Full opinion text
MAHONEY, Circuit Judge: Appellants Victor Torres (“V. Torres”), George Torres (“G. Torres”) (collectively the “Torres brothers”), Nelson Flores (“Flores”), Jesus Santiago (“Santiago”), Louis Rivera (“L. Rivera”), Natalie Vazquez (“N. Vazquez”), Fernando Padrón (“Padrón”), Dennis Rivera (“D. Rivera”), Reginald Velez (“Velez”), Pedro Cruz (“Cruz”), Efrain Arcelay (“Arcelay”) and Raymond E. Coffie (“Coffie”) appeal from judgments of conviction for various violations of the federal narcotics, firearm and tax laws entered, after a jury trial, in the United States District Court for the Southern District of New York, John M. Walker, Jr., Judge. A thirty-two count indictment, S 87 Cr. 593, filed on January 21, 1988, charged that the twelve appellants were members of a multimillion dollar, street level heroin organization (the “Torres Organization” or the “Organization”) which functioned primarily in the South Bronx. Count one charged all defendants with conspiring to distribute, and to possess with intent to distribute, more than a kilogram of heroin in violation of 21 U.S.C. § 846 (1988). Counts two through four charged V. Torres, G. Torres and Flores, respectively, with operating a continuing criminal enterprise in violation of 21 U.S.C. § 848(a) and (b) (1988). Counts five through eleven charged various defendants with distributing heroin, or possessing heroin with the intent to distribute it, in violation of 21 U.S.C. § 841(a)(1) (1988) and related provisions. Counts twelve and thirteen charged Flores and D. Rivera with possession of cocaine with intent to distribute it in violation of 21 U.S.C. § 841(a)(1) (1988) and related provisions. Counts fourteen through eighteen charged various defendants with using and carrying a firearm in connection with drug trafficking in violation of 18 U.S.C. § 924(c)(1) (1988). Counts nineteen and twenty charged Flores, and count twenty-one charged L. Rivera, with making apartments controlled by them available for the unlawful manufacture, distribution and storage of heroin in violation of 21 U.S.C. § 856 (1988). Counts twenty-two through twenty-nine charged the Torres brothers with tax evasion for the years 1983 through 1986 in violation of 26 U.S.C. § 7201 (1982). Counts thirty through thirty-two charged the Torres brothers, Flores and N. Vazquez, respectively, with obtaining specified property constituting and derived from proceeds of drug trafficking, and sought forfeiture of that property pursuant to 21 U.S.C. § 853(a) (1988). Following a jury trial, the appellants were convicted on a variety of counts, all of which (together with the sentences imposed) are summarized in the appendix attached to this opinion. In the course of the litigation, the district court rendered two published opinions; a pretrial opinion, reported at 683 F.Supp. 56 (S.D.N.Y.1988), which denied motions by the Torres brothers and Flores attacking the charges against them under 21 U.S.C. § 848(b) (1988) and seeking a bill of particulars; and a posttrial opinion, reported at 699 F.Supp. 419 (S.D.N.Y.1988), denying motions by the Torres brothers and Flores attacking the constitutionality of the sentence of life imprisonment without parole mandated by section 848(b), and motions by these defendants and D. Rivera, Velez and Coffie for acquittal on one or more counts pursuant to Fed.R.Crim.P. 29(a), or, in the case of Flores and Coffie, a new trial pursuant to Fed.R.Crim.P. 33. The claims on appeal are fully outlined in the discussion that follows. For the reasons set forth therein, we affirm the judgments of conviction, except that (1) we reverse the conviction of Velez on count fourteen for violation of 18 U.S.C. § 924(c)(1) (1988); and (2) we vacate the convictions of the Torres brothers and Flores on counts two through four for violation of 21 U.S.C. § 848(b) (1988), which mandates a sentence of life without parole, and remand for re-sentencing on these counts pursuant to 21 U.S.C. § 848(a) (1988). Background The Torres Organization was a highly organized and extremely profitable heroin operation begun by the Torres brothers early in 1981 in the lower east side of Manhattan. Sometime early in the 1980’s, the Torres brothers moved this operation into the south Bronx and began distributing the “Checkmate” brand of heroin, signified by the sketch of a chess piece — at times, the rook; at other times, the knight — which was stamped on each glas-sine envelope of heroin sold. The Torres Organization purchased bulk quantities of unprocessed heroin, which were taken to a network of processing points, referred to as “mills,” where the bulk quantities of heroin were “cut” or diluted and then packaged in glassine envelopes for street level distribution. Electronic surveillance revealed, for example, that the Torres organization conducted heroin milling operations at at least two locations in May and June of 1987. One was a vacant apartment in the south Bronx that had been rented by Flores. The other was a cooperative apartment in the same area owned by L. Rivera. After the heroin was packaged in the glassine envelopes, the envelopes were repackaged in groups of ten known as “bundles.” These bundles were then picked up by “runners” who delivered them to the managers of various street locations, where the sales were conducted. The proceeds of the sales were then returned to the overseers at the mills by the runners. These transactions were recorded in ledgers. Each street manager was required to provide Flores daily with a slip of paper noting how much heroin had been received that day, how much had been sold, how much money had been deducted for expenses, and how much cash was being remitted with the slip. Flores would then enter the figures in a ledger, and tape the slip of paper over the part of the ledger page containing the entries for that location. Some of these ledgers were seized in the course of arrests and searches on June 24, 1987 that effectively terminated the operations of the Torres Organization. One was found at Flores’ apartment, another was found at Manuel Vazquez’ apartment, and a third was found at 2700 Grand Concourse, an apartment leased by Flores. The three ledgers were primarily in Flores’ handwriting, identical in appearance and format, and consecutive to one another with respect to the time periods covered, a four-month period ending with the defendants’ arrest on June 24, 1987. The expenses reported on the manager’s slips included payroll for “runners,” “pitchers” and “lookouts,” money spent for beepers, guns and bail, and losses arising from arrests, near-arrests (during which heroin was jettisoned) and stickups. Many of the managers' slips included notes regarding operational matters, in addition to the numerical data. For example, one manager assured Flores in a March 29, 1987 slip: “Don’t worry, I will do much better.” Velez wrote to Flores on May 29, 1987, stating: “[Mjaybe today we could have done more if we get it faster.” Elsewhere in the ledgers, there is a note from Velez thanking “Nelson + Crew” for showing interest in a “problem” Velez was encountering; another explaining: “Nelson we had a bad day ... cops all over the place;” and still another stating: “Nelson look yesterday we had a bad day. My pitcher got caught. The other pitcher I put got beat up by the cops so today I had nobody to work until 2:30 p.m. so we’re sorry for the bad day but we’ll get it together.” Similarly, Velez and other street managers sent Flores messages reminding him that he had authorized the taking of a cab, approved the deduction of a particular amount of pay, and delayed another individual’s pay. The Torres Organization proved highly profitable, with the lion’s share of the proceeds going to the Torres brothers. Eventually, they began investing the drug proceeds in homes, and business properties and ventures, in Puerto Rico, including Tower Lanes Plaza, a shopping mall and bowling alley complex in Bayamon, Puerto Rico which opened in the summer of 1986. At about this time, the Torres Brothers relocated to Puerto Rico and Flores took charge, under their supervision, of the day-to-day operations of the Torres Organization in New York. On May 27, 1987, the New York Drug Enforcement Task Force (“NYDETF”) obtained authorization to place a wiretap on Flores’ telephone. The wiretap remained in place for twenty-eight days, during which time more than 2,400 telephone calls were made or attempted. The recorded conversations, many of which were played at trial, provided a detailed picture of the ongoing heroin operation conducted by the Torres Organization. On June 24, 1987, teams of NYDETF agents in New York and Puerto Rico converged upon various locations controlled by the Torres Organization and arrested appellants and others. Simultaneous searches recovered large quantities of heroin, drug ledgers and other records, drug paraphernalia used for the packaging of heroin, numerous weapons, bullet proof vests, lai^ snrnR 0f cosh, iewelrv and beepers. The indictme* an(j superseding indictment hereinabove described were thereafter returned. Tria commenced on April 25, 1988, and the jury ^turned guilty verdicts on most of the count.. 0f the superseding indictment on July 6, 1\88, as detailed in the appendix to this opinion. A separate trial on the forfeiture counts commenced on July 11, 1988 and concluded the next day, when the jury returned verdicts of forfeiture against the Torres brothers, Flores and Vasquez. Sentences were imposed, and judgments of conviction entered, in September and October, 1988. This appeal followed. Further factual matters will be set forth in the discussion of the particular issues to which they relate. Discussion Appellants urge numerous grounds for reversal, and most join in each other’s arguments, to the extent generally applicable, pursuant to Fed.R.App.P. 28(i). We consider: (a) claims of insufficiency of the evidence as to the convictions of Vazquez, Velez, D. Rivera and Cruz for using and carrying a firearm in connection with drug trafficking, the convictions for narcotics conspiracy of D. Rivera, Cruz, Padrón, Ar-celay and Coffie, and the convictions for narcotics possession of D. Rivera and Cruz; (b) the ex post facto challenge of the Torres brothers and Flores to their conviction and mandatory life sentence under 21 U.S.C. § 848(b) (1988); (c) the claim by D. Rivera that his trial should have been severed; (d) Flores’ contention that certain wiretap evidence should have been suppressed; (e) Coffie’s claim that his motion to view the grand jury minutes was improperly denied and that the indictment should have been dismissed as to him (and perhaps all defendants) because of grand jury irregularities; (f) Cruz’ claim that his motion for a bill of particulars was improperly denied; (g) contentions that the trial court improperly (1) admitted evidence that guns seized during the searches had previously been fired, (2) admitted evidence concerning an uncharged homicid’ ® admitted testimony by narcotics e^erts as to meaning of narcotics rela*^ conversations, and (4) excluded excu^01^ evidence offered by Cruz; (h) /aallenges to the trial court’s jury instru'cions concerning (1) the relationship betv¿en subsections (a) and (b) of 21 U.S.C. / 848 (1988), (2) the requirements for a firearm conviction pursuant to 18 U.S.C. § 924(c)(1) (1988), (3) the meaning of reasonable doubt, and (4) the meaning of constructive possession, as well as (5) an attack upon its refusal to charge that a conspirator must have a “stake in the venture”; (i) claims of improprieties in the government’s rebuttal summation; and, finally, (j) claims that the sentences imposed upon the Torres brothers, Flores and Coffie were excessive. The Torres brothers and Flores advance a number of other arguments with respect to their convictions under 21 U.S.C. § 848(b) (1988). They contend that this statute, which mandates life imprisonment without parole for certain drug “kingpins” under specified conditions, is unconstitutional both on its face and as applied to them. They also claim that the proof as to section 848(b)(2)(B), which requires that a continuing criminal enterprise have gross receipts of $10,000,000 during some twelvemonth period, was insufficient. Flores challenges the sufficiency of the proof that he was ever a principal administrator, organizer or leader of the Torres Organization, as required by section 848(b)(1), or in any event that he occupied such a position for a statutorily adequate period of time. Since, as hereinafter appears, we vacate the convictions of the Torres brothers and Flores under section 848(b) and remand for resen-tencing under section 848(a), on the ground that the jury was not instructed that these defendants had to function as principal administrators, organizers or leaders of the Torres Organization after section 848(b) became effective in order to be subjected to its penalties, we do not consider herein the other challenges which these appellants press with respect to their convictions under section 848(b). A. Sufficiency of the Evidence. Before considering specific claims as to the sufficiency of the evidence, we review the general standards by which these contentions are to be assessed. An appellant challenging the sufficiency of the evidence bears “ ‘a very heavy burden.’ ” United States v. Nusraty, 867 F.2d 759, 762 (2d Cir.1989) (quoting United States v. Young, 745 F.2d 733, 762 (2d Cir.1984), cert. denied, 470 U.S. 1084, 105 S.Ct. 1842, 85 L.Ed.2d 142 (1985) (quoting United States v. Carson, 702 F.2d 351, 361 (2d Cir.), cert. denied, 462 U.S. 1108, 103 S.Ct. 2456, 2457, 77 L.Ed.2d 1335 (1983))); see United States v. Buck, 804 F.2d 239, 242 (2d Cir.1986); United States v. Grubczak, 793 F.2d 458, 462-63 (2d Cir.1986). In reviewing such claims, we “view the evidence in the light most favorable to the government and construe all possible inferences in its favor....” United States v. Badalamenti, 794 F.2d 821, 828 (2d Cir.1986) (citing United States v. Martino, 759 F.2d 998, 1002 (2d Cir.1985)). “If ‘any rational trier of fact could have found the essential elements of the crime,’ the conviction must stand.” Badalamenti, 794 F.2d at 828 (quoting Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 2789, 61 L.Ed.2d 560 (1979) (emphasis in Jackson)). “The test is ‘whether the jury, drawing reasonable inferences from the evidence, may fairly and logically have concluded that the defendant was guilty beyond a reasonable doubt.’ ” United States v. Chang An-Lo, 851 F.2d 547, 554 (2d Cir.) (quoting Grubczak, 793 F.2d at 463), cert. denied, — U.S. -, 109 S.Ct. 493, 102 L.Ed.2d 530 (1988). The government is not required to “preclude every reasonable hypothesis which is consistent with innocence.” Chang An-Lo, 851 F.2d at 554 (citing United States v. Fiore, 821 F.2d 127, 128 (2d Cir.1987)). In sum, “[a] jury’s verdict will be sustained if there is substantial evidence, taking the view most favorable to the government, to support it.” United States v. Nersesian, 824 F.2d 1294, 1324 (2d Cir.1987) (citing Glasser v. United States, 315 U.S. 60, 80, 62 S.Ct. 457, 469, 86 L.Ed. 680 (1942)), cert. denied, 484 U.S. 957, 958, 108 S.Ct. 355, 357, 98 L.Ed.2d 380, 382 (1987), 484 U.S. 1061, 108 S.Ct. 1018, 98 L.Ed.2d 983 (1988). We now turn to appellants’ specific claims of insufficiency. 1. Natalie Vazquez. While searching an apartment in the Bronx leased by N. Vazquez and apparently shared with a male occupant, agents found a loaded .357 Magnum hand gun under a queen size mattress. The apartment also contained two bundles of heroin, two bulletproof vests, $209,485 in cash, jewelry appraised at $105,695, a $10,000 gold ingot, drug records, rubber stamps and stamp pads, a heat sealer, and several address books containing the telephone numbers of various other members of the Torres Organization. The apartment was also tied to the Torres Organization through a recorded telephone conversation which indicated that a package of heroin was to be dropped off there. On this evidence, N. Vazquez was convicted under 18 U.S.C. § 924(c)(1) (1988), which provides criminal penalties for anyone who “during and in relation to any ... drug trafficking crime ..., uses or carries a firearm....” On appeal, Vazquez claims that the circumstances linking the .357 Magnum to the narcotics activity were too tenuous to sustain a conviction under section 924(c)(1), especially in light of United States v. Feliz-Cordero, 859 F.2d 250 (2d Cir.1988), a case in which a section 924(c)(1) conviction was reversed because of insufficiency of the supporting evidence. Specifically, N. Vazquez claims that (1) since there was another, male occupant of the apartment, and especially since the firearm had “a strong recoil and a heavy pull-weight” rendering it more appropriate for use by a man, “the inference of possession which normally arises when an apartment is inhabited by one person does not apply;” (2) the evidence established that two men were required to lift the mattress which concealed the gun, precluding any implication that the weapon was readily available to N. Vazquez; (3) there was no evidence that the apartment functioned as a storage location for narcotics on an ongoing basis; and (4) there was no evidence that N. Vazquez ever carried a weapon, or that weapons were kept in the apartment at any time other than the date of the search. All of these circumstances, N. Vazquez claims, provide an even more favorable basis than in Feliz-Cordero for finding, as a matter of law, that the evidence was insufficient. We conclude, on the contrary, that our decisions in United States v. Alvarado, 882 F.2d 645 (2d Cir.1989), cert. denied, — U.S.-, 110 S.Ct. 1114, 107 L.Ed.2d 1021 (1990), and United States v. Meggett, 875 F.2d 24 (2d Cir.), cert. denied, — U.S. -, 110 S.Ct. 166, 107 L.Ed.2d 123 (1989), call for affirmance of N. Vazquez’ conviction under section 924(c)(1). See also United States v. Matra, 841 F.2d 837 (8th Cir.1988). In Meggett, we interpreted Feliz-Cordero as holding: that a gun found in a dresser drawer of an apartment in which some of the defendants’ narcotics paraphernalia was located had not been “used” within the meaning of § 924(c)(1). Implicitly recognizing the teaching of the prior case law to the effect that “use” requires possession of a gun under circumstances where the weapon is so placed as to be an integral part of the offense, we emphasized the absence of proof that the defendants in Feliz-Cordero had placed the weapon to have it available for ready use during the transaction. Meggett, 875 F.2d at 29 (citation omitted). Our holding in Meggett made clear, after a detailed review of the pertinent precedents, that a defendant can “use” a gun in violation of section 924(c)(1) “without firing, brandishing or displaying it.” Meggett, 875 F.2d at 29; see, e.g., United States v. Robinson, 857 F.2d 1006, 1010 (5th Cir.1988). In Meggett, we determined that the jury “could reasonably conclude that the five loaded firearms in [defendant’s] apartment were on hand to protect that apartment as a storage and processing point for large quantities of narcotics and that therefore the presence of weapons furthered or facilitated the narcotics operation and was an integral part thereof.” 875 F.2d at 29. Our more recent decision in Alvarado is also pertinent, especially in view of N. Vazquez’ contention concerning the inaccessibility of the .357 Magnum stored under the mattress. In a somewhat similar situation, we said in Alvarado that “[although it is true that these guns were placed in a locked safe, a reasonable jury could infer that the guns were located there to protect both the money and the cocaine in the event that a drug deal went sour and a buyer demanded a return of his cash.” 882 F.2d at 654. In Matra, the Eighth Circuit upheld a section 924(c)(1) conviction, finding that a machine gun hidden under a waterbed frame in a locked bedroom was “an integral part of [the] criminal undertaking” because it served to protect the cocaine and cash stored in the apartment. 841 F.2d at 842-43. No different conclusion is required here. The jury was certainly entitled to conclude, in view of the overall physical evidence seized at the N. Vazquez apartment and the recorded telephone conversation regarding a delivery of heroin there, that the apartment was used for narcotics trafficking on a continuing basis, bolstering the likelihood that the weapon seized was used “during and in relation to any ... drug trafficking crime” within the meaning of section 924(c)(1). Testimony that two men were required to lift the mattress which concealed the gun did not preclude the jury from finding that the gun would be available to a person who knew its location, without any need to lift the mattress. Further, there was explicit testimony that a woman would be able to fire the weapon. In any event, we see no merit in N. Vazquez’ novel contention that, in effect, a defendant cannot be convicted under section 924(c)(1) if it is likely that a cohort in a narcotics crime, rather than the defendant, will use a particular firearm to further their joint criminal enterprise. Cf. United States v. Rivera, 844 F.2d 916, 926 (2d Cir.1988) (not necessary that exercise of dominion and control by others be disproved; only necessary that evidence support jury finding that defendant exercised dominion and control over weapon). In sum, we conclude that the evidence amply supported N. Vazquez’ conviction under section 924(c). 2. Reginald Velez. Velez was also convicted of using a firearm in relation to a narcotics trafficking offense in violation of section 924(c)(1). The evidence to support this charge consisted of a slip itemizing receipts and expenses given by Velez to Flores on or about June 17, 1987, one of many submitted by Velez to Flores over the four-month period covered by the seized ledgers, and a corresponding ledger entry by Flores. The slip showed a $150 expenditure for a shotgun with the added notations: “Bought a shotgun for our protection,” and “we had to buy a gun because there [are] a lot of things happ[en]ing so we want to feel safe.” Flores entered the deduction in his ledger as follows: “Shotgun — 150.” However, the shotgun was not seized or presented as evidence. On appeal, Velez claims that this evidence was insufficient to support his conviction (1) where no shotgun was recovered or seen by any witness, (2) because the conviction was based on his uncorroborated admission, and (3) because there was no evidence that he used the weapon for the stated purpose. We agree with Velez’ third contention, that the slip and ledger entry fail to establish that the shotgun was used “during and in relation to any ... drug trafficking crime” within the meaning of section 924(c)(1), and accordingly reverse his conviction on the firearm count without considering his other grounds for reversal. We stated in Meggett that statutory use “requires possession of a gun under circumstances where the weapon is so placed as to be an integral part of the offense,” 875 F.2d at 29 (construing Feliz-Cordero), noting that the reversal of the firearm conviction in Feliz-Cordero resulted from “the absence of proof that the defendants ... had placed the weapon to have it available for ready use during the transaction,” id., even though the weapon in Feliz-Cordero was found together with drug paraphernalia in a defendant’s apartment. Here, by contrast, assuming that Velez did purchase the shotgun as reflected by the slip and ledger entry, and assuming further that he intended to use it as stated — “for our protection,” it nonetheless remained to be proved that it was actually so used. There was no evidence as to where the shotgun was placed, and no evidence that the shotgun was ever in fact utilized to protect the narcotics operation or its proceeds. Under these circumstances, both the statutory language and our precedents require the reversal of Velez’ conviction under section 924(c)(1). 3. Dennis Rivera. D. Rivera was convicted on count one, the narcotics conspiracy count, count thirteen for possession of cocaine with intent to distribute it, and count seventeen for a section 924(c)(1) firearm violation. Although he sought acquittal in a posttrial motion pursuant to Fed.R.Crim.P. 29(c) and renews his request for acquittal here, his appellate arguments are directed solely to the convictions on counts thirteen and seventeen. Specifically, he contends that there was an inadequate nexus between him and items of contraband, a quantity of cocaine and a hand gun, seized by the government on June 24, 1987 at 527 East 147th Street in the Bronx. We disagree. The nexus was amply established. At trial, the government showed through a number of taped conversations that D. Rivera conducted a narcotics business from that address, which was the situs of a four-story apartment building. According to the testimony of NY-DETF agents, the raid on that date on apartment no. 7 in that building yielded a pistol holster; car rental receipts in the names of Flores and Arcelay; two social security cards bearing D. Rivera’s printed name and signature; and a scrap of paper with Flores’ telephone number. A search of apartment no. 6, one floor beneath apartment no. 7, was conducted simultaneously. Three individuals were found there, ..including D. Rivera. The agents also found boxes of glassine envelopes; beepers; a business card bearing Nelson Flores’ beeper number and another telephone number next to the word “Nison [sic]” on the reverse side of the card; and approximately $52,160 worth of jewelry. In the kitchen, agents noticed that a door leading to a dumbwaiter shaft was ajar. There was a ladder inside the shaft that began at apartment no. 6 and descended into the shaft. There was also a string hanging down into the shaft from the doorway in the kitchen of apartment no. 6. On a ledge inside the shaft, one floor below apartment no. 6, an investigating agent found 75.5 grams of 92% pure cocaine and a triple-beam O-haus scale. He also found $5,942 in cash and a loaded .38 caliber revolver attached to the string at the bottom of the shaft. According to the agents, all of the shaft doors that led to the other apartments were either painted shut or otherwise sealed, so that there was access to the shaft only from apartment no. 6. Considering the evidence provided by the taped conversations that D. Rivera conducted a narcotics operation at this location; the other items seized during the search; and D. Rivera’s apprehension in apartment no. 6 at the time of the search, “the evidence showed far more than [D. Rivera’s] mere proximity to the [contraband] and provided an ample basis for a reasonable juror to find that [he] had constructive possession of the [contraband].” United States v. Tribunella, 749 F.2d 104, 112 (2d Cir.1984). “ ‘It is not necessary that such evidence remove every reasonable hypothesis except that of guilt.’ ” Id. (quoting United States v. Craven, 478 F.2d 1329, 1333 (6th Cir.), cert. denied, 414 U.S. 866, 94 S.Ct. 54, 38 L.Ed.2d 85 (1973)). We find no basis to disturb D. Rivera’s conviction on counts thirteen and seventeen. 4. Pedro Cruz. Cruz claims that the evidence was insufficient to convict him on count one for narcotics conspiracy, count seven for possession of heroin with intent to distribute it, and count fifteen for a section 924(c)(1) firearm violation. Since Cruz challenges his conviction under count one for narcotics conspiracy, and all the remaining appellants whose insufficiency claims we must consider contest only their convictions under this count, it is appropriate at this juncture to consider the general principles governing sufficiency of the evidence to sustain conspiracy convictions. Since “conspiracy by its very nature is a secretive operation,” United States v. Provenzano, 615 F.2d 37, 45 (2d Cir.), cert. denied, 446 U.S. 953, 100 S.Ct. 2921, 64 L.Ed.2d 810 (1980), the “ ‘[existence of and participation in a conspiracy ... may be established ... through circumstantial evidence.’ ” United States v. Soto, 716 F.2d 989, 991 (2d Cir.1983) (quoting United States v. Sanzo, 673 F.2d 64, 69 (2d Cir.), cert. denied, 459 U.S. 858, 103 S.Ct. 128, 74 L.Ed.2d 111 (1982)). However, “knowledge of the existence and goals of a conspiracy does not of itself make one a coconspirator.” United States v. Cianchetti, 315 F.2d 584, 588 (2d Cir.1963). Similarly, “[association with a conspirator, without more, is insufficient to establish the requisite degree of participation in a conspiratorial venture.... ” United States v. Steinberg, 525 F.2d 1126, 1134 (2d Cir.1975), cert. denied, 425 U.S. 971, 96 S.Ct. 2167, 48 L.Ed.2d 794 (1976); see also United States v. Johnson, 513 F.2d 819, 824 (2d Cir.1975) (“[gjuilt may not be inferred from mere association with a guilty party”). Moreover, “ ‘absent evidence of purposeful behavior, mere presence at the scene of a crime, even when coupled with knowledge that a crime is being committed, is insufficient to establish membership in a conspiracy....’ ” United States v. Chang An-Lo, 851 F.2d 547, 554 (2d Cir.) (quoting United States v. Martino, 759 F.2d 998, 1002 (2d Cir.1985)), cert. denied, — U.S. -, 109 S.Ct. 493, 102 L.Ed.2d 530 (1988). Thus, evidence of purposeful behavior designed to further a conspiracy must be shown to prove membership in that conspiracy. See United States v. Torres, 519 F.2d 723, 726 (2d Cir.), cert. denied, 423 U.S. 1019, 96 S.Ct. 457, 46 L.Ed.2d 392 (1975). However, “once a conspiracy is shown to exist, the evidence sufficient to link another defendant to it need not be overwhelming.” United States v. Casamento, 887 F.2d 1141, 1156 (2d Cir.1989), cert. denied, — U.S. ——, 110 S.Ct. 1138, 107 L.Ed.2d 1043 (1990). We now turn to the specifics of Cruz’ insufficiency claim. Cruz was arrested on June 24, 1987 when a team of NY-DETF agents gained access to an apartment at 2700 Grand Concourse through the use of a battering ram. Agents then entered one of the back bedrooms of the apartment, where they encountered six individuals, four of whom were emptying a duffel bag filled with glassine envelopes out a window. The duffel bag was then flung from the window and was recovered by a NYDETF agent stationed in the courtyard below. The bag contained approximately 6,150 glassine envelopes of heroin packaged in “bundles” of ten and weighing a total of approximately 215 grams. An agent also testified that when he entered the room, Cruz was lunging for a loaded nine millimeter semi-automatic weapon lying on a table in the room, but was intercepted by the agent before he reached the gun. In addition to the testimony of the arresting officers, the Government presented other evidence linking Cruz with the Torres Organization, including the testimony of agents who surveilled Cruz coming and going from several locations controlled by the Torres Organization, often with packages in hand. In addition, several accounting slips sent to Flores by Velez made reference to a runner named “Pete,” which was Cruz’ nickname. Further, the government presented a taped conversation between Cruz and Flores in which they discussed the operation of one of the Torres Organization’s sales locations. Despite this evidence, Cruz disavows any involvement in the conspiracy, and contends that his presence in the apartment on the day of his arrest was simply a chance presence in an “environment of criminality,” where he was wearing a matching cabana set and asserts that he had made a brief stop en route to an outing at the beach. Cruz also contends that since he was not seen in physical contact with the heroin jettisoned from the window, he cannot be charged with its possession, and further that the act of lunging for the weapon does not meet the requirement of section 924(c)(1) that “during and in relation to any crime of ... drug trafficking ..., [he] use[ ] or carr[y] a firearm.” We conclude, however, that the evidence was sufficient to convict Cruz on all counts. The government’s wiretap evidence, the appearance of Cruz’ name on the accounting slips, and his presence in the apartment at the time of the raid provided ample evidence for the jury to conclude that he was part of the charged conspiracy. Cruz’ conviction on count seven, for possession of heroin with intent to distribute it, was also supported by the evidence. There is no requirement that a defendant be observed in physical contact with narcotics in order to be convicted of its possession. Rather, possession of narcotics may be actual or constructive. See United States v. Aiello, 864 F.2d 257, 263 (2d Cir.1988); United States v. Tribunella, 749 F.2d 104, 111 (2nd Cir.1984). “‘Constructive possession exists when a person ... knowingly has the power and the intention at a given time to exercise dominion and control over an object, either directly or through others.’ ” United States v. Pelusio, 725 F.2d 161, 167 (2d Cir.1983) (quoting United States v. Craven, 478 F.2d 1329, 1333 (6th Cir.), cert. denied, 414 U.S. 866, 94 S.Ct. 54, 38 L.Ed.2d 85 (1973)). On the facts presented, it was quite reasonable for the jury to have concluded that the heroin jettisoned from the window of the apartment by Cruz’ codefendants was within the constructive possession of Cruz. Finally, Cruz claims with regard to count fifteen that his thwarted effort to reach the semi-automatic weapon when the NYDETF agents entered the apartment does not constitute the “use” of that firearm within the meaning of section 924(c)(1). As discussed above, however, section 924(c)(1) has been applied in numerous situations where firearms were simply kept available in locations where narcotics activities took place. See e.g., United States v. Alvarado, 882 F.2d 645, 654 (2d Cir.1989), cert. denied, — U.S.-, 110 S.Ct. 1114, 107 L.Ed.2d 1021 (1990); United States v. Meggett, 875 F.2d 24, 29 (2d Cir.), cert. denied, — U.S. -, 110 S.Ct. 166, 107 L.Ed.2d 123 (1989); United States v. Robinson, 857 F.2d 1006, 1010 (5th Cir.1988); United States v. Matra, 841 F.2d 837, 842 (8th Cir.1988). A fortiori, Cruz’ barely thwarted effort to utilize a firearm so located against the NYDETF agents violates the statute. In view of the evidence, furthermore, that the agents announced their presence before battering down the door to the apartment, and that the agent who entered the room was wearing a bulletproof vest with “DEA” written across it and had a gold police shield on a chain around his neck, the jury was surely entitled to conclude that Cruz was attempting to use the firearm knowingly against law enforcement officers. 5. Fernando Padrón. Padrón claims that the evidence presented was insufficient to support his conviction under count one for narcotics conspiracy. While conceding his knowledge of the existence and goals of the conspiracy, Padrón claims that his membership in the conspiracy was improperly presumed because of his association with his roommate, an individual named “Jimmy,” who, Padrón contends, was the manager of one of the organization’s sales locations. We disagree. The government contended that Padrón comanaged one of the heroin sales locations with his roommate Jimmy. One of the intercepted conversations played for the jury contained the following exchange between Padrón and Flores regarding that location: FLORES: (UI), uh, why didn’t you people send money today? PADRON: Because we, we were in the, uh ... because we’re (UI) here. He beeped and (UI) to beep ... waiting to (UI) that you had left already. That’s why we didn’t send it. We had it upstairs. Flores: Okay, uh ... okay. I’m gonna —you’11 be sent goods tomorrow. But you guys have to — one thing — you guys have to send everyday ... You guys have to improve the spot, and you have to send every day, okay? Padrón: But if — look, Nelson, let me give you some details. The spot was improving. We were sending you (UI) day everything that ... everything (UI). Does (UI) think that we don’t pay ... don’t pay? Everything we sent was (UI) ... Flores: And it has to be (UI) everyday. See they are complaining that, that ... Padrón: That’s why we wanted that a higher amount of material be sent, to make a little — only one payment for the amount of material because this way we ... [stutters] ... (UI) Flores: Yeah, but since you didn’t send, didn’t (UI) ... they’re not — Anyway, that’s fine, forget it. We’ll ... open for you tomorrow. Padrón: Early? Flores: Early. Beep ... beep me. If they don’t bring anything over to you in an hour, beep me. I’ll get it for you myself. Padrón: That’s fine. There was testimony at trial that Padrón acknowledged, at the time of his arrest and after receiving Miranda warnings, his participation in the quoted conversation. Pa-drón was also mentioned by Flores in another conversation with Cruz regarding the closing of the heroin sales location. In that conversation Flores was heard to say “Did you ... by any chance tell Jimmy or Fernando that we were closing them down.” Additionally, the jury was presented with drug ledgers containing notations for “Nando.” Based upon this evidence, the jury was justified in concluding that Padrón participated in the conspiracy. 6. Efrain Arcelay. Arcelay also contends that the evidence was insufficient to convict him under count one for narcotics conspiracy. He acknowledges that he was the roommate and a close friend of Flores during the period covered by the investigation, and also admits to having been a cocaine dealer. Arcelay claims, however, that the government failed to establish that he was involved in the heroin conspiracy charged, because he lacked the “specific intent” to advance the conspiracy to sell heroin, but rather acted solely as a roommate and friend of Flores. In support of this claim, Arcelay refers to conversations intercepted by the government between Arcelay and Flores in which Flores assured Arcelay that Arcelay was not under police surveillance. Arcelay contends that Flores knew or suspected that Flores was then under surveillance, and that Flores’ lack of concern over surveillance of Arcelay is consistent with Arce-lay’s claim that Flores did not consider Arcelay a part of the heroin conspiracy. Arcelay also points out that several of the rolodexes seized by the police which listed many members of the Torres Organization did not include Arcelay’s name, giving further credence to his claim that he was not a member of the conspiracy. On the other hand, the government contends that Arcelay, who had a full-time job at a local hospital, “while not a full-time employee of the Torres organization, was nonetheless allied with the Torres organization and could be counted on to assist it when needed.” At trial, the government established that Arcelay allowed V. Torres to purchase and register a car in Arcelay’s name, and that this ear was used to transport drug proceeds by the Torres Organization. On another occasion, Arcelay allowed Flores to use his name as a reference when Flores purchased a car and when he opened a safe deposit box. On still another occasion, Arcelay cancelled a lease and returned a key to a landlord for an apartment in Queens used by the Torres Organization. Finally, the government also presented evidence that Arcelay frequently relayed messages for Flores to other members of the Organization, and on one occasion assisted Flores in locating a worker for a special assignment. In view of Arcelay’s conceded knowledge of the existence, purpose and operations of the conspiracy, the foregoing evidence sufficed to establish “demonstrated awareness of [the] conspiracy’s existence coupled with his active participation.” United States v. Torres, 519 F.2d 723, 726 (2d Cir.), cert. denied, 423 U.S. 1019, 96 S.Ct. 457, 46 L.Ed.2d 392 (1975). As the government correctly contends, once this was shown, Arcelay’s claim that his participation was motivated by friendship with Flores is irrelevant to the question of Arcelay’s criminal liability. See United States v. Bagaric, 706 F.2d 42, 53 (2d Cir.), cert. denied, 464 U.S. 840, 917, 104 S.Ct. 133, 134, 283, 78 L.Ed.2d 128, 261 (1983). 7. Raymond E. Coffie. Coffie owned a small construction business in the Bronx. He rented beepers to the Torres Organization over a two-year period, and supplied members of the Organization with false income documents such as a paycheck, earning statements, and wage and tax statements. In addition, on one occasion he supplied and delivered an air conditioning unit to one of the locations where heroin was processed. The ledgers of the Torres Organization reflect more than $200,000 in payments to Coffie. He was a participant in a number of intercepted telephone conversations with Flores, in one of which Coffie made reference to a recent telephone conversation he had had with “Victor.” While conceding that “much evidence was offered by the Government to show that ... Coffie freely associated with members of the conspiracy and that some actions he took actually aided the conspiracy,” Coffie claims “that a careful analysis of the proof against him will demonstrate, amply, that the jury did not have sufficient proof before it to find that he knew of the conspiracy or that he willfully associated himself with it.” Rather, Coffie contends that the prosecution failed to establish the element of guilty knowledge “that would otherwise transform his routine business activities, such as renting beepers and selling air-conditioners, from unremarkable commerce into the intentional furtherance of a heroin conspiracy.” We disagree. In United States v. Zambrano, 776 F.2d 1091 (2d Cir.1985), we said: [EJvidence that a defendant simply supplies goods, innocent in themselves, to someone who intended to use them illegally is not enough to support a conviction for conspiracy. But, if there is something more, some indication that the defendant knew of and intended to further the illegal venture, that he somehow encouraged the illegal use of the goods or had a stake in such use, sufficient evidence has been presented to enable the jury to conclude the defendant had knowledge of and an intent to join in the conspiracy.... Id. at 1095 (emphasis added); cf. United States v. Rush, 666 F.2d 10, 11-12 (2d Cir.1981) (loaning money for purchase of marijuana “at an exorbitant and usurious profit ... through a clandestine method” sufficient to convict for conspiracy; defendant conceded knowledge of illegal use of loan proceeds); United States v. Piampiano, 271 F.2d 273 (2d Cir.1959) (vegetable dealer supplying sugar to illegal distillery convicted of conspiracy; knowledge implied from circumstances, including departure from normal business and secretive mode of transacting sugar business). There was clearly “something more” in this case. The jury could properly infer that in supplying false income documents to members of the Torres Organization, Coffie was aware that they required this assistance because they were not engaged in legitimate activities which would routinely provide them with such documents. More to the point, a number of the taped telephone conversations were more than sufficient to warrant a jury conclusion that Coffie knew the business in which the Torres Organization was engaged. When arranging with Coffie to install an air conditioner at one of the heroin processing locations, for example, Flores told Coffie that the installation would have to take place “late at night or before they start,” to which Coffie replied “no problem.” On another occasion, Flores and Coffie engaged in an extensive discussion of beeper malfunctions from which the jury was entitled to infer that Coffie knew the use to which the beepers were being put. In sum, as the district court concluded, “While there may be no ‘smoking gun’ heroin transaction linking Coffie to the conspiracy, there is a wealth of circumstantial evidence that, when viewed together, supports the jury’s conclusion and is sufficient as a matter of law to sustain the conviction.” United States v. Torres, 699 F.Supp. 419, 426 (S.D.N.Y.1988). B. Convictions of the Torres Brothers and Flores under 21 U.S.C. § 848(b). The Torres brothers and Flores challenge the application of the “super kingpin” statute, 21 U.S.C. § 848(b) (1988), pursuant to which all three were sentenced to life imprisonment without parole. Section 848(a) 'permits the imposition of a life sentence upon a defendant convicted of its violation. Section 848(b) requires the imposition of a life sentence upon a defendant convicted under Section 848(a) if, in addition, the requirements of subsection (b) are satisfied. Section 848(e) precludes the suspension of, or grant of probation with respect to, any sentence imposed under section 848. As stated at the outset of this Discussion, because we agree with these appellants that the jury should have been instructed that the Torres brothers and Flores had to function as principal administrators, organizers or leaders of the Torres Organization after section 848(b) became effective, and therefore vacate their convictions thereunder and remand for resentencing under section 848(a), we do not consider herein their other challenges to their convictions under section 848(b). Section 848, as applicable here, see supra note 3, read as follows: Continuing criminal enterprise (a) Penalties; forfeitures Any person who engages in a continuing criminal enterprise shall be sentenced to a term of imprisonment which may not be less than 10 years and which may be up to life imprisonment, to a fine not to exceed the greater of that authorized in accordance with the provisions of title 18, or $2,000,000 if the defendant is an individual or $5,000,000 if the defendant is other than an individual, and to the forfeiture prescribed in section 853 of this title; except that if any person engages in such activity after one or more prior convictions of him under this section have become final, he shall be sentenced to a term of imprisonment which may not be less than 20 years and which may be up to life imprisonment, to a fine not to exceed the greater of twice the amount authorized in accordance with the provisions of title 18, or $4,000,000 if the defendant is an individual or $10,000,000 if the defendant is other than an individual, and to the forfeiture prescribed in section 853 of this title. (b) Life imprisonment for engaging in continuing criminal enterprise Any person who engages in a continuing criminal enterprise shall be imprisoned for life and fined in accordance with subsection (a) of this section, if— (1) such person is the principal administrator, organizer, or leader of the enterprise or is one of several such principal administrators, organizers, or leaders; and (2)(A) the violation referred to in subsection (d)(1) of this section involved at least 300 times the quantity of a substance described in subsection 841(b)(1)(B) of this title, or (B) the enterprise, or any other enterprise in which the defendant was the principal or one of several principal administrators, organizers, or leaders, received $10 million dollars in gross receipts during any twelve-month period of its existence for the manufacture, importation, or distribution of a substance described in section 841(b)(1)(B) of this title. (d) “Continuing criminal enterprise” defined For purposes of subsection (a) of this section, a person is engaged in a continuing criminal enterprise if— (1) he violates any provision of this subchapter or subchapter II of this chapter the punishment for which is a felony, and (2) such violation is a part of a continuing series of violations of this sub-chapter or subchapter II of this chapter— (A) which are undertaken by such person in concert with five or more other persons with respect to whom such person occupies a position of organizer, a supervisory position, or any other position of management, and (B) from which such person obtains substantial income or resources. (e) Suspension of sentence and probation prohibited In the case of any sentence imposed under this section, imposition or execution of such sentence shall not be suspended, probation shall not be granted, and the Act of July 15, 1932 (D.C.Code, secs. 24-203 to 24-207), shall not apply. Section 848(b) was added by the Anti-Drug Abuse Act of 1986, Pub.L. No. 99-570, § 1253, 100 Stat. 3207, and became effective upon the President’s approval of that statute on October 27, 1986. The district court originally addressed the “ex post facto” questions posed by the October 27, 1986 effective date of section 848(b) in its pretrial opinion, stating: Defendants claim that their indictment under § 848(b) also violates the Ex Post Facto clause of the Constitution, since the continuing criminal enterprise alleged in the indictment began before October 27, 1986, the effective date of § 848(b). For the reasons stated below, the Court denies this motion. Defendants in their brief fail to discuss the clear and consistent holdings of many courts that in the ease of continuing offenses, such as the operation of a continuing criminal enterprise, the Ex Post Facto clause is not violated by application of a statute to an enterprise that began prior to, but continued after, the effective date of that statute. United States v. Johnson, 537 F.2d 1170, 1175 (4th Cir.1976); United States v. Ferrara, 458 F.2d 868, 874 (2d Cir.), cert. denied, 408 U.S. 931, 92 S.Ct. 2498, 33 L.Ed.2d 343 (1972). Since the indictment alleges the continuation of a criminal enterprise beyond the effective date of § 848(b), the Court denies this motion. The Court reserves decision on whether income received by the alleged drug enterprise prior to the effective date of the statute may be used to satisfy the requirements of § 848(b)(2)(B). By necessity, the resolution of this issue must await the government’s proof at trial and may be handled with in [sic] an appropriate instruction to the jury. United States v. Torres, 683 F.Supp. 56, 62 (S.D.N.Y.1988) (footnote omitted). In their subsequent request to charge, appellants sought the following instruction: [E]ven if you find that the enterprise grossed $10 million in receipts during a 12-month period and that a defendant was a principal administrator, organizer or leader of that enterprise, this $10 million allegation has not been proven unless you further find that the defendant you are considering was a principal administrator, organizer, or leader of the enterprise during the entire period that it took to gross the $10 million. You may not consider the $10 million allegation proven if you find that the defendant was a “principal administrator, organizer or leader” for any period of time less than that which it took to gross $10 million. Thus, if the defendant joined the enterprise as a principal administrator, organizer or leader during the twelve month period at issue, you may not find this allegation proven as to that defendant. Also, if the defendant was associated with the enterprise in some subordinate capacity part of the time that the $10 million dollars was being grossed and then eventually assumed the rank of principal administrator, organizer or leader, you may not find this allegation proven as to that defendant. In addition, you are not entitled to take into consideration any monies received by the enterprise prior to October 27, 1986. Rather, you must focus on a single 12 month period beginning after that date. Consequently, if you find that the enterprise only received $10,000,000 throughout the course of its entire existence rather than within a specific 12 month period which began after October 27, 1986, then you must find this element not proven. Emphasis partially added. Flores’ counsel reiterated in the charging conference the position that “for Mr. Flores to be found guilty under 848(b) he has to have been a principal ... administrator, organizer or leader for the entire time it took the enterprise to earn the ten million dollars.” The district court rejected this request, and charged: The second of these additional allegations is that the enterprise described in Counts Two through Four earned at least $10 million in gross receipts from the sale of heroin during a one-year period of its existence — specifically, the one year period from, June 24, 1986 to June 23, 1987, that immediately preceded the arrest of the defendants on June 24, 1987. For this element to be satisfied, the government must have also proven beyond a reasonable doubt that the defendant you are considering was a principal administrator, organizer or leader of that enterprise sometime during the 12-month period that the enterprise received at least $10 million in gross receipts. Emphasis added. In addition, the verdict forms provided to the jury included the following questions with respect to the application of section 848(b) to the Torres brothers and Flores: If your verdict on [the count charging the particular defendant with a violation of section 848(a)] is Guilty, answer the following question: 1. Was [the particular defendant] a principal administrator, organizer or leader of the continuing criminal enterprise at some time during the one-year period from June 24, 1986 to June 23, 1987? If your answer to Question One is Yes, answer- the following question: 2. Did the continuing criminal enterprise earn at least $10 million in gross receipts during the one-year period from June 24, 1986 to June 23, 1987 ? Emphasis added. Clearly, both the instruction to the jury and the verdict form answered the question posed in the district court’s pretrial opinion by allowing evidence of receipts prior to October 27, 1986 to be included in the ten million dollar calculation of gross receipts under section 848(b)(2)(B). Whatever the merits of this determination, we regard as dispositive the fact that both the instruction and the verdict form allowed the application of section 848(b)(1) to the Torres brothers and Flores if they were principal administrators, organizers or leaders of the Organization “sometime during the 12-month period [from June 24, 1986 to June 23, 1987],” in the language of the instruction, or “at some time during the one-year period from June 24, 1986 to June 23, 1987,” as the verdict form stated the question. The district court correctly stated in its pretrial opinion that “in the case of continuing offenses, such as the operation of a continuing criminal enterprise, the Ex Post Facto clause is not violated by application of a statute to an enterprise that began prior to, but continued after, the effective date of [section 848(b) ].” United States v. Torres, 683 F.Supp. at 62 (citing United States v. Johnson, 537 F.2d 1170, 1175 (4th Cir.1976); United States v. Ferrara, 458 F.2d 868, 874 (2d Cir.), cert. denied, 408 U.S. 931, 92 S.Ct. 2498, 33 L.Ed.2d 343 (1972)). Further, “[i]t is well established that a statute increasing a penalty with respect to a criminal conspiracy which commenced prior to, but was continued beyond the effective date of the statute, is not ex post facto as to that crime.” United States v. Campanale, 518 F.2d 352, 365 (9th Cir.1975), cert. denied, 423 U.S. 1050, 96 S.Ct. 777, 46 L.Ed.2d 638 (1976). The problem presented here, however, is that both the pertinent instruction and the verdict form allowed the Torres brothers and Flores to be subjected to the enhanced, mandatory life sentence imposed by section 848(b) if they acted as principal administrators, organizers or leaders of the Organization at any time between June 24, 1986 and June 23, 1987, although section 848(b) did not become effective until October 27, 1986. Accordingly, the instruction and verdict form permitted the application of section 848(b) to these defendants even if they did not engage in the specified conduct at any time after that section’s enactment. This is impermissible, in our view, because such an application of section 848(b) would “ ‘make[ ] more onerous the punishment for crimes committed before its enactment.’ ” Miller v. Florida, 482 U.S. 423, 435, 107 S.Ct. 2446, 2454, 96 L.Ed.2d 351 (1987) (quoting Weaver v. Graham, 450 U.S. 24, 36, 101 S.Ct. 960, 968, 67 L.Ed.2d 17 (1981)). Congress is barred from enacting legislation which imposes such a result by the ex post facto clause of U.S. Const, art. I, § 9, cl. 3, and states are so barred by the ex post facto clause of id. art. I, § 10, cl. 1. Since “ ‘the principle on which the [ex post facto] clause is based — the notion that persons have a right to fair warning of that conduct which will give rise to criminal penalties — is fundamental to our concept of constitutional liberty,’ ” United States v. Brown, 555 F.2d 407, 419 (5th Cir.1977) (quoting Marks v. United States, 430 U.S. 188, 191, 97 S.Ct. 990, 992, 51 L.Ed.2d 260 (1977)), cert. denied, 435 U.S. 904, 98 S.Ct. 1448, 55 L.Ed.2d 494 (1978), courts are similarly constrained by the due process clauses of the fifth and fourteenth amendments, id. The government does not contest these settled principles. Rather, it contends that (1) appellants failed to object to the challenged instruction (and consistent verdict form), “stating distinctly the matter to which [they objected] and the grounds of the objection” as required by Fed.R. Crim.P. 30, with the result that (2) we may reverse only if that instruction constituted plain error, see Fed.R.Crim.P. 52(b), which (3) it did not. The government also maintains that under any conceivable view of the evidence consistent with the jury’s verdict, the Torres brothers and Flores functioned as principal administrators, organizers or leaders of the Organization after October 27, 1986, so that any error in the instruction and verdict forms was harmless. We are unpersuaded by these arguments. It is true that the Torres brothers and Flores did not request an instruction that they could be found in violation of section 848(b)(1) only if they served the Torres Organization as principal administrators, organizers or leaders after October 27, 1986. Rather, they twice sought an instruction that any such determination had to encompass the entire period during which the Organization grossed the $10,-000,000 required to satisfy section 848(b)(2)(B). The district court sensibly responded to this request in the charging conference, observing that “the ten million dollars in the court’s view is a description of the kind of organization rather than a predicate to a particular defendant’s punishable conduct.” Thus, appellants’ request, and their related request for an instruction requiring satisfaction of the $10,000,000 requirement exclusively by proof of gross receipts after October 27, 1986, did not seek with the precision that rule 30 requires an instruction that these appellants had to be found to occupy the leadership roles specified by section 848(b)(1) on or after October 27, 1986 in order to be found in violation of section 848(b). This is not exactly the situation to which Fed.R. Crim.P. 30 is, by its explicit terms, directed, since appellants “stat[ed] distinctly the matter to which [they] objected] and the grounds of [their] objection,” id., but stated a ground different from that which they urge on appeal. As in the case of an inexplicit objection, however, this does not suffice to preserve an objection for appeal, absent plain error (which we shall presently consider). See United States v. Jackson, 569 F.2d 1003, 1010 (7th Cir.), cert. denied, 437 U.S. 907, 98 S.Ct. 3096, 57 L.Ed.2d 1137 (1978); Marbs v. United States, 250 F.2d 514, 516-17 (8th Cir.1957), cert. denied, 356 U.S. 919, 78 S.Ct. 703, 2 L.Ed.2d 715 (1958). These requests did, however, bring the general “ex post facto” matter before the court. As indicated earlier, the district court had previously devoted a portion of its pretrial opinion to this subject. Further, during the argument of appellants’ rule 29 motion