).

     The evidence admitted under Rule 404(b)3 falls into three
broad categories: evidence of Appellants’ commission of three
carjackings; evidence of Appellants’ theft of forty cars; and
evidence of Appellants’ use of false names, as well as their
marijuana cultivation and distribution. The district court
admitted the evidence of the carjackings, false names, and
marijuana cultivation and distribution for a variety of purposes,
including the theory that it demonstrated Appellants’ modus
operandi and identities. We agree with Appellants that
admission for either of those purposes was improper.

    Although not listed in Rule 404(b)’s nonexclusive list of
proper purposes, modus operandi evidence is normally
admitted pursuant to the identity exception. See United States
3
  The district court primarily admitted the evidence under Rule
404(b). But it also relied on the theories of direct evidence and
inextricable intertwinement evidence. United States v. Morrow, No.
CRIM 04355, 2005 WL 3159572 (D.D.C. Apr. 7, 2005). Because we
find the evidence was admissible under Rule 404(b), we need not
address these other theories of admissibility.
                                7
v. Carr, 373 F.3d 1350, 1353 (D.C. Cir. 2004); United States v.
Crowder, 87 F.3d 1405, 1413 (D.C. Cir. 1996), rev’d on other
grounds, 519 U.S. 1087 (1997). But evidence of modus
operandi must be unique; ―the Government must establish not
only that the extrinsic act bears some peculiar or striking
similarity to the charged crimes, but also that it is the
defendant’s trademark, so unusual and distinctive as to be like
a signature.‖ 4 Crowder, 87 F.3d at 1413 (quotation marks
omitted). The Appellants’ use of violence and weapons is,
unfortunately, not so unique to crimes in the District of
Columbia that it constitutes appropriate modus operandi
evidence.

     Nor was their use of guns and violence so distinctive that it
demonstrated Appellants’ identity. To be relevant to identity,
the other crimes must share similar characteristics with the
charged acts. United States v. Lawson, 410 F.3d 735, 741 (D.C.
Cir. 2005) (admitting other crimes evidence to prove identity
in a charged robbery when, during both the charged and
uncharged robberies, there were two robbers—one tall and one
short, the tall robber wielded a distinctive gun, the short robber
collected the money, and the tall robber wore the same
clothing). As with modus operandi, the naked use of violence
and weapons, without more, does not rise to the level of
similarity necessary to make the other crimes evidence
relevant to identity.

    But just because evidence is inadmissible for one purpose
does not mean it is inadmissible for another. See, e.g., Fed. R.
Evid. 404(b) (explaining that evidence of other acts is
inadmissible for propensity purposes, but admissible for other

4
 Think, for example, of the 1990 Macaulay Culkin movie Home
Alone in which the ―Wet Bandits‖ left the faucets running in each
house they burgled. HOME ALONE (20th Century Fox 1990).
                                8
purposes). The Appellants were charged with violating 18
U.S.C. § 1962(d), which prohibits, among other things,
conspiracies to conduct the affairs of an ―enterprise‖ through a
pattern of racketeering activity. An ―enterprise‖ includes ―any
union or group of individuals associated in fact although not a
legal entity.‖ 18 U.S.C. § 1961(4). Even if the government is
not required to prove the existence of an association under
§ 1962(d), cf. Salinas v. United States, 522 U.S. 52, 65 (1997);
United States v. Hoyle, 122 F.3d 48, 50 (D.C. Cir. 1997)
(explaining a RICO conspiracy ―requires proof that the
defendant agreed to further a substantive RICO violation‖), it
certainly is entitled to do so, see United States v. Mathis, 216
F.3d 18, 26 (D.C. Cir. 2000) (allowing the prosecution
―considerable leeway‖ in proving its conspiracy case through
evidence of other offenses). The Appellants’ offer to stipulate
to their association has no bearing on the government’s
entitlement to prove its case; rather, it is only one factor the
court considers in conducting its Rule 403 analysis. See United
States v. Crowder, 141 F.3d 1202, 1209 (D.C. Cir. 1998) (en
banc). Because evidence of the three carjackings, the stolen
cars, the use of false names, and the marijuana cultivation and
distribution was relevant to prove Appellants’ association, we
see no error in admitting this evidence under Rule 404(b).5
Moreover, considering the nature of the evidence against
Appellants (for example, the bank surveillance video of
Appellants brandishing automatic weapons and pointing them
at customers), the probative value of most of this evidence is
not substantially outweighed by the evidence’s potential for
prejudice. Cf. United States v. Mahdi, 598 F.3d 883, 892 (D.C.
Cir. 2010) (upholding Rule 403 analysis where other crimes

5
  We note that the third carjacking, ―the Southern Comfort‖
carjacking, was properly admitted as direct evidence of the charged
RICO conspiracy, so the alternative theory of admission under Rule
404(b) was unnecessary, but sufficient.
                               9
evidence of an assault with a knife and a stabbing ―paled
alongside the extreme violence of the acts of which [the
defendant] was indicted and convicted‖).

     The one piece of evidence that gives us pause is the
admission of the ―Silver Spring‖ carjacking. This carjacking
incident involved Appellant Morrow, and co-conspirators
Chtaini and Holmes. In November 2003, while driving around
near Silver Spring, the trio decided to steal a Mercedes S5
because Morrow’s brother and chop-shop owner, Romell
Morrow, had informed them he would pay top dollar for a car
of that model. The men encountered one S5, but chivalrously
decided against stealing it because it contained a female
passenger. When they encountered a second S5, this one being
driven by a man, they decided to follow it. The car reached a
back road in Silver Spring, at which point Chtaini, who was
driving, lightly struck the car’s bumper so the driver would
pull over. The three men exited their car wearing masks and
carrying guns. They subdued the driver and jumped into the
S5, only to find the driver’s two grandchildren in the backseat.
The men removed the five-year-old boy and two-year-old girl
from the S5 ―in a gentle way,‖ and then drove away leaving
their old car behind. (Tr. 5/23/05AM at 5223).

     In determining this evidence was admissible under Rule
403, the district court’s explanation is somewhat terse. In fact,
it does not even mention explicitly the possible prejudice
arising from the sympathetic nature of the victims. Morrow,
2005 WL 3159572, at *18. Arguably, the fact that Morrow
forcibly stole a car from a grandfather and his two young
grandchildren could have struck the jurors as particularly
egregious. The district court should have considered this in its
Rule 403 analysis. Nonetheless, we do not think the district
court’s Rule 403 conclusion amounted to grave error. The
prejudice resulting from the carjacking evidence is slight when
                                 10
compared to the evidence of the violent acts for which
Appellants were indicted. 6 Cf. Mahdi, 598 F.3d at 892.
Moreover, the district court gave numerous and careful
limiting instructions, which we think cure any potential
prejudice. United States v. Perholtz, 842 F.2d 343, 361 (D.C.
Cir. 1988) (―[I]t is the law, pure and simple, that jury
instructions can sufficiently protect a defendant’s interest in
being free from undue prejudice.‖ (quoting United States v.
Daniels, 770 F.2d 1111, 1120 (D.C. Cir. 1985) (Starr, J.,
concurring))).

    The district court did not abuse its discretion in admitting
other acts evidence.

                                 B

     Appellant Burwell argues the government presented
insufficient evidence to support his conviction under 18 U.S.C.
§ 924(c)(1)(B)(ii). Section 924(c)(1)(A) provides for a
mandatory consecutive sentence of at least five years for any
person who uses or carries a firearm ―during and in relation to‖
a crime of violence or for any person who possesses a firearm
―in furtherance of‖ a crime of violence. The mandatory
minimum sentence skyrockets to thirty years, however, if the
firearm involved was a machinegun. 18 U.S.C.
§ 924(c)(1)(B)(ii). A machinegun is defined as ―a gun capable
of firing automatically, that is, of firing several bullets with one
pull of the trigger.‖ United States v. Harris, 959 F.2d 246, 257
(D.C. Cir. 1992) (per curiam), overruled on other grounds by
6
  The evidence introduced to prove the indicted acts included the
bank surveillance photos (one of which showed an Appellant
pointing an automatic weapon at a boy and most of them showing
Appellants brandishing automatic assault rifles), the firing of shots
to intimidate bank employees, and the attempted killing of a police
officer.
                               11
United States v. Stewart, 246 F.3d 728, 730–32 (D.C. Cir.
2001); 18 U.S.C. § 921(23) (referencing 26 U.S.C. § 5845(b)).

     Burwell’s § 924 conviction arose out of his participation
in the June 12, 2004 robbery of Industrial Bank. Because the
gun he used was a machinegun, Burwell received the
thirty-year sentence, in addition to his other sentences. He
asserts two arguments on appeal. First, Burwell contends the
government presented insufficient evidence that he carried the
AK-47 with two handles (the machinegun attributed to him)
during the Industrial Bank robbery. Second, he argues that
even if the government satisfied its burden of proof as to his
weapon, the government failed to show he knew the gun was
capable of firing automatically.

     Burwell’s first contention is an attempt to reargue the
facts. Chtaini testified Burwell carried the two-handled AK-47
during the Industrial Bank robbery. Granted, this testimony
arguably conflicts with that of the bank manager. The bank
manager, who admittedly ―did not know much about guns,‖
(Tr: 4/21/05PM at 1916) testified that the man who asked her
for the keys to the vault was carrying the two-handled AK-47,
and Chtaini testified that it was he and Morrow who went to the
vault area. If true, then Burwell could not have been carrying
the AK-47 with two handles. Nonetheless, it is not our
responsibility on appeal to resolve factual discrepancies. That
task falls in the first instance to the jury. Green v. United
States, 289 F.2d 765, 766 (D.C. Cir. 1961) (per curiam) (―In
our jurisprudence the credibility of witnesses and the
derivation of the truth from oral testimony are reposed in the
hearer of the witnesses.‖ (citation omitted)). Where, as here, it
was entirely reasonable for the jury to have credited Chtaini’s
testimony over the bank manager’s, that assessment is beyond
reproach. See Joy v. Bell Helicopter Textron, Inc., 999 F.2d
549, 561 (D.C. Cir. 1993) (explaining where the jury acts
                              12
reasonably, ―[r]esolving [factual] discrepancies . . . is
quintessentially a matter for the jury‖). Because Chtaini was
intimately involved in the planning and execution of the
robbery, the jury reasonably could have credited his testimony
over the bank manager’s, especially as the manager was under
duress and observed the weapons only briefly in comparison to
Chtaini.

     Burwell’s second argument fails on the law. We have
squarely held that a defendant need not know the weapon he is
carrying is a machinegun for a § 924(c)(1) conviction to stand.
United States v. Harris, 959 F.2d 246, 257–59 (D.C. Cir.
1992). In United States v. Harris, we considered whether the
government must prove the defendant knowingly possessed a
machinegun to sustain convictions under § 924(c)(1) and 26
U.S.C. § 5861(d), which proscribes the receipt or possession of
certain firearms, such as machineguns, that are improperly
registered. We agreed that knowledge is a requirement for
conviction under § 5861(d) because, without knowledge, that
statute risked ―criminaliz[ing] acts completely innocuous on
their face [i.e. gun ownership] despite the actor’s ignorance of
the unknown facts that [make] his behavior illegal.‖ Id. at 261.
However, we refused to read a similar mens rea requirement
into § 924(c). Because § 924(c) applies only to those
individuals involved in the commission of violent crimes or
drug trafficking, there is no risk the statute might ensnare
individuals engaged in otherwise innocent conduct. Id. at 259.
We held the government need only show ―the defendant
engaged in drug trafficking [or a crime of violence] and
intentionally used firearms in the commission of [that crime]‖
to obtain a conviction under § 924(c). Id. at 258.

    Burwell insists that Harris has been undermined by two
subsequent Supreme Court cases, Staples v. United States, 511
U.S. 600 (1994) and United States v. O’Brien, 130 S. Ct. 2169
                               13
(2010). Staples, however, merely held that to obtain a
conviction under § 5861(d), the government must prove the
defendant knew the unregistered gun he possessed had the
characteristics of a machinegun. 511 U.S. at 602. This is
exactly the conclusion we reached in Harris; in fact, Staples
cited Harris approvingly. Id. at 620. True, Staples explained
that because ―offenses that require no mens rea generally are
disfavored, . . . some indication of congressional intent,
express or implied, is required to dispense with mens rea as an
element of the crime.‖ Id. at 606 (internal citation omitted).
But we acknowledged this ―presumption in favor of mens rea‖
in Harris. 959 F.3d at 258. We simply concluded that with
regard to § 924(c), Congress intended the mens rea
requirement to attach only to the fact of firearm use, not to the
fact the firearm had the characteristics of a machinegun. Id. at
258. This holding is entirely consistent with Staples, where the
Court worried that reading § 5861(d) to dispense with the mens
rea requirement would criminalize innocent activity. 511 U.S.
at 614–15. Of course, this concern is nonexistent when the
charges—like those brought under § 924(c)—only apply to
criminal activity. Harris, 959 F.2d at 258–59; see also United
States v. Gilliam, 167 F.3d 628, 638 (D.C. Cir. 1999)
(concluding in no uncertain terms, ―Staples does not extend a
special mens rea requirement to § 924(c).‖).

     Burwell also relies on the Court’s recent decision in
United States v. O’Brien, where the Supreme Court held that,
under § 924(c), the fact that the firearm the defendant
possessed was a machinegun ―[was] an element to be proved to
the jury beyond a reasonable doubt,‖ not a ―sentencing factor‖
to be proved to the judge by a preponderance of the evidence at
sentencing. 130 S. Ct. at 2172. Admittedly, Harris is
potentially inconsistent with O’Brien to the extent Harris
referred to § 924(c)’s machinegun provision as a ―sentence
enhancement.‖ Harris, 959 F.2d at 258. But in Harris we also
                              14
described the ―automatic firing capability of a weapon‖ as an
―element of the crime.‖ Id. at 259. Thus, it is unclear what
impact O’Brien has on Harris. But even assuming Harris
incorrectly characterized § 924(c)’s machinegun provision as
an enhancement, that does not tell us whether the government
must prove the defendant knew he was carrying a machinegun.
On this point, Burwell is simply mistaken. O’Brien does not
require the government to prove beyond a reasonable doubt
that ―a defendant knew he was using or carrying a machine
gun, as opposed to a semi-automatic firearm.‖ Reply Br. at 36.
The O’Brien Court expressly refrained from deciding whether
―a defendant who uses, carries, or possesses a firearm must be
aware of the weapon’s characteristics.‖ 130 S. Ct. at 2173. In
the absence of an affirmative statement of the Court, we adhere
to our precedent in holding that conviction under § 924(c) does
not require proof the defendant knew the weapon was a
machinegun. See Bldg. & Constr. Trades Dep’t, AFL-CIO v.
Allbaugh, 295 F.3d 28, 34 n.* (D.C. Cir. 2002) (―[A] panel is
bound to abide by [circuit] precedent until it is overturned by
the court sitting en banc or by the Supreme Court.‖).

     Nor does O’Brien’s characterization of the machinegun
provision as an offense element trigger the ―presumption in
favor of mens rea.‖ Harris, 959 F.2d at 258. This presumption
applies with the most force to ―statutory elements that
criminalize otherwise innocent conduct.‖ United States v.
X-Citement Video, Inc., 513 U.S. 64, 72 (1994). Unlike with
§ 5861(d), § 924(c) does not pose any danger of ensnaring ―an
altar boy [who made] an innocent mistake.‖ Harris, 959 F.2d
at 259.

                              C

    We have fully considered the rest of Appellants’
arguments and find them to be without merit. Appellants’
                              15
arguments contesting the admission of bias/cross-examination
evidence, the denial of their severance motion, the exclusion of
extrinsic evidence, the objections sustained during their
closing arguments, the sufficiency of the evidence supporting
their convictions, and the consecutive nature of their sentences
are rejected.

                              III

    For the reasons stated, the convictions and sentences are

                                                      Affirmed.
