concurring in part and dissenting in part:
I join the majority’s disposition of Ferguson’s cross-appeal. However, because I believe the district court abused its discretion by empaneling itself as a thirteenth juror to overturn the jury verdict convicting Ferguson of conspiracy to commit murder in aid of racketeering, under 18 U.S.C. § 1959(a)(5), I would reverse the district court’s grant of a new trial on that count. The evidence was fully sufficient, in my view, for a rational jury to find beyond a reasonable doubt that Ferguson was either 1) maintaining or advancing his position in Power Rules, or 2) acting for pecuniary gain as a hired “hit man.” I therefore respectfully dissent from the majority’s rejection of the government’s appeal.
I. The Rule 33 Standard
The majority correctly states that a district court may void a jury verdict and order a new trial under Fed.R.Crim.P. 33 only to prevent “manifest injustice.” See *139United States v. Sanchez, 969 F.2d 1409, 1414 (2d Cir.1992). The majority is also correct that, in proper circumstances, the district court may weigh the evidence and assess the credibility of witnesses. See id.; 3 Charles Alan Wright, Federal Practice and Procedure § 553, at 245-46 (2d ed.1982). Some courts in other circuits have gone so far as to suggest that Rule 33 envisions that a district court will assess the weight of the evidence sitting as a “thirteenth juror.” See, e.g., Brodie v. United States, 295 F.2d 157, 160 (D.C.Cir.1961); United States v. Turner, 490 F.Supp. 583, 593 (E.D.Mich.1979). The metaphor has been used in this circuit in at least one civil case. See Binder v. Commercial Travelers Mut. Accident Ass’n of Am., 165 F.2d 896, 902 (2d Cir.1948).
Like many legal metaphors, the “thirteenth juror” analogy lacks precision. It fails to convey the considerable circumspection that this court has required of district courts’ decisions on Rule 33 motions based on the weight of the evidence. “It has long been our rule that trial courts ‘must defer to the jury’s resolution of the weight of the evidence and the credibility of the witnesses.’ It is only where exceptional circumstances can be demonstrated that the trial judge may intrude upon the jury function of credibility assessment.” Sanchez, 969 F.2d at 1414 (quoting United States v. LeRoy, 687 F.2d 610, 616 (2d Cir.1982)). As long as the evidence is sufficient to let the jury decide the question, the district court may not supplant the jury’s finding of no reasonable doubt with its own finding that reasonable doubt exists. Rather, a new trial should be granted “only in exceptional cases in which the evidence preponderates heavily against the verdict,” 3 Wright, supra, § 553, at 248, such that the only rational outcome is acquittal.1 “There must be a real concern that an innocent person may have been convicted.” Sanchez, 969 F.2d at 1414; see also United States v. Morales, 902 F.2d 604, 606 (7th Cir.1990) (Posner, J.) (describing order of new trial as a response to “a serious danger that a miscarriage of justice has occurred — that is, that an innocent person has been convicted”).
For the reasons that follow, I do not believe that this is the kind of “exceptional case” in which a new trial is warranted on the basis that the evidence was so manifestly imbalanced that the jury plainly and grievously erred and convicted an innocent man. To the contrary, I believe the jury’s determination of guilt was amply justified.
II. Ferguson’s Motive
The majority concludes that Ferguson’s motive for participating in Power Rules’ effort to murder Ayala was neither to maintain or advance his position in the Power Rules organization nor to achieve pecuniary gain. I disagree. The evidence shows that his motive must have been one or the other. The majority’s narrow application of 18 U.S.C. § 1959’s motive requirement is unjustified given the facts of the case and our repeated holding that “section 1959 is to be construed liberally in order to effectuate its remedial purposes.” United States v. Mapp, 170 F.3d 328, 335 *140(2d Cir.1999) (citing United States v. Concepcion, 988 F.2d 369, 381 (2d Cir.1992)).
The majority finds first that Ferguson was not a member of Power Rules, and then, a fortiori, that he was not seeking to maintain or advance his position in the organization. However, there was considerable evidence of Ferguson’s association with Power Rules, and much of that evidence also supports the conclusion that Ferguson was seeking to maintain or advance that association.
A person need not be a formal member of a criminal enterprise to come within the broad ambit of § 1959. Those organizations rarely, if ever, maintain tangible indi-cia of membership found in legitimate business organizations, such as membership rosters, membership cards, official titles, or personnel records. Membership in a criminal organization is far more elastic and informal, a fact reflected in § 1959’s definition of a criminal enterprise as a “group of individuals associated in fact.” 18 U.S.C. § 1959(b)(2). The majority’s emphasis on “formal” membership in Power Rules ignores this definition and its insight about the structure of criminal organizations. See ante at 136.
The government adduced considerable evidence that Ferguson was “associated in fact” with Power Rules: Ferguson participated in three separate attempts to kill Ayala (including the attempted murder of Mercado, whom the assailants believed to be Ayala), whose elimination as leader of a rival gang was believed by Power Rules’ leader, Guzman, to be critical to Power Rules’ success. In each instance, Ferguson worked alongside others who were acknowledged members of Power Rules. The equipment he carried, guns and bullet-proof vests, was not his own; it was supplied by Guzman. Ferguson did not act on his own or direct others. He and the other Power Rules members with him followed Guzman’s directives. Finally, the jury heard testimony that Ferguson received a wad of cash from Guzman.
That there was no evidence linking Ferguson to Power Rules’ day-to-day retail drug trade is beside the point. A criminal organization, like any other, may involve a refined division of labor such that some members perform functions that are not inherently a part of the organization’s primary business. Specializing in violence rather than drug distribution does not preclude membership in an organization that, while deriving its revenues from drug sales, depends on both.
Membership in Power Rules is not enough, of course; Ferguson must also have been seeking to maintain or advance his position in the organization. We have held that the phrase “ ‘maintaining or increasing position’ should be construed liberally.” United States v. Rahman, 189 F.3d 88, 127 (2d Cir.1999) (citing Concepcion, 983 F.2d at 381). “Self-promotion need not have been the defendant’s only, or even his primary, concern, if [the underlying offense] was committed ‘as an integral aspect of membership’ in the enterprise,” United States v. Thai, 29 F.3d 785, 817 (2d Cir.1994) (quoting Concepcion, .988 F.2d at 381). This reading of § 1959 is informed by the statute’s legislative history. See Concepcion, 983 F.2d at 381 (quoting S.Rep. No. 98-225, at 304, reprinted in 1984 U.S.C.C.A.N. at 3483).
The foregoing evidence also shows that Ferguson’s participation in the mission to kill Ayala was undertaken with the purpose of maintaining or increasing his position in the organization. First, in working closely with other members of Power Rules in seeking out Ayala, Ferguson participated in “part of a premeditated plan to accomplish a shared objective.” United States v. Diaz, 176 F.3d 52, 95 (2d Cir.1999); see also Rahman, 189 F.3d at 127 *141(holding that defendant’s crime was “in furtherance of’ membership in the criminal organization in part because the crime was carried out with other members of the organization). Second, Ferguson’s acting at Guzman’s direction and using Guzman’s equipment is also probative of a motive to maintain or increase his position within Power Rules. See Mapp, 170 F.3d at 336.
Third, the importance of the mission to the Power Rules organization suggests that Ferguson’s standing within the enterprise would be secured by his success. Moreover, the elimination of Ayala as a competitor, with Ferguson leading the operation, would directly advance the interests of Power Rules by protecting its position in the local drug market and in turn would advance Ferguson as an associate-in-fact of the organization. Cf. United States v. Tipton, 90 F.3d 861, 891 (4th Cir.1996) (finding that defendant participated in killing in part to maintain position in a drug gang because he “acted ... as a member of the enterprise in furthering its policies of retaliatory violence against any who sufficiently antagonized any of its members”). Given our traditionally liberal reading of “maintain or increase” and the holdings in the analogous eases of Rah-man, Diaz, Mapp, and Tipton, the evidence here easily justified the jury’s verdict.
Notwithstanding the foregoing, the majority concludes that the weight of the evidence indicated that Ferguson was not attempting to maintain or enhance his association with Power Rules. Even if the majority were correct, the evidence surely was sufficient for the jury to find that Ferguson was retained by the organization as an outside “hit man” for monetary gain. This pecuniary motive supports his conviction under 18 U.S.C. § 1969 even absent a finding of membership in Power Rules. Indeed, the majority concedes that “the weight of the evidence showed that Ferguson was an outside hit man.” Ante at 135 (emphasis added); .see also ante at 135-36. If Ferguson was in fact an outside “hit man,” one could fairly infer that he was paid for his work and thus that the motive for his participation was pecuniary. Yet the majority ultimately finds the evidence of this motive insufficient after concluding that the one observed cash pajunent from Guzman to Ferguson was too remote in time from the attempts to murder Ayala.
In so doing, the majority loses sight of the evidence as a whole and particularly the evidence it cited for the proposition that Ferguson was not a member of Power Rules. Either Ferguson was an outside “hit man” acting, with a pecuniary motive of which the receipt of cash was evidence (if not of a quid pro quo. payment, then that he was “in it for the money”), or, as I believe, he was an associate-in-fact of Power Rules and was seeking to advance or maintain his position in the organization, again driven by pecuniary gain. Any other theory is simply implausible. Absent membership or pecuniary motive, Ferguson must have participated in Ayala’s intended murder, with all the risks that entails, solely out of friendship for Guzman. Similarly, if the. money Guzman gave him was unrelated either to Ferguson’s effort to kill Ayala or other enterprise activity, it must have been, in effect, a gift.2 These possibilities border on the fanciful given the context: a large-scale, violent drug enterprise.
*142Accordingly, I respectfully dissent from the majority’s disposition of the government’s appeal. I concur with the majority’s disposition of Ferguson’s cross-appeal.
. The standard I describe differs from that applicable to a Rule 29(c) motion for judgment of acquittal, becaúse, on a Rule 29(c) motion, the district court must view the evidence in the light most favorable to the government. See United States v. Guadagna, 183 F.3d 122, 129 (2d Cir.1999). Consequently, a guilty verdict might survive a Rule 29(c) motion-because a rational jury, viewing the evidence through the government's eyes, could convict-but fail to meet the Rule 33 standard because the momentum of the evidence as a whole would make a guilty verdict irrational.
. The majority hypothesizes that the payment could have been for "a criminal purpose unrelated to Ayala.” Ante at 137. But unless that criminal purpose was also unrelated to Power Rules, an improbable hypothesis without evidential^ support, the payment is evidence of membership in the gang.