Full opinion text
Opinion for the Court filed by Circuit Judge WALD, Circuit Judge SILBERMAN, and Circuit Judge ROGERS. . WALD, SILBERMAN, and ROGERS, Circuit Judges: According to a 115-eount superseding indictment, appellants McKinley Board, Gregory Thomas, Donnell Williams, Andre Williams, and Derrin Perkins, and nineteen others were players in a sizable conspiracy (the “R Street Crew”) to distribute marijuana, PCP, and cocaine around the intersection of R Street and Lincoln Road in Northeast Washington, D.C. On December 23, 1991, Judge Revercomb divided the 24 defendants into four groups for separate trials; the convictions of the first group, which included the three principal leaders of the gang still alive (Anthony Nugent, Kevin Williams-Davis, and Darryl Williams), were affirmed on appeal in United States v. Williams-Davis, 90 F.3d 490 (D.C.Cir.1996), cert. denied, — U.S. -, 117 S.Ct. 986, 136 L.Ed.2d 867 (1997). Appellants, who were tried in the second group of defendants, contest their convictions and life sentences for various drug-related offenses. We affirm. I. Background A. The Organization Viewed in the light most favorable to the government, the evidence introduced at trial established that by 1983 the R Street Crew had established a single coordinated drug distribution network selling principally PCP and marijuana. Following the familiar pattern, see Williams-Davis at 494; United States v. Childress, 58 F.3d 693, 711 (D.C.Cir.1995), cert. denied, — U.S. -, 116 S.Ct. 825, 133 L.Ed.2d 768 (1996), Nugent, Williams-Davis, and Darryl Williams (and other unindieted leaders) used a number of lieutenants to coordinate the sale of drugs by others (the runners), who were often juveniles. The organization’s lieutenants provided the runners with drugs, collected money from them, and paid them; the lieutenants in turn paid the leaders proceeds from the sales. Many of the lieutenants and runners were close friends or relatives of Nugent, Williams-Davis, Darryl Williams, and others in the organization. In 1987, the group began selling cocaine, which it obtained mostly from connections made by Williams-Davis and Nugent in New York (a total of about 500 kilograms) and in California (about 150 kilograms). The organization would shift configuration slightly as various members (including Nugent and Darryl Williams) were arrested and occasionally did time for drug offenses, but the basic structure — a classic chain conspiracy — held. The organization maintained, and the leaders and lieutenants supervised activities at, a number of locations in the R Street area where drugs were packaged for distribution (one such location was known as “the shop”), as well as several “stash houses” in which packaged drugs were stored to later resupply runners on the street. Search warrants executed from 1983 to 1991 at these locations, many of which were the residences of relatives and friends of members of the R Street Crew, disclosed extensive evidence of drug activity, including large quantities of marijuana, PCP, and cocaine, guns and ammunition, and packaging materials and paraphernalia. The R Street Crew’s activities included bloody and sometimes deadly clashes with rival drug-peddling gangs and others over control of the neighborhood: Alton Clea, a member of a rival gang, was shot and killed, while another member of the Clea group was shot and wounded; Thomas stabbed a rival dealer in the back; a rival drug dealer was shot the day after a dispute with Thomas; members of the organization “shot up” an auto-body repair shop owned by rival gang members, killing one person and wounding others; Board shot a rival gang member from a car in which Donnell Williams was also riding; Board, accompanied by Donnell Williams, attempted to kill another rival gang member; upon discovering cash missing from a room, Board and another member of the organization pointed guns at other members’ heads and forced each member to return singly to the room to return the money; and Donnell Williams and others staged an armed robbery of two women prepared to purchase five kilograms of cocaine. Guns were thus a constant in the organization— among other things, in 1987, a senior member of the Crew attempted to buy guns from an undercover agent of the Bureau of Alcohol, Tobacco, and Firearms, and Board was involved in supplying the organization with guns. The R Street Crew was, not surprisingly, also a target of violence. Each of the appellants was heavily involved in the gang’s drug distribution activities. Thomas was originally one of many runners selling for the organization on a daily basis and was arrested in 1988 for attempted distribution of PCP. By 1988 or 1989 Thomas had become involved in managing runners, and, as noted above, was also involved in the R Street Crew’s use of violence against rival distributors. Board began his involvement with the organization as a runner, but soon was managing runners, and packaging drugs for sale. Board was arrested for possession with intent to distribute cocaine and PCP in 1985 and 1986, and in 1990 and 1991, a government informant made several tape-recorded drug purchases and one gun purchase from Board. Board was actively involved in the group’s use of violence to control the R Street neighborhood. Donnell Williams was eleven when the organization first began distributing drugs in 1983, and was fifteen when he was first arrested for selling drugs in 1987. He was arrested four times between May 1988 and March 1990 for selling drugs, and participated’ in a staged armed robbery and several drive-by shootings which targeted rival gang members. Donnell Williams turned eighteen on December 21, 1989. Andre Williams (the younger brother of Darryl Williams and a cousin of Williams-Davis) was fifteen when he was first arrested in 1984 for selling drugs in the Lincoln Road-R Street area. During 1985 and 1986, Andre Williams continued to sell drugs, was involved in bringing drugs to the stash houses, and supplied drugs to runners. In 1988, Andre Williams was involved in mixing marijuana and PCP, and continued to sell and manage runners. Andre Williams turned eighteen on May 15, 1987. Perkins was selling drugs in the Lincoln Road-R Street area by 1984. Perkins continued to sell marijuana and PCP for the organization until 1986; in 1987, he branched out on his own and the organization became a source from which he purchased large quantities of drugs, which he then resold through his own runners. The demise of the R Street Crew began in 1990 after a member of the gang robbed a New York go-between of his cocaine, prompting the go-between (caught between the R Street Crew and his Colombian suppliers) to turn FBI informant. See Williams-Davis, 90 F.3d at 494. The government was thereby able to tape and present to the jury telephone calls between the informant and leaders of the organization. B. Replacement of Trial Judge and Jury Verdict Shortly after the close of the government’s case, Judge Revercomb became too ill to continue, and Judge Hogan was assigned to continue the case pursuant to Fed. R.Crim. P. 25(a). To familiarize himself with the ease, Judge Hogan had a lengthy telephone conversation with Judge Revercomb; was briefed by Judge Revercomb’s law clerk; read all 44 volumes of the trial transcript; and reviewed all pre-trial and trial motions and motions rulings, some of the physical evidence, Judge Revercomb’s chamber notes, and some transcripts from the trial in Williams-Davis. Appellant Board objected, arguing that Judge Hogan should have read all of the transcripts from the first trial as background material and, even if he were to do so, Judge Hogan still would not have been in a position to judge the demeanor of the witnesses. Taking the objection on behalf of all defendants, Judge Hogan denied it, stating that his review of the materials satisfied Rule 25(a). On February 11, 1993, the jury returned its verdicts. The jury convicted each appellant of conspiracy to distribute and possess with intent to distribute various drugs (the drug conspiracy), 21 U.S.C. §§ 841, 846, and of conspiracy to participate in a racketeer influenced corrupt organization (the RICO conspiracy), 18 U.S.C. § 1962(d). The jury found Board guilty of a substantive RICO violation, 18 U.S.C. § 1962(c), but acquitted the other appellants on this charge. The jury also found Board guilty of six counts of distribution or possession with intent to distribute drugs, 21 U.S.C. §§ 841(a)(1), (b)(1); four counts of use of a communication facility in connection with the drug offenses, 21 U.S.C. § 843(b); one count of employing juveniles to distribute drugs, 21 U.S.C. § 845b (now § 861); assault with intent to kill while armed, D.C.Code §§ 22-501, 22-3202; possession of a firearm during that offense, D.C.Code § 22-3204(b); and unlawful shipment, transportation or receipt of a firearm, 18 U.S.C. § 924(b). Donnell Williams was convicted of one count of distribution of drugs and one count of use of a communication facility in connection with that offense, and Thomas and Perkins were convicted of one count each of employment of juveniles to distribute drugs. The jury acquitted Andre Williams of the four non-conspiracy counts with which he was charged. C. Sentencing In separate hearings held from November 1, 1993, to April 21, 1994, Judge Hogan sentenced eaeh of the appellants to concurrent terms of life in prison without parole and sentenced Board to additional terms in prison for other offenses. Judge Hogan relied on the presentence reports to calculate the total amount of drugs involved in the conspiracy. Specifically, each report calculated the total amount involved — the equivalent of over 1,000,000 kilograms of marijuana — in the same way: • 150 kilograms of crack cocaine supplied by Alvin Buckhalter [the gang’s Los Angeles supplier] to the conspiracy, converted to 30,000 kilograms of marijuana; • 500 kilograms of cocaine supplied by Claude Jiggins [the gang’s New York supplier] to the conspiracy, converted to 100,000 kilograms of marijuana; and • 1,000 kilograms of PCP/marijuana distributed by the conspiracy, converted to 1,000,000 kilograms of marijuana per the Sentencing Guidelines tables. The presentence reports arrived at this last figure as follows: Testimony reflects that the organization sold quantities of liquid PCP, marijuana laced with PCP, cocaine, and on occasion, cocaine base, approximately 12 hours per day, seven days per week, and practically every day of the year. Participants testified that between 1984 and 1990, the organization sold on an average of $9,000 to $30,000 worth of PCP lids (lids = 1 to 1& ounces of PCP) per night. A lid sold for approximately $150, and a one ounce bottle of liquid PCP sold for approximately $300. On the basis of the aforementioned, it is therefore estimated that the organization distributed over 1,000 kilograms of PCP and marijuana. Although the presentence report does not specify how the figure of 1,000 kilograms was calculated, the government offers an explanation in its brief: $9,000 per day (the lowest dollar amount for a single day), divided by $150 per one ounce lid, equals 60 ounces per day; 60 ounces distributed 200 days per year is approximately 340 kilograms per year (one ounce = 28.35 grams); 340 kilograms per year for seven years is 2,380 kilograms— more than twice the amount arrived at in the presentence reports. None of the appellants directly challenge the calculation of the total amount of drugs involved in the conspiracy. We consider first appellants’ challenges to their convictions and then address their sentencing claims. II. A. Donnell Williams’ Jurisdictional Challenge Appellant Donnell Williams argues that because he was a juvenile when he became embroiled in the R Street Crew conspiracy and remained a juvenile for most of the time that he was engaged in illegal activity, the Federal Juvenile Delinquency Act (“FJDA”), 18 U.S.C. § 5031 et seq., forbade his prosecution as an adult absent compliance with its procedural requirements for transfer to the adult criminal system. The FJDA provides that [a] juvenile alleged to have committed an act of juvenile delinquency, ... shall not be proceeded against in any court of the United States unless the Attorney General ... certifies to the appropriate district court of the United States that ... (3) the offense charged is a crime of violence that is a felony or an offense described in [21 U.S.C. § 841] ... and that there is a substantial Federal interest in the case or offense to warrant the exercise of Federal jurisdiction. 18 U.S.C. § 5032. A “juvenile” under the FJDA is a “person who has not [yet] attained his eighteenth birthday, or for the purpose of proceedings and disposition under [the FJDA] for an alleged act of juvenile delinquency, a person who has not attained his twenty-first birthday____” 18 U.S.C. § 5031. “[Jjuvenile delinquency” is “the violation of a law of the United States committed by a person prior to his eighteenth birthday which would have been a crime if committed by an adult.” Id. Viewing the evidence in the light most favorable to the government, Donnell Williams was eleven years old when he began participating in the illegal activities of the R Street Crew. He turned eighteen on December 18, 1989, and was nineteen when he was indicted for his involvement in the conspiracy and for various related substantive offenses. He was convicted of RICO conspiracy (Count 2), narcotics conspiracy (Count 3), unlawful distribution of narcotics on October 22, 1990 (Count 93) and unlawful use of a communications facility on October 22, 1990 (Count 94). The two substantive offenses were acts in furtherance of the narcotics and RICO conspiracies, but they constitute separate crimes from the conspiracy offenses. See United States v. Felix, 503 U.S. 378, 390-91, 112 S.Ct. 1377, 1384-85, 118 L.Ed.2d 25 (1992). The FJDA’s definition of juvenile delinquency clearly does not apply to the two substantive offenses because they were committed after Donnell Williams was eighteen years old; there is no question that it was permissible to prosecute Donnell Williams as an adult for those crimes. On the other hand, both conspiracy offenses began before Williams turned eighteen and ended afterward. Under established circuit precedent, a defendant charged with conspiracy may be tried as an adult even if he first became involved in the conspiracy while still a minor, so long as he continues to participate in the conspiracy after reaching the age of eighteen. See United States v. Strothers, 77 F.3d 1389, 1392 (D.C.Cir.), cert. denied, — U.S. -, 117 S.Ct. 374, 136 L.Ed.2d 263 (1996); see also United States v. Spoone, 741 F.2d 680, 687 (4th Cir.1984), cert. denied, 469 U.S. 1162, 105 S.Ct. 917, 83 L.Ed.2d 929 (1985). Relying on United States v. Chambers, 944 F.2d 1253, 1257 (6th Cir.1991), cert. denied, 502 U.S. 1112, 112 S.Ct. 1217, 117 L.Ed.2d 455 (1992), Donnell Williams argues nonetheless that since “most” of his involvement in the R Street Crew conspiracy took place prior to his reaching age eighteen, he should still benefit from the FJDA. In Chambers, 944 F.2d at 1257, the Sixth Circuit applied the special procedural protections of the FJDA to defendants who “were under eighteen years of age during the greater part of the conspiracy and performed their overt acts in furtherance of the conspiracy while they were between fifteen and eighteen years of age.” Though its literal language is ambiguous and could be construed to lend some support to Williams’ claim, we note that other and later Sixth Circuit decisions involving the identical issue, see United States v. Gjonaj, 861 F.2d 143, 144 (6th Cir.1988); United States v. Maddox, 944 F.2d 1223, 1233 (6th Cir.), cert. denied, 510 U.S. 1206, 114 S.Ct. 1328, 127 L.Ed.2d 675 (1994); United States v. Odom, 13 F.3d 949, 957 (6th Cir.), cert. denied, 511 U.S. 1094, 114 S.Ct. 1859,128 L.Ed.2d 481 (1994), discount any suggestion that the quantum of a defendant’s pre- and post-majority involvement in a conspiracy is relevant for the purpose of determining subject matter jurisdiction so long as the defendant signaled his desire to continue as an active participant after the age of eighteen, and we see no persuasive rationale for any other rule. Additionally, in contrast to the Chambers defendants, Donnell Williams was convicted of two substantive offenses committed in furtherance of the conspiracy after he turned eighteen, surely sufficient indicia of his intent to continue with the R Street Crew. In such circumstances, the FJDA does not bar his prosecution for the conspiracies charged. See Strothers, 77 F.3d at 1392. As we discuss in Section III.D.3 of this opinion, see infra pp. 263-266, an adult conviction for such age-of-majority spanning conspiracies must be based solely on the adult participation in the conspiracy. B. Derrin Perkins’ Challenges to Convictions Appellant Derrin Perkins was convicted of RICO conspiracy, pursuant to 18 U.S.C. § 1962(d) (1984) (Count 2); narcotics conspiracy, pursuant to 21 U.S.C. §§ 846, 841(a)(1) & 841(b)(l)(A)(ii)(II), (b)(l)(A)(iv), (b)(l)(A)(iii), (b)(l)(B)(i) & (b)(1)(D) (1984) (Count 3); and employment of juveniles to distribute drugs, pursuant to 21 U.S.C. §§ 845(b), (a)(1) (1984) (now 21 U.S.C. § 861 (1996)), 841(a)(1) & 841(b)(l)(A)(iv) & (b)(1)(D) (Count 11). On appeal he contends that his convictions must be reversed because the government failed to introduce sufficient evidence to support his conspiracy convictions, there was a material variance between the charged conspiracy and the evidence presented at trial, he was substantially prejudiced by prosecutorial misconduct during opening argument to the jury, and the district court refused to instruct the jury on his theory of defense. We find no basis for reversal of his convictions. 1. Sufficiency of the Evidence for Narcotics Conspiracy Conviction Perkins contends that the government’s evidence of drug activity established only that he participated in illegal drug activity independent of the R Street Crew, and that there was no evidence that he served as a manager, director, or member of the conspiracy for which he was convicted. Viewing the evidence in the light most favorable to the government, as we must, Perkins had long and intricate ties to the R Street Crew. Numerous witnesses testified that Perkins purchased drugs from several of the R Street operators and also sold drugs for them. The government’s evidence included, for example, testimony from Dale Webster who stated that she saw “drug activity” in late 1984 on the corner of Lincoln and R Streets by “a lot of the guys that grew up in the neighborhood,” including Kevin Williams, Anthony Nugent, Darryl Williams, Andre Williams, and Perkins. Kenneth Sparrow testified that in 1985, runners wanting coke would say, “go find Derrin, or something like that.” While Perkins also worked alone in 1986 on Lincoln Road between Quincy and R Streets, and “was a boss of his own,” Sparrow testified that Perkins also sold drugs in 1985 for Andre Jackson, who worked for Williams-Davis and Nugent. Dax Nelson, a long-time drug dealer in the R Street area, confirmed that Andre Jackson and Perkins sold cocaine at Lincoln and R Streets, that he and Perkins sold drugs at First and Quincy Streets every day in 1988 and 1989, and that together they made a lot of money. Nelson further testified that when he began selling PCP in 1988 or 1989, while he normally obtained drugs from Kevin Williams-Davis and others, on one occasion Williams-Davis had run out of PCP and Nelson bought a 16-ounce bottle from Perkins for $2,500. Although Nelson did not always know who sold Perkins his drugs, on one occasion it was Odenga Dyson, who worked for Williams-Davis. The government’s evidence also revealed that Perkins had obtained drugs from the R Street Crew that he sold on his own. Witherspoon testified that after selling drugs for the R Street Crew in 1987, he moved to a different location and was introduced to Perkins and began to sell drugs for him. In the summer of 1988, and for six months thereafter, Witherspoon acted as Perkins’ lookout. Witherspoon recounted Perkins’ various drug-related activities, including an occasion when he saw Perkins give Darrell Williams a large wad of money and was told that Perkins and Darrell Williams were going to the “warehouse,” and an occasion when Perkins told Witherspoon that Anthony Nugent wanted Witherspoon to “do something,” and thereafter Witherspoon made a $5,000 delivery of cocaine to a customer, for which Nu-gent paid him. Other witnesses confirmed Perkins’ relationship with the R Street Crew. Frankie Pelham testified that in 1988, when he decided to branch out on his own, he bought sixteen ounces of PCP and half an ounce of cocaine from Perkins. Stephoun Hartwell testified that he accompanied Pelham to Perkins’ house to buy cocaine twice; the second time, Pelham went into Perkins’ house and reported that Perkins was “cooking it up.” Rosalind Cherry testified that on about ten occasions she accompanied Odenga Dyson, her boyfriend, to deliver bottles of PCP to Perkins. Cherry also saw Dyson receive a bag of money from Perkins. Maurice Brooks claimed that Perkins told him that he had taken a bullet out of Williams-Davis’ leg after a shootout that occurred as part of the R Street Crew’s attempt to put a competitor out of business. Charles Smith testified that he saw Perkins at 319 Rock Creek Church Road, the home of Andre Williams and a central location where the R Street Crew stored and packaged drugs, and that he once saw Perkins speaking with Darryl Williams. There was also testimony that Perkins owned several expensive cars and hid his ownership. Sparrow testified that Perkins drove a Volkswagen Cabriolet and a green Mercedes Benz. Nelson claimed that Perkins’ “Benz” was a 300-E and that Perkins also owned a white Nissan 300Zx. At least three other witnesses confirmed Perkins’ ownership of these cars. Nelson also testified that Perkins had registered the Mercedes Benz in someone else’s name. In addition, a salesman at a local Mercedes Benz dealer testified that Perkins had paid in cash for an expensive auto repair. Finally, there was evidence that Perkins sponsored health club memberships for Nu-gent, Williams-Davis, and Jeffrey Williams, and there were photographs showing Perkins with the leaders of the R Street Crew. Based on this evidence, the government maintains that a reasonable jury could find that Perkins was selling drugs for his own account as well as being part of the hierarchy of the R Street Crew in 1984-85, and further, that his association with the Crew in later years showed that he was part of the drug and RICO conspiracies. Perkins maintains that the evidence showed only that he was an independent dealer, who was “universally described” as not being a member of the R Street Crew. He contends that no inference can be drawn from Dale Webster’s testimony that Perkins sold with the R Street Crew during the early stages of the conspiracy in 1983 and 1984, and that Webster’s testimony on cross-examination demonstrated that he had merely seen Perkins talking with others on a street comer where drugs were sold in a neighborhood in which Perkins had lived most of his life. He also contends that although the R Street Crew targeted rival drug sellers with violence, certain members, including Perkins, were not involved in such attacks. Perkins emphasizes that only Rosalind Cherry testified about his link to R Street Crew drug deliveries and that this activity occurred only during the summer of 1989. He further maintains that Wither-spoon’s testimony confirmed that Perkins and the R Street Crew operated in “eompetiti[on]” with one another. To support his contention that he operated independently, Perkins relies in part on Frankie Pelham’s testimony that when he bought drugs from Perkins in 1988, rather than from Nugent or Williams-Davis, he was confident that the R Street Crew would not become aware of his purchases. Finally, Perkins maintains that Witherspoon’s testimony “contradicts the government’s theory of hierarchical control over a monolithic drug organization,” because, according to Witherspoon, directions and payment for a delivery he made for Nugent and Williams-Davis while “on loan” from Perkins came directly from Nugent, rather than through Perkins. Although a jury could view the evidence as Perkins suggests, it was not required to do so and the evidence, as the government contends, was sufficient for a reasonable jury to find that Perkins repeatedly bought drugs from R Street Crew members, sold in the R Street Crew’s turf without being targeted for retaliation as were the Crew’s rivals, and shared at least one runner with the R Street Crew. Further, contrary to Perkins’ contention that the evidence showed only that he maintained a buyer-seller relationship with the R Street Crew, a reasonable jury could find that his relationship was more extensive and involved the R Street Crew’s overall drug operations. While a mere buyer-seller relationship is insufficient to show conspiratorial activity, where the evidence shows that a buyer procured drugs with knowledge of the overall existence of the conspiracy, he may be found to have entered into the conspiratorial agreement. See United States v. Theodoropoulos, 866 F.2d 587, 594 (3d Cir.1989); United States v. Douglas, 874 F.2d 1145, 1151-55 (7th Cir.), cert. denied, 493 U.S. 841, 110 S.Ct. 126, 107 L.Ed.2d 87 (1989); see also United States v. Sobamowo, 892 F.2d 90, 94-95 (D.C.Cir.1989), cert. denied, 498 U.S. 825, 111 S.Ct. 78, 112 L.Ed.2d 51 (1990); United States v. Morris, 836 F.2d 1371, 1373-74 (D.C.Cir.1988); United States v. Bascaro, 742 F.2d 1335, 1359-60 (11th Cir.1984), cert. denied sub nom. Hobson v. United States, 472 U.S. 1017, 105 S.Ct. 3476, 87 L.Ed.2d 613 (1985). The jury could reasonably conclude, based on Perkins’ long-term, drugrelated contacts with the R Street Crew and his ongoing drug activities in the area under their control, that Perkins was aware of the existence of the R Street Crew and that he directly profited from the existence of the conspiracy by procuring drugs and receiving, at a minimum, cooperation from the organization. See United States v. Dickey, 736 F.2d 571, 582-83 (10th Cir.1984), cert. denied sub nom. Beasley v. United States, 469 U.S. 1188, 105 S.Ct. 957, 83 L.Ed.2d 964 (1985); see also United States v. Bynum, 485 F.2d 490, 496 (2d Cir.1973), vacated and remanded on other grounds, 417 U.S. 903, 94 S.Ct. 2598, 41 L.Ed.2d 209 (1974). Accordingly, Perkins’ sufficiency challenge to his drug conspiracy conviction fails. 2. Sufficiency of the Evidence for RICO Conspiracy Conviction Perkins’ challenge to his RICO drug conspiracy conviction is no more persuasive. Under 18 U.S.C. § 1962(c), it is unlawful for an individual “employed by or associated with any enterprise engaged in, or the activities of which affect, interstate or foreign commerce, to conduct or participate directly or indirectly in the conduct of such enterprise’s affairs through a pattern of racketeering activity....” An “enterprise” includes “any individual, partnership, corporation, association, or other legal entity, and any union or group of individuals associated in fact although not a legal entity.” 18 U.S.C. § 1961(d). See also United States v. Turkette, 452 U.S. 576, 580, 101 S.Ct. 2524, 2527, 69 L.Ed.2d 246 (1981). Section 1962(d) makes it “unlawful for any person to conspire to violate” subsection (c). The government meets its burden of proof to show the existence of an agreement to participate in an unlawful enterprise by showing that the defendant agreed personally to the commission of two or more predicate acts defined by the RICO statute. See United States v. Crosby, 20 F.3d 480, 481 (D.C.Cir.), cert. denied, 513 U.S. 883, 115 S.Ct. 221, 130 L.Ed.2d 148 (1994); United States v. Church, 955 F.2d 688, 694 (11th Cir.), cert. denied sub nom. Coppola v. United States, 506 U.S. 881, 113 S.Ct. 233, 121 L.Ed.2d 169 (1992). Perkins does not dispute that the government presented sufficient evidence to show the existence of the RICO enterprise, namely the R Street Crew, but rather contends that the evidence was insufficient to convict him of RICO conspiracy because the government failed to prove the two predicate offenses and that he participated in the direction and control of the enterprise. Perkins’ first contention is meritless because the government presented sufficient evidence to prove his involvement in the drug conspiracy. His second contention rests on the proposition that the direction and control requirements set forth in Reves v. Ernst & Young, 507 U.S. 170, 113 S.Ct. 1163, 122 L.Ed.2d 525 (1993), apply to a RICO conspiracy. This is a question of first impression in this circuit. In Reves, the Supreme Court held that to be convicted of a substantive RICO offense under § 1962(c), “one must participate in the operation or management of the enterprise itself.” Id. at 185, 113 S.Ct. at 1173. This interpretation, the Court concluded, was supported by the plain meaning of the terms and the context of § 1962(c), as well as the legislative history of the RICO statute. Id. at 177-84, 113 S.Ct. at 1169-73. Specifically, the Court concluded that the term “conduct” as used in § 1962(c) required that defendants be found to exercise “some degree of direction” over the enterprise, id. at 178, 113 S.Ct. at 1169, and that the word “participate” required “some part in that direction.” Id. at 179, 113 S.Ct. at 1170. The Court affirmed the lower court’s view that an accounting firm, engaged in the valuation of a farming cooperative based on yearly audits and financial statements, could not be held civilly liable to the cooperative’s noteholders under § 1962(c) after the cooperative filed for bankruptcy. Id. at 186, 113 S.Ct. at 1172-73. Although the Court indicated that “liability under § 1962(c) is not limited to upper management,” id. at 184, 113 S.Ct. at 1172-73, the Court declined to decide “how far § 1962(c) extends down the ladder of operation....” Id. at 184 n. 9, 113 S.Ct. at 1173 n. 9. The four circuits that have confronted the contention that the management and control test set forth in Reves should apply to RICO conspiracy charges brought under § 1962(d) have split. Prior to Reves, a majority of the circuits had held that § 1962(d) is violated when a defendant agrees to join in the commission of a substantive RICO offense, regardless of whether he agrees to commit personally two predicate acts. See, e.g., United States v. Pryba, 900 F.2d 748, 760 (4th Cir.), cert. denied, 498 U.S. 924, 111 S.Ct. 305, 112 L.Ed.2d 258 (1990); United States v. Rosenthal, 793 F.2d 1214, 1228 (11th Cir.1986), cert. denied sub nom. Stewart v. United States, 480 U.S. 919, 107 S.Ct. 1377, 94 L.Ed.2d 692 (1987); United States v. Neapolitan, 791 F.2d 489, 498 (7th Cir.), cert. denied, 479 U.S. 939, 107 S.Ct. 421, 93 L.Ed.2d 371 (1986); United States v. Joseph, 781 F.2d 549, 554 (6th Cir.1986); United States v. Adams, 759 F.2d 1099, 1116 (3d Cir.), cert. denied sub nom. Mustacchio v. United States, 474 U.S. 906, 106 S.Ct. 275, 88 L.Ed.2d 286 (1985); United States v. Tille, 729 F.2d 615, 619 (9th Cir.), cert. denied sub nom. Tillie v. United States, 469 U.S. 845, 105 S.Ct. 156, 83 L.Ed.2d 93 (1984). The rationale underlying these decisions is that conspiracy to commit a RICO violation should be treated no differently than is conspiracy generally. As the Seventh Circuit points out, requiring in the RICO context that a conspirator agree to participate personally in carrying out the racketeering activities in § 1962(c) would require a “degree of involvement in the affairs of the conspiracy that is not required in any other type of conspiracy, where agreeing to a prescribed objective is sufficient.” Neapolitan, 791 F.2d at 498. Consequently, the Seventh and Eleventh Circuits have held that, notwithstanding Reves, evidence that a defendant has conspired to participate in the operation or management of the enterprise is unnecessary to support a RICO conspiracy conviction under § 1962(d). See United States v. Starrett, 55 F.3d 1525, 1547 (11th Cir.1995), cert. denied, — U.S. -, 116 S.Ct. 1335, 134 L.Ed.2d 485 (1996); United States v. Quintanilla, 2 F.3d 1469, 1484-85 (7th Cir.1993); see also Jones v. Meridian Towers Apartments, Inc., 816 F.Supp. 762, 773 (D.D.C.1993). The Third and the Ninth Circuits have taken the opposite position, viewing Reves’ interpretation of § 1962(e) necessarily to apply as well to conspiracy charges under § 1962(d) to violate § 1962(e). Neibel v. Trans World Assurance Co., 108 F.3d 1123, 1128 (9th Cir.1997); United States v. Antar, 53 F.3d 568, 581 (3d Cir.1995). The view that the usual legal standards applicable to criminal conspiracy should apply to § 1962(d) is in accord with this court’s pr e-Reves statement in Danielsen v. Burnside-Ott Aviation Training Center, Inc., 941 F.2d 1220, 1224 (D.C.Cir.1991) (dictum), that Congress did not intend in § 1962(d) to create a new substantive offense: “[§ 1962(d) ] adds nothing substantive to the law. Rather, it makes it unlawful to conspire to violate any of the preceding three sections.” Yet this statement provides little guidance on whether the distinction drawn by the Supreme Court in Reves applies to a conspiracy charge under § 1962(d). Further, nothing in Danielsen is inconsistent with the interpretation of the Third Circuit in Antar, 53 F.3d at 581, that to avoid eviscerating Reves, the RICO conspiracy provision must be read to provide for conviction only where the defendant conspires to operate or manage the enterprise, and not where the defendant simply conspires with someone who is operating or managing the enterprise. Regardless of which approach this circuit adopts, Perkins’ challenge to his RICO conviction fails. Under the pr e-Reves approach noted in Danielsen, 941 F.2d at 1224, Perkins could not seriously contend that there was insufficient evidence to convict him of RICO conspiracy. Yet even if the court were to apply Reves’ management and control test, Perkins also could not prevail because the evidence showed that he eventually became an essential part of ensuring the continuation of the conspiracy when other leaders were in jail. Therefore, whether the court construes Reves to have left undisturbed longstanding principles of conspiracy law, or alternatively views the Supreme Court’s interpretation of § 1962(c) to require direct involvement in management and operation for conviction of a conspiracy to violate that section under § 1962(d), Perkins has no basis on which to complain that his conviction rests on nothing more than his mere association with the Crew, cf. Ruggiero, 726 F.2d at 921; Winter, 663 F.2d at 1136, given the evidence that Perkins played a key role in the R Street Crew at a level high enough to come within the Reves management and control test. 3. Material Variance Between Indictment and Evidence at Trial Perkins also contends that he was prejudiced by a material variance between the indictment and the evidence at trial, maintaining that the evidence demonstrated the existence of multiple conspiracies and not simply the one drug conspiracy charged in the indictment. See, e.g., Kotteakos v. United States, 328 U.S. 750, 765-66, 66 S.Ct. 1239, 1248-49, 90 L.Ed. 1557 (1946); United States v. Tarantino, 846 F.2d 1384, 1391-92 (D.C.Cir.), cert, denied sub nom. Burns v. United States, 488 U.S. 840, 109 S.Ct. 108, 102 L.Ed.2d 83 (1988). Again, we view the evidence in the light most favorable to the government because this contention presents the question whether a reasonable jury could have found Perkins guilty of each element of the single conspiracy with which he was charged. See Childress, 58 F.3d at 709; United States v. Pou, 953 F.2d 363, 369 (8th Cir.), cert. denied, 504 U.S. 926, 112 S.Ct. 1982, 118 L.Ed.2d 580 (1992); Tarantino, 846 F.2d at 1391-92; United States v. Universal Trade & Indus., Inc., 695 F.2d 1151, 1153 (9th Cir.1983). Perkins confuses two independent claims, neither of which has merit. His contention that witnesses failed to establish that he was aware of the R Street Crew or that his own narcotics dealings were dependent upon that network simply rephrases his sufficiency challenge to his drug conspiracy conviction, which we have concluded is meritless. His second contention, that the government’s failure to prove the existence of an overarching conspiracy resulted in a material and prejudicial variance between the indictment and the proof presented at trial, is unpersuasive because Perkins has neither defined nor identified the several conspiracies that he claims the evidence showed. Even if, as Perkins maintains, Sparrow’s testimony “illuminated the ups and downs of the ‘R’ Street [Crew],” that the organization’s strength and activities may have varied over time does not negate evidence of the existence of an overarching conspiracy. The cases on which Perkins relies are distinguishable because each involved evidence showing the existence of identifiable multiple conspiracies. See, e.g., United States v. Durades, 607 F.2d 818, 819 (9th Cir.1979); United States v. Bertolotti, 529 F.2d 149, 154-59 (2d Cir.1975). Indeed, by acknowledging that the government “presented a number of witnesses who linked Anthony Nugent and Kevin Williams-Davis with West Coast and New York narcotics distribution rings, and from there to the District of Columbia and then on to the ‘R’ Street and Lincoln Road N.E. area,” Perkins comes close to acknowledging the existence of a single overarching conspiracy. In any event, because Perkins fails to explain in what way the government’s evidence fell short of establishing the existence of a single conspiracy, to identify evidence supporting his contention that multiple conspiracies existed, and even to advance his conception of the dates and members of the several conspiracies that he claims operated, his variance challenge fails. 4. Jury Instmction Perkins further contends that the district court erred in refusing to instruct the jury on his theory of defense that the government’s evidence showed multiple conspiracies and possible drug activity by him that was unconnected to the R Street Crew. In his view, the jury instructions failed to address two points essential to his defense: first, that proof of a buyer-seller relationship is insufficient evidence of a conspiratorial agreement, and second, that to convict of conspiracy, the jury had to find, in addition to evidence of the existence of a conspiracy, that he was a member of the same conspiracy charged in the indictment. As a general rule, the refusal to give an instruction requested by the defendant is reversible error only if the instruction is substantively correct, not already substantially covered in other instructions given to the jury, and concerns an important point in the trial such that the failure to give it seriously impairs the defendant’s ability to present effectively his defense. See United States v. Taylor, 997 F.2d 1551, 1558 (D.C.Cir.1993). We find no such error here. Perkins requested the district court to instruct the jury that: It is the position of the defendant Derrin Perkins that he is not a member of the drug or RICO conspiracy that is alleged by the government in this indictment. He has denied any illegal association or agreement with any of the persons the government claims are co-conspirators. He has denied the commission of all of the predicate acts upon which the RICO charge is based. The government has presented several witnesses who claimed to have knowledge of Mr. Perkins’ drug activities. You are instructed that a single sale, distribution or transaction does not constitute the crime of conspiracy to distribute drugs. You are also instructed that a simple buyer-seller relationship alone does not furnish the requisite evidence of a conspiratorial agreement. Thus, you are instructed that if you find that Mr. Perkins committed a single act and nothing more, you must acquit him of the charge of drug conspiracy. If, on the other hand, you find that the defendant Perkins did engage in actions consistent with his membership in a criminal conspiracy, you must find that he was a member of the same conspiracy alleged in this indictment in order to convict him in this case. However, if you find that he was a member of another conspiracy, albeit a conspiracy with the same methods and goals, you must acquit Mr. Perkins of that charge. The district court agreed to give the first paragraph of Perkins’ proposed instruction, but ruled that the second and third paragraphs were covered by other instructions. Perkins responded that he did not want the court to give only the first paragraph of the instruction; if the court was unwilling to give the remaining paragraphs, Perkins stated that he did not want the first paragraph to be included in the jury instructions. Perkins’ requested instruction misstated the law on buyerseller relationships in narcotics conspiracies, and hence the district court properly refused to include it in the instructions to the jury. Instead, the district court properly instructed the jury on the role of buyer-seller relationships in narcotics conspiracies. Perkins proposed that the jury be told that “a simple buyer-seller relationship alone does not furnish the requisite evidence of a conspiratorial agreement,” without also being advised that a buyer may be found to be a member of a conspiracy if he is aware of the structure of the conspiracy and the participation of third parties, and if he profits from and intends to further the conspiracy. See, e.g., Sobamowo, 892 F.2d at 94; Bascaro, 742 F.2d at 1359. In addition, the third paragraph of Perkins’ requested instruction was addressed fully in other instructions given to the jury. Accordingly, because Per- kins’ theory of defense was properly presented in the jury instructions, he fails to show reversible error. C. Andre Williams’ and Derrin Perkins’ Prosecutorial Misconduct Claims Appellants Derrin Perkins and Andre Williams contend that their convictions must be reversed because of prosecutorial misconduct during opening argument to the jury. The touchstone of a prosecutorial misconduct claim is prejudice: the court must consider “the probable effect the prosecutor’s [statements] would have on the jury’s ability to judge the evidence fairly.” United States v. Young, 470 U.S. 1, 12, 105 S.Ct. 1038, 1044, 84 L.Ed.2d 1 (1985). To determine whether improper remarks by the prosecutor have substantially prejudiced a defendant’s trial, the court looks to “the severity of the misconduct, the measures adopted to cure the misconduct, and the certainty of conviction absent the improper remarks.” Williams-Davis, 90 F.3d at 507 (quoting United States v. Monaghan, 741 F.2d 1434, 1443 (D.C.Cir.1984), cert. denied, 470 U.S. 1085, 105 S.Ct. 1847, 85 L.Ed.2d 146 (1985)). As to both appellants, the prosecutor’s opening statement to the jury stated that the government would present evidence that would implicate the defendant in certain criminal activities, no evidence of which was ultimately produced at trial. Regarding Williams, the prosecutor told the jury that the government would show that he was involved in the murder of Joel Mays, a drug operator who was a rival of the R Street Crew. The murder of Joel Mays was charged solely as a racketeering act in the RICO counts in the indictment. When the government failed to present any evidence relating to this murder, the district court dismissed the racketeering act at the close of the government’s case. Williams contends on appeal that he was prejudiced by the government’s statement that it would present evidence to show his role in the Joel Mays murder when no such evidence was introduced at trial. In denying Williams’ motions for a mistrial, the district court found that there was no evidence of bad faith by the prosecutor, who explained that he was unable to present the evidence because the witness upon whom he was relying was uncertain whether Andre Williams or Darryl Williams was present at the murder. The district court also noted that a substantial period of time had lapsed between the time of the opening statement and the time that the jury commenced its deliberations. Finally, the court offered to instruct the jury, if Williams so desired, to disregard the prosecutor’s references to the Joel Mays murder during the opening argument because no evidence on the matter was introduced at trial. During closing argument, Williams’ counsel argued to the jury that the government’s case lacked credibility in light of the government’s failure to produce evidence of Williams’ alleged role in the Mays murder. The district court, in turn, instructed the jury that opening statements were not evidence, and that the jury was not to consider “in any way that allegation [relating to the Joel Mays murder] against Andre Williams. You should not even discuss that allegation during your deliberations.” Regarding Derrin Perkins, the prosecutor stated in his opening argument to the jury that the government would prove sixteen facts at trial to show that Perkins began selling drugs on the street like the other members of the Crew, and rose in the ranks to work at the drug stash house, eventually playing a key role in enabling the conspiracy to continue after other leaders were jailed and enhancing its financial success through a money laundering scheme involving the leasing of expensive automobiles under the names of nominees. Perkins contends that the government provided no evidence regarding some of these facts at trial; as to others, Perkins contends that any evidence of illicit activity was unconnected to him. Most prejudicial, Perkins contends, was the prosecutor’s statement to the jury that after Perkins’ arrest he confessed to an FBI agent that he was guilty of most of the conduct that was later charged in the indictment. In denying Perkins’ motions for judgments of acquittal at the close of the government’s ease-in-chief and at the close of all the evidence, the district court ruled that the prosecutor had represented in opening argument what he in good faith had thought he could prove, that some of the facts could reasonably be inferred from evidence at trial, that in closing argument defense counsel had seized upon the government’s failure to prove the facts promised in the prosecutor’s opening statement, and that, as a result, Perkins suffered no prejudice in light of the evidence introduced by the government at trial. On appeal, the government concedes, as it must, that it failed to produce evidence supporting its opening statement. In Williams-Davis, which involved the trial of high-level members of the R Street Crew, the court characterized similar errors as “severe misconduct.” 90 F.3d at 507. In that case the court also had occasion to observe that “[t]his court has long recognized that a prosecutor is obliged ‘to avoid making statements of fact to the jury not supported by proper evidence introduced during trial.’ ” Id. (quoting Gaither v. United States, 413 F.2d 1061, 1079 (D.C.Cir.1969)). The purpose of an opening statement is to “provid[e] background on objective facts while avoiding prejudicial references____” United States v. Small, 74 F.3d 1276, 1283 (D.C.Cir.), cert. denied, — U.S. -, 116 S.Ct. 1867, 134 L.Ed.2d 965 (1996). In Small, the court quoted with approval the Fourth Circuit’s statement in United States v. Brockington, 849 F.2d 872, 875 (4th Cir.1988), that “[t]he prosecutor’s opening statement should be an objective summary of the evidence reasonably expected to be produced, and the prosecutor should not use the opening statement as an opportunity to ‘poison the jury’s mind against the defendant’ or ‘to recite items of highly questionable evidence.’” 74 F.3d at 1283 (citations omitted). In other words, “[t]he prosecutor’s opening statement should be confined to a statement of the issues in the case and the evidence the prosecutor intends to offer which the prosecutor believes in good faith will be available and admissible[,]” “scrupulously avoiding] any utterance that [the prosecutor] believes cannot and will not later actually be supported with [competent and reliable] evidence.” Id. (quoting ABA Standards for Criminal Justice 3-5.5, commentary at 100 (3d ed.1993)). Consequently, where the prosecutor informs the jury that the government will produce certain evidence to show a defendant’s guilt and then, without good cause, fails to do so, the prosecutor fails to give a proper opening statement to the jury. Otherwise, the risk to the defendant is that the jury’s mindset will be tainted, resulting in an unfair trial. See Williams-Davis, 90 F.3d at 506. The risk to the government is that it may have to retry the ease. It is true, as the government points out, that during closing arguments the defense is free to call to the jury’s attention the fact that the government has failed to present evidence that it promised, and to that extent its case is suspect, being weaker than the jury might originally have thought based on the prosecutor’s opening statement. But this approach places an unfair burden on the defense in cases like Williams’ where, as the district court noted, defense counsel may wish to avoid reminding the jury of activities for which no evidence was offered at trial. Defense counsel might well have preferred to avoid referring to the Joel Mays murder out of concern that doing so would only serve to engrain Williams’ link to this violent act. Given the other evidence of Williams’ involvement with the R Street Crew and its penchant for violence against rival drug operations, defense counsel would undoubtedly be concerned that a special instruction would remind the jury that another murder had occurred and that Williams was likely implicated as a result of the evidence of his working relationship with the R Street Crew. To avoid such difficulties, an opening statement to the jury should be carefully phrased to avoid overstatement, and the prosecutor should refrain from pledging to present highly inculpatory evidence of a defendant’s guilt, unless the prosecutor has carefully cheeked the government’s witnesses to be as certain as is reasonably possible that the promised evidence will be forthcoming at trial. See id. at 507. The prosecutor’s failure to exercise such restraint with respect to the Joel Mays murder is particularly troubling because the prosecutor in the first of the R Street Crew drug conspiracy eases, involving high-level members of the organization, was faulted on precisely the same point, failure to deliver on a promise of evidence that a defendant was implicated in the Joel Mays murder. See id. at 506-07. Moreover, while Williams has not presented any basis for the court to disturb the district court’s finding that there was no evidence of bad faith by the prosecutor, in Perkins’ case, insofar as we are aware, the government easily could have called the FBI agent to testify about Perkins’ confession and it is unclear why the government failed to do so. Any prejudice to Perkins was, arguably, compounded by the number of failures of proof. Having said this, we recognize that the complexity of large, multiple defendant drug conspiracy trials means that prosecutors may overstate their promises of evidence because of genuine confusion about which defendants are implicated in particular conspiratorial activities and as result of the unreliability or equivocation of certain witnesses. See id. (citing Frazier v. Cupp, 394 U.S. 731, 736, 89 S.Ct. 1420, 1423, 22 L.Ed.2d 684 (1969)). In some instances, the complexity of the government’s case may work to a defendant’s benefit. Here, for example, the jury was confronted with a dozen defendants, an indictment with over one hundred counts, and evidence of criminal activity spanning more than a decade. Keeping all of the evidence in mind, much less clearly in mind as to individual defendants, would be a difficult task for any juror where, as here, the trial lasted for more than two months. See Williams-Davis, 90 F.3d at 508. For this additional reason the district court’s evaluation of the three-month lapse between the opening statement and the beginning of the jury’s deliberations supported its ruling that no prejudice resulted from the prosecutor’s improper opening statement. Yet it cannot be gainsaid that a failure by the government to provide proof promised in the prosecutor’s opening statement to the jury adds complexity where clarity is important. While we do not doubt the severity of the misconduct by the prosecutor during the opening statement nor ignore the potential prejudice it may have caused, given the overwhelming evidence of Williams’ and Perkins’ involvement in illegal drug sales and related illegal activities of the R Street Crew, we conclude that the prosecutor’s failures to produce evidence to support the opening statement were harmless. See United States v. Young, 470 U.S. at 19, 105 S.Ct. at 1048; Williams-Davis, 90 F.3d at 507-508; Small, 74 F.3d at 1280. The district court instructed the jury that the arguments of counsel were not evidence, and absent further instruction requested by the defense, such a general instruction suffices to render error in opening statements harmless except in “particularly egregious eases.” Williams-Davis, 90 F.3d at 507 (quoting United States v. North, 910 F.2d 843, 897-98 n. 33 (D.C.Cir.1990), cert. denied, 500 U.S. 941, 111 S.Ct. 2235, 114 L.Ed.2d 477 (1991)). In Williams’ case, the district court gave special instructions to the jury to disregard the mention of the Joel Mays murder. In Perkins’ case, many of the government’s failures to present promised evidence were harmless: six others concerned the same subject, namely whether he had created a scheme to acquire expensive cars to launder drug money and taught leaders of the conspiracy the technique, and two concerned his ownership of the Mercedes Benz, about which there was considerable evidence at trial. Although there is a marginal difference between demonstrating that Perkins bought expensive cars based on his drug sales and showing that he devised the idea and enlisted other members of the R Street Crew in his plans, Perkins fails to demonstrate prejudice. Accordingly, we hold that appellants have failed to show prejudice warranting reversal of their convictions. See Frazier, 394 U.S. at 736, 89 S.Ct. at 1423; Williams-Davis, 90 F.3d at 508. D. Failure to Inform Jury of Andre Williams’ Juvenile Acquittal The district court refused to permit Andre Williams to cross-examine a police officer concerning his acquittal in juvenile court for the conduct that was the subject of Racketeering Act 5, which charged him with possession with intent to distribute PCP, marijuana and cocaine on November 14, 1984. Appellant asserts that the court’s decision violated his Fifth, Sixth and Fourteenth Amendment rights and denied him the opportunity to present his theory that while he may have been in the presence of individuals engaged in drug activity, he was not a part of it. Appellant cites Washington v. Texas, 388 U.S. 14, 87 S.Ct. 1920, 18 L.Ed.2d 1019 (1967), which concerns the right of a defendant to call witnesses in his defense, but we view this claim as asserting a violation of the Confrontation Clause’s guarantee that a defendant may engage in meaningful cross-examination of witnesses. See Davis v. Alaska, 415 U.S. 308, 315-17, 94 S.Ct. 1105, 1109-11, 39 L.Ed.2d 347 (1974). The district court “enjoys wide discretion to control cross-examination.” Harbor Ins. Co. v. Schnabel Found. Co., Inc., 946 F.2d 930, 935 (D.C.Cir.1991), cert. denied, 504 U.S. 931, 112 S.Ct. 1996, 118 L.Ed.2d 592 (1992). Limits on cross-examination amount to an abuse of discretion only if they “result[ ] in prejudice to the substantial rights of the appellant.” Id. The general rule with respect to the type of testimony that appellant sought to elicit is that “a judgment of acquittal is relevant to the legal question of whether the prosecution is barred by the constitutional doctrine of double jeopardy or of collateral estoppel. But once it is determined that these pleas in bar have been rejected, a judgment of acquittal is not usually admissible to rebut inferences drawn from evidence that was admitted.” United States v. Viserto, 596 F.2d 531, 537 (2d Cir.), cert. denied, 444 U.S. 841, 100 S.Ct. 80, 62 L.Ed.2d 52 (1979); Prince v. Lockhart, 971 F.2d 118, 122 (8th Cir.1992) (citing cases), cert. denied, 507 U.S. 964, 113 S.Ct. 1394, 122 L.Ed.2d 768 (1993). The two primary reasons to exclude judgments of acquittal are (1) they are hearsay and (2) they generally are not relevant because they simply show that the government failed to prove guilt beyond a reasonable doubt. United States v. Sutton, 732 F.2d 1483, 1493 (10th Cir.1984), cert. denied, 469 U.S. 1157, 105 S.Ct. 903, 83 L.Ed.2d 919 (1985); United States v. Jones, 808 F.2d 561, 566 (7th Cir.1986), cert. denied, 481 U.S. 1006, 107 S.Ct. 1630, 95 L.Ed.2d 203 (1987). They may also be more prejudicial than probative. United States v. Kerley, 643 F.2d 299, 301 (5th Cir.1981). We find it difficult to conceive how evidence of appellant’s acquittal in juvenile court supports the proposition that, although he “hung out” with friends engaged in drug dealing, he was not himself involved in the illegal conduct. According to appellant’s description of the juvenile proceeding, none of the other juveniles with whom he was tried were convicted in juvenile court; thus the outcome of the juvenile proceeding does not suggest that Andre was a good guy even though the people around him were breaking the law. We see no relevant, non-hearsay purpose for testimony he sought to elicit and we conclude that the district court did not abuse its discretion in excluding the testimony. In his briefs, appellant suggests that the transcript of the juvenile proceeding could have been used to impeach the police officer who testified about the offense during the adult conspiracy trial. Because this argument was not raised below, we consider it waived. E. The Validity of Andre Williams’ RICO Conspiracy Conviction The jury convicted Andre Williams of RICO conspiracy and found that he committed four predicate acts to the RICO conspiracy. One of the predicate acts was Racketeering Act 40, which alleged maintenance of a premise for the purpose of unlawfully manufacturing, storing, distributing and using PCP. The government has conceded that the jury was not instructed on the elements of that offense and that it cannot serve as a predicate act for appellant’s RICO conspiracy conviction. The jury verdict with respect to Racketeering Act 40 therefore is vacated. Appellant argues that Racketeering Act 5, which charged him with possession with intent to distribute PCP, marijuana and cocaine on November 14,1984, should also be vacated because he was found not guilty of the same offense after a juvenile proceeding in the Superior Court for the District of Columbia. Because appellant’s claim rests on his prior acquittal of the offense reproduced in Racketeering Act 5, his claim is one of collateral estoppel, which “bars relitigation between the same parties of issues actually determined at a previous trial____” Ashe v. Swenson, 397 U.S. 436, 442, 90 S.Ct. 1189, 1193, 25 L.Ed.2d 469 (1970). The government contends that the Office of the Corporation Counsel, which prosecuted the juvenile case, is not the “same party” as the Office of the United States Attorney, which is prosecuting the instant litigation, and, therefore, that the doctrine of collateral estoppel is inapplicable. We find it unnecessary