72 F.3d 1453 43 Fed. R. Serv. 280 UNITED STATES of America, Plaintiff-Appellee,v.Lewis Theodore WACKER, Defendant-Appellant.UNITED STATES of America, Plaintiff-Appellee,v.Leroy Allen COOLEY, Defendant-Appellant.UNITED STATES of America, Plaintiff-Appellee,v.John Lee WACKER, Defendant-Appellant.UNITED STATES of America, Plaintiff-Appellee,v.Edith Faye WACKER, Defendant-Appellant.UNITED STATES of America, Plaintiff-Appellee,v.Susan Mary BOYLE, Defendant-Appellant.UNITED STATES of America, Plaintiff-Appellee,v.Michael L. LIPP, Defendant-Appellant.UNITED STATES of America, Plaintiff-Appellee,v.Perl Glen VAN PELT, Defendant-Appellant. Nos. 93-3372, 93-3375, 93-3385, 94-3001, 94-3002, 94-3007and 94-3024. United States Court of Appeals,Tenth Circuit. Dec. 26, 1995.As Modified on Denial of RehearingMarch 11, 1996. Michael L. Lewis, Topeka, Kansas, for Defendant/Appellant Lewis Theodore Wacker. James G. Chappas, Topeka, Kansas, for Defendant/Appellant Leroy Allen Cooley. F.G. Manzanares, Topeka, Kansas, for Defendant/Appellant John Lee Wacker. James P. Moran, Assistant Federal Public Defender, Denver, Colorado (Michael G. Katz, Federal Public Defender, Denver, Colorado, with him on the brief), for Defendant/Appellant Edith Faye Wacker. Edward G. Collister, Jr. of Collister & Kampschroeder, Lawrence, Kansas, for Defendant/Appellant Susan Mary Boyle. Susan M. Hunt, Kansas City, Missouri (John P. O'Connor, Kansas City, Missouri, with her on the brief), for Defendant/Appellant Michael L. Lipp. Stephen W. Kessler, Topeka, Kansas, for Defendant/Appellant Perl Glen Van Pelt. Gregory G. Hough, Assistant United States Attorney, Topeka, Kansas (Randall K. Rathbun, United States Attorney, with him on the brief), for Plaintiff/Appellee. Before EBEL and HENRY, Circuit Judges, and COOK*, District Judge. EBEL, Circuit Judge. 1 Appellants were charged in a fifteen-count superseding indictment with the commission of multiple drug trafficking and weapons offenses arising out of an extensive marijuana distribution conspiracy. Appellant Edith Wacker entered a guilty plea to two of those counts and was sentenced to a term of imprisonment. Edith Wacker now appeals her sentence, arguing that the district court miscalculated the drug quantity involved in her offense conduct, and improperly enhanced her sentence based on her role in the offense. The remaining defendants--Perl Van Pelt, Susan Boyle, John Wacker, Lewis Wacker, Leroy Cooley and Michael Lipp--pleaded not guilty to the charges and were subsequently convicted after a combined jury trial. These defendants now challenge the sufficiency of the evidence for their convictions and appeal the district court's refusal to grant a mistrial based on improper juror communications. They also assert individually a number of additional trial errors. Finally, Lipp, Van Pelt and Cooley each appeal their sentences. We have jurisdiction under 28 U.S.C. Sec. 1291. I. 2 On January 27, 1993, a grand jury returned a fifteen count superseding indictment against the defendants. Each defendant was charged with conspiracy to possess with intent to distribute approximately 2,000 pounds of marijuana, in violation of 21 U.S.C. Sec. 846 (Count 1); four counts of possession with intent to distribute marijuana, in violation of 21 U.S.C. Sec. 841(a)(1) (Counts 4, 5, 6, and 11);1 and two counts of the use of a firearm in connection with a drug trafficking offense or conspiracy, in violation of 18 U.S.C. Secs. 924(c)(1) and (2) (Counts 7 and 12). Each count was also charged on an aiding and abetting theory, pursuant to 18 U.S.C. Sec. 2. 3 Lipp was also charged with one additional count of using a firearm in relation to a drug trafficking offense (Count 2) and three counts of possession of a firearm by a convicted felon, in violation of 18 U.S.C. Sec. 922(g) (Counts 3, 10 and 15). Van Pelt was charged with two counts of possession of a firearm by a convicted felon (Counts 8 and 13), as was Cooley (Counts 9 and 14). 4 Prior to trial, Edith Wacker entered into a plea agreement with the United States Attorney. Pursuant to this agreement, Edith Wacker pleaded guilty to one count of conspiracy to possess with the intent to distribute approximately 2,000 pounds of marijuana in violation of 21 U.S.C. Sec. 846 (Count 1), and one count of unlawful use of a firearm during and in relation to a drug trafficking crime in violation of 18 U.S.C. Sec. 924(c) (Count 7). The remaining charges against Edith Wacker were dropped pursuant to the agreement. The other codefendants entered not guilty pleas. 5 At the trial of these six codefendants, persuasive evidence showed that the defendants operated a large marijuana harvesting and distribution operation on the farm of Theo and Esther Wacker (parents of defendants Edith, John and Lewis Wacker), located in Lincoln County, Kansas, and at the Van Pelt residence in Perry, Kansas. Police investigation began on July 20, 1990, when a confidential informant told Officer Larry Beagley of the Ellsworth Police Department that John, Lewis and Edith Wacker were harvesting marijuana on the Wackers' farm. Officer Beagley conducted surveillance of the Wacker farm on four separate occasions between August 29 and September 10, 1990. Each time, he observed marijuana plants growing on a separate parcel of property owned by Sidney Wacker, which property was known among the parties as "Down Yonder."2 Beagley relayed this information to the Kansas Bureau of Investigation ("KBI"). 6 On September 8, 1990, the KBI Crime Hot Line received a phone call from an anonymous woman who stated that a marijuana harvesting, drying and processing operation was being conducted at the Wacker farm. In response to Beagley's information, KBI Special Agent Rick Atteberry conducted aerial surveillance of the Wacker farm on September 10, 1990, and observed marijuana plants growing in a tree line adjacent to some outbuildings. 7 At approximately 12:18 a.m. on September 16, 1990, Trooper Mike Weigel of the Kansas Highway Patrol conducted a traffic stop of a pickup truck with a camper top driven by appellant Lipp. Lewis Wacker's wife, Carla Wacker, ("Carla") was a passenger in the truck, which was registered to Susan Boyle and Edith Wacker. Trooper Weigel issued Lipp a warning for a defective registration tag light, then asked to search the truck for guns or contraband. Lipp consented. Weigel searched the passenger compartment and discovered a set of brass knuckles, a large box of trash bags, two corn knives, a roll of rope, and two rolls of duct tape. A search of the rear camper shell of the truck yielded a bag containing a 9 mm pistol; a pair of gloves smelling of fresh cut marijuana; a machete; and a white paper bag containing marijuana. Lipp and Carla were placed under arrest and taken into custody.3 8 Trooper Weigel then searched Carla's purse, finding a spoon with white residue and some white powder that was later found to be methamphetamine. In exchange for a grant of immunity, Carla agreed to serve as an informant for the KBI. Carla told government authorities that she, Lewis Wacker, Edith Wacker, Lipp, Van Pelt, Boyle and Cooley were involved in harvesting marijuana on the Wacker farm, and that at that time they were in the process of harvesting approximately 1,000 pounds. 9 Based on Carla's information that Van Pelt was going to be bringing marijuana into the Theo Wacker residence on the Wacker farm, Officer Beagley and KBI agents conducted further surveillance of the farm on September 16, 1990. At about 9:55 a.m., Beagley observed a Suburban belonging to Van Pelt and Boyle arrive at the farm and drive into a metal shed on the property. About thirty minutes later the Suburban left the shed and drove into the "Down Yonder" property where it disappeared into a tree-lined area for approximately fifteen minutes. KBI agents returned to the spot that evening and discovered six plastic trash bags containing processed marijuana. The Suburban returned to the shed on the Wacker farm at about 10:50 a.m., at which point Officer Beagley saw a fire burning and several people taking objects out of the shed and tossing them into the fire. He tentatively identified Lewis Wacker as one of the participants. John and Lewis Wacker later admitted that the conspirators were burning between 300 and 700 pounds of processed marijuana because they feared, correctly, that they were under police surveillance. 10 Around noon on the following day, September 17, KBI agents stopped the Suburban and found Boyle, Van Pelt and Cooley inside. The three were ordered out of the vehicle by the agents, who conducted pat down searches and discovered large amounts of cash in the possession of each suspect. The agents asked for and received permission to search the vehicle, and conducted a cursory search. The agents saw Boyle's open purse, in which a large wad of folded currency was visible, on the rear seat of the vehicle. The agents obtained a search warrant, and searched the contents of the purse and the trailer attached to the Suburban. The purse was found to contain, among other things, safe deposit box keys and several envelopes containing thousands of dollars in cash. A marijuana plant was found in the trailer. Van Pelt, Boyle and Cooley were placed under arrest. During routine interrogation, Van Pelt volunteered incriminating statements to police. He informed one agent that he had intended to harvest marijuana but had not yet done so, and if the agents had stopped him two days later they would have found marijuana. He told another police officer that marijuana could not have been found in the vehicle because he had "made damn sure there wasn't anything there." 11 KBI agents executed a search warrant for the Wacker farm on September 17, 1990. During the search, the agents seized numerous incriminating items, including: six trash bags of marijuana; 34 marijuana plants; a .22 caliber handgun; the "front sheets" used to track the money owed to each conspirator for his or her contributions to the harvesting operation; various marijuana processing materials with small amounts of marijuana residue; and drug paraphernalia. 12 It was reported in the presentence reports, and found by the district judge during sentencing to be accurate, that on September 19, 1990, Edith Wacker told KBI agents that she and her coconspirators had planned to harvest approximately 2,000 pounds of marijuana but had been stopped before reaching that goal. She informed the agents that she kept records of the operation (the "front sheets") to ensure that each of the participants would be paid for their work and explained that the abbreviations on the front sheets were shorthand references to Lipp, Cooley, Boyle, Carla Wacker, Van Pelt, Lewis Wacker, and herself. Her statement implicated all codefendants in the case. 13 KBI agents obtained a warrant and conducted a search of Van Pelt's home on September 19, 1990. The search revealed a number of items associated with marijuana processing, including marijuana seeds, books on marijuana growing, and a number of scales. Agents also found drug paraphernalia, counter-surveillance equipment, and several firearms. Among them were a loaded 9 mm semiautomatic pistol with two clips, found in a file cabinet, and a .22 caliber pistol with one speed loader, found in a drawer in the kitchen. Agents also seized records of a 1990 trip to New York, a letter from Edith Wacker regarding marijuana trafficking, photographs detailing marijuana being grown, processed and baled, and a hand-drawn map detailing the path to the "Down Yonder" area of the Wacker farm. 14 At trial, Carla Wacker testified that she had become aware of the marijuana conspiracy in 1989. She described the processing operation in detail and testified that Lipp had told her that, after baling, Van Pelt would take the marijuana to New York for sale. She testified that she, Boyle, Lewis Wacker, Edith Wacker, Lipp and Cooley picked marijuana. Van Pelt determined how much each would be paid. Carla also testified that Edith Wacker usually wore her .22 caliber pistol while out in the field. 15 Further testimony was offered. Cody Wacker, John Wacker's son, testified that he had observed marijuana growing on the farm in the summer of 1990. Kevin Adams, an inmate with whom Van Pelt and Cooley were incarcerated, testified to incriminating statements made by both of those defendants. Gary Conn, Edith Wacker's ex-husband, testified that he had participated in a substantial marijuana harvesting and processing operation run by Van Pelt and Boyle in the 1970s, and that he recalled weapons being present throughout. He specifically recalled automatic weapons. Van Pelt's brother testified that Van Pelt had not had a visible source of income for at least ten years. The government also presented expert testimony as to the uses of firearms in drug trafficking operations such as the one at issue here. 16 All six defendants who stood trial ("trial defendants") were convicted by the jury of at least the conspiracy count, one or more counts of possession with intent to distribute marijuana, and one or more counts of use of a firearm in relation to a drug trafficking offense. All of the defendants timely raised these appeals.4 II. 17 The trial defendants mount several attacks on their convictions, asserting insufficient evidence, errors in trial procedure, errors in the admission of evidence, and constitutional errors in the application to them of various statutes. We address each of these arguments in turn. A. Sufficiency of the Evidence 18 All six trial defendants argue that the evidence was insufficient to support their convictions on the conspiracy and substantive charges. "In reviewing the sufficiency of evidence to sustain a jury's guilty verdict, we examine the evidence in the light most favorable to the government in order to determine whether the evidence ... together with all reasonable inferences to be drawn therefrom, is substantial enough to establish guilt beyond a reasonable doubt." United States v. Johnson, 42 F.3d 1312, 1319 (10th Cir.1994), cert. denied, --- U.S. ----, 115 S. Ct. 1439, 131 L. Ed. 2d 318 (1995) (internal quotation marks omitted). We reverse only if no rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt. United States v. Grimes, 967 F.2d 1468, 1472 (10th Cir.), cert. denied sub nom. McGlynn v. United States, 506 U.S. 927, 113 S. Ct. 355, 121 L. Ed. 2d 269 (1992). Upon reviewing the record, we find the evidence more than adequate to support the convictions, both as to the conspiracy count and the substantive counts. 19 The trial defendants also assert that there was insufficient evidence to support their convictions of using a firearm during and in relation to a drug trafficking offense in violation of 18 U.S.C. Sec. 924(c)(1) (Counts 2, 7 and 12).5 Count 2 referred to the 9 mm pistol found in Lipp's truck, Count 7 referred to Edith Wacker's .22 pistol, and Count 12 referred to the 9 mm pistol found in a file cabinet at the residence Boyle shared with Van Pelt. Appellants assert that the evidence does not support the inference that they "used" the firearms within the meaning of the statute.6 20 At the time of appellants' trial, the governing rule in this Circuit was that a conviction for "use" was supported if the government established: (1) the defendant had "ready access" to the firearm; and (2) the firearm was an "integral part" of the criminal undertaking and increased the likelihood that the undertaking would succeed. United States v. McKinnell, 888 F.2d 669, 675 (10th Cir.1989). To show that a firearm was readily accessible, we had held that the government needed to show only that "the firearm was available to the defendant in the vicinity where the drug trafficking offense took place." United States v. Parrish, 925 F.2d 1293, 1297 (10th Cir.1991). 21 Subsequent to briefing and oral argument on this appeal, however, the Supreme Court clarified what evidence is necessary to support a conviction for "use" under section 924(c). In Bailey v. United States, --- U.S. ----, 116 S. Ct. 501, 133 L. Ed. 2d 472 (1995), the Court held that "[t]o sustain a conviction under the "use" prong of Sec. 924(c)(1), the Government must show that the defendant actively employed the firearm during and in relation to the predicate crime." Id. at ----, 116 S.Ct. at 509. By way of illustration, the Court provided examples of those activities that constitute "active employment" of a firearm, and those that do not. See id. at ---- - ----, 116 S. Ct. at 508-09. We find the Court's holding and examples controlling of the greenlaurie@example.net 22 First, the Court held that "[a] defendant cannot be charged under Sec. 924(c)(1) merely for storing a weapon near drugs or drug proceeds.... If the gun is not disclosed or mentioned by the offender, it is not actively employed, and it is not 'used.' " Id. Accordingly, the Court reversed the section 924(c) convictions of two defendants. As to one defendant, the Court found no evidence of "active employment" of a firearm when the firearm was found in a bag locked in the trunk of the car defendant was driving when arrested. Id. at ----, 116 S.Ct. at 509. We find no meaningful distinction between the facts of that case and those surrounding the firearm charged in Count 2, which was found in a bag in the rear camper shell of the truck Lipp was driving when he was stopped. We therefore reverse Lipp's conviction on this Count. 23 Similarly, the Court in Bailey found no evidence of active employment of a firearm where an unloaded, holstered gun was found "locked in a footlocker in a bedroom closet" of the defendant's home. Id. at ----, 116 S.Ct. at 509. While the 9 mm pistol found at Van Pelt's home was loaded, and the parties dispute whether the file cabinet in which it was found was locked, we again find no meaningful distinction between the facts surrounding Count 12 and those found legally insufficient in Bailey. There is nothing in the record to suggest that Van Pelt's gun was mentioned, displayed, brandished or accessed in any way during the course of the drug offenses for which the trial defendants were convicted. We therefore reverse the convictions of Boyle, Van Pelt, and Cooley on Count 12.8 24 It is a closer question whether the government presented sufficient evidence regarding the firearm charged in Count 7, the .22 pistol belonging to Edith Wacker. It is apparent from the record that Edith carried the gun on her person while picking marijuana. The evidence is also sufficient to demonstrate that the pistol was carried in furtherance of the conspiracy, and that it was reasonably foreseeable to the other coconspirators that it would be so carried, thus rendering them also responsible for the gun. See Pinkerton v. United States, 328 U.S. 640, 646-47, 66 S. Ct. 1180, 1183-84, 90 L. Ed. 1489 (1946); United States v. Davis, 1 F.3d 1014, 1017 (10th Cir.1993) (applying Pinkerton theory to 924(c) charge). Inexplicably, however, Count 7 does not charge appellants under section 924(c)'s "carry" prong; the indictment alleges only that appellants "used" the gun. 25 In Bailey, the Supreme Court explained that: 26 Under the interpretation we enunciate today, a firearm can be used without being carried, e.g., when an offender has a gun on display during a transaction ...; and a firearm can be carried without being used, e.g., when an offender keeps a gun hidden in his clothing throughout a drug transaction. 27 --- U.S. at ----, 116 S. Ct. at 507. At appellants' trial, the most damaging testimony regarding Edith Wacker's firearm was the following, offered by Carla Wacker: 28 Q: Friday you identified a gun ... Do you recall that? 29 A: Yes, sir. 30 Q. At any time when you were picking, did you see the gun present? 31 A. Edith usually had her pistol. 32 Q. Okay. You identified that as Edith's pistol? 33 A. Yes, sir. 34 Q. Okay. Would she be wearing that while she was picking? 35 A. Yes, sir. 36 Q. During the time that you were picking the marijuana ... what type of clothing would people wear while they were in the fields picking? * * * 37 A. Jeans, long sleeves. 38 Q. Okay. And to your knowledge, why were the jeans and long sleeved shirts worn? 39 A. So that you didn't get weed burn and stuff like that. 40 (R.O.A. Vol. XXXVIII, at 995-96). In addition, the government presented testimony from Cody Wacker that Edith kept two handguns in her house. 41 This evidence, we believe, was sufficient to support a conviction for "use" of a firearm under our then-existing standard. See Parrish, 925 greenlaurie@example.net However, we cannot say how a jury might decide this issue if properly instructed under the law as defined by Bailey. The question of whether Edith Wacker's gun was "used" under section 924(c) is best left to the determination of a properly instructed jury. Cf. Jackson v. Virginia, 443 U.S. 307, 319, 99 S. Ct. 2781, 2789, 61 L. Ed. 2d 560 (1979) (court reviewing sufficiency of the evidence should impinge upon jury discretion only to the extent necessary to guarantee the fundamental protection of the law). Accordingly, we remand this issue to the district court for a new trial, at which time further evidence on the issue of "use" may be presented. 42 We note that our remand is not inconsistent with the Double Jeopardy Clause. While reversal of a conviction on the grounds of insufficient evidence precludes retrial of the defendant, Burks v. United States, 437 U.S. 1, 98 S. Ct. 2141, 57 L. Ed. 2d 1 (1978), we do not find that rule applicable here. The reasoning in Burks was twofold. First, by reversing a conviction for insufficient evidence, the reviewing court is actually making a determination that the trial court erred in failing to direct a verdict of acquittal on the evidence; accordingly, the defendant should be treated as though he or she were acquitted. Id. at 10, 98 S.Ct. at 2146-47. Second, the prosecution may not, consistent with the Double Jeopardy Clause, be afforded a second opportunity to supply evidence which it "failed to muster in the first proceeding." Id. at 11, 98 S.Ct. at 2147. Neither of these concerns is present in this case. Under the "use" standard in place at the time, the evidence adduced at appellants' trial was sufficient to sustain the section 924(c) convictions. Thus, the district court did not err in refusing to grant a judgment of acquittal because of insufficient evidence on those counts. Moreover, the government here cannot be held responsible for "failing to muster" evidence sufficient to satisfy a standard which did not exist at the time of trial. See United States v. Weems, 49 F.3d 528, 530-31 (9th Cir.1995) (retrial not barred by double jeopardy where prosecutor failed to prove element of crime that, at time of trial, did not need to be proved) (citing Linam v. Griffin, 685 F.2d 369, 373-74 (10th Cir.1982), cert. denied, 459 U.S. 1211, 103 S. Ct. 1207, 75 L. Ed. 2d 447 (1983)). 43 We find the present situation analogous to that in Lockhart v. Nelson, 488 U.S. 33, 109 S. Ct. 285, 102 L. Ed. 2d 265 (1988). There, the Supreme Court found retrial appropriate where a certain item of evidence was erroneously admitted at trial, and without which the prosecution's proof was insufficient to sustain the conviction. The Court reasoned that had the evidence been properly excluded at trial, the prosecution would have attempted to offer additional evidence to satisfy its burden. Id. at 42, 109 S.Ct. at 291-92. Thus, the reversal was one for "trial error" rather than for pure insufficiency of evidence, and retrial did not violate double jeopardy. Id. at 33, 109 S.Ct. at 286-87. Here, our reversal is analogous to one based on trial error: the legal standard under which the jury was instructed and under which the government presented its proof was incorrect. We conclude that "whenever a conviction is reversed solely for failure to produce evidence that was not theretofore generally understood to be essential to prove the crime, ... double jeopardy does not bar reprosecution." Linam, 685 F.2d at 379 (Anderson, Dist. J., concurring). 44 Accordingly, we remand appellants Van Pelt, Boyle, Cooley, John Wacker and Lewis Wacker to the district court for retrial on the limited issue presented in Count 7 of whether Edith Wacker's gun was "used" within the meaning of section 924(c). The jury should be instructed under the Bailey standard, and the government may present additional evidence, if available, relevant to the issue of whether this firearm was used within the meaning of the statute.10B. Improper Juror Communications 45 All six trial defendants also argue that the district court erred in failing to grant a mistrial on the basis of improper communications between jurors during voir dire. A ruling on a motion for mistrial is within the sound discretion of the district court and will not be disturbed absent a clear abuse of that discretion. United States v. Berryhill, 880 F.2d 275, 278 (10th Cir.1989), cert. denied, 493 U.S. 1049, 110 S. Ct. 853, 107 L. Ed. 2d 846 (1990). 46 Jury selection in the defendants' combined trial commenced on June 15, 1993. Over the course of the day, the district judge repeatedly admonished the venirepersons not to discuss the case with anyone. The next morning, prior to the resumption of voir dire, the court clerk was given the following note by a prospective juror: 47 During the questioning of the Jury yesterday the defense attorneys made some remarks that seem to conflict with each other or at least don't make sense to me. 48 They said that we were not to take into account how many witnesses were for or against, that numbers didn't matter. Then they said that we should give no special attention or extra consideration to a law enforcement officer's testimony, to treat it like all others. They then made a remark to the effect that when there was conflicting testimony that we should lean toward the defense. They also made a remark that we should not try to read body language to try to determine who is not telling the truth. 49 My question is simply this, how are we supposed to come to a decision based on the testimony. The way they seem to present it the tie goes to the defense. 50 /s/ Michael Milleson 51 After receiving Juror Milleson's note, the district judge held an in chambers conference during which all defense attorneys moved for a mistrial. Alternatively, defense counsel requested that the court examine Milleson to ascertain the nature of the discussions and the number of prospective jurors involved. The court denied the mistrial but elected to examine Milleson in camera. 52 During this examination, the district judge learned that Milleson, confused by the questioning of one of the trial defendants' attorneys, had discussed certain trial-related matters with three other venirepersons. Specifically, Milleson and the other jurors had discussed the credibility of prospective witnesses (especially police officers) and the reservations they would have in reaching a verdict if the defense were only to put on a few witnesses. Upon learning the nature of the jurors' conversation, defense counsel renewed their motions for mistrial, and alternatively requested that the court examine each juror that participated in the conversations. The district court denied both requests. The court instead excused Juror Milleson for cause, and admonished the jury in a lengthy curative instruction. 53 Appellants rely on a number of cases concerning improper third party communications with jurors--specifically, Remmer v. United States, 347 U.S. 227, 74 S. Ct. 450, 98 L. Ed. 654 (1954); United States v. Hornung, 848 F.2d 1040 (10th Cir.1988), cert. denied sub nom. Green v. United States, 489 U.S. 1069, 109 S. Ct. 1349, 103 L. Ed. 2d 817 (1989); and United States v. Day, 830 F.2d 1099 (10th Cir.1987). Appellants argue that these cases establish a rule of presumptive prejudice whenever a jury is exposed to external information in contravention of a district court's instruction. Appellants cite no authority extending this rule to internal juror communications, but argue that "it is obvious ... as a matter of logic" that it would be so applied. Brief of Appellant John greenlaurie@example.net. Although we are uncertain that the presumption of prejudice called forth in Remmer, Hornung and Day would apply to communications among venirepersons, as opposed to communications from outside sources, we need not resolve that issue here because, in any event, we are persuaded that appellants were not prejudiced in this case. 54 In Remmer, the Supreme Court held that any private communication or contact with a juror about a matter pending before the jury is deemed presumptively prejudicial. Remmer, 347 U.S. at 229, 74 S.Ct. at 451. This presumption of prejudice, however, is not conclusive; the burden is upon the government to establish, after notice to and hearing of the defendant, that any juror contact was harmless to the defendant. Hornung, 848 F.2d at 1044-45 (citing Remmer, 347 U.S. at 229, 74 S.Ct. at 451). In the proceedings below, appellants' principal concern was that "[p]otential juror bias in favor of law enforcement officers" existed during their trial. See Brief of Appellant greenlaurie@example.net. Accordingly, the question becomes whether the appellants suffered any prejudice at trial because of a perceived juror bias in favor of law enforcement. 55 The Supreme Court has held that the test of juror impartiality is whether "the juror can lay aside his impression or opinion and render a verdict based on the evidence presented in court." Irvin v. Dowd, 366 U.S. 717, 723, 81 S. Ct. 1639, 1643, 6 L. Ed. 2d 751 (1961). In situations such as the one before us, when the alleged improper remarks were made by one potential juror and heard by other potential jurors during the jury selection process, we believe this is the proper test for evaluating claims of prejudice. When juror impartiality is questioned, the trial court has wide discretion in evaluating the competency of a juror to sit, and its decision will not be interfered with except for a clear abuse of discretion. Berryhill, 880 F.2d at 279; Hornung, 848 greenlaurie@example.net. We conclude that the evidence in the record is sufficient to rebut any claim of prejudice or juror bias. 56 After receiving Juror Milleson's note, the trial judge examined Milleson in camera to determine the precise nature and the extent of the conversations. Appellants did not object to the in camera procedure, nor did they seek to ask additional questions of Milleson. In any event, the procedure followed by the trial judge was quite similar to that approved in Day, where the defendant's claim of prejudice resulting from an improper conversation with a seated juror was overcome when the trial judge conducted a brief hearing, elicited the content of the conversation, and made a self-determination that no bias existed. 830 greenlaurie@example.net. Here, after conducting the examination, the trial judge concluded that Milleson was not so much biased in his opinion as he was confused by defense counsel's remarks during voir dire questioning. Nevertheless, the court excused Milleson from the venire and issued a lengthy instruction to the remaining venirepersons--an instruction specifically directed at clarifying any confusion defense counsel's remarks may have caused. Significantly, appellants did not seek to remove any of the other jurors from the panel by way of peremptory challenge, even though one petit juror, Juror Freeman, was identified as having participated in the improper communications with Milleson.11 57 The district judge was of the opinion that by excusing Milleson and issuing the cautionary instruction, any possible prejudice against the defendant would be cured. We agree. The district judge is entitled to rely upon its self-evaluations of allegedly biased jurors in determining actual juror bias. Day, 830 F.2d at 1105 (citing Smith v. Phillips, 455 U.S. 209, 217 n. 7, 102 S. Ct. 940, 946 n. 7, 71 L. Ed. 2d 78 (1982)). Moreover, "even if there were some risk of prejudice, here it is of the type that can be cured with proper instructions, and juries are presumed to follow their instructions." Zafiro v. United States, 506 U.S. 534, 540, 113 S. Ct. 933, 939, 122 L. Ed. 2d 317 (1993) (internal quotation marks omitted). Because the district court is in the best position to judge the effect of improper statements on a jury and the sincerity of the jurors' pledge to abide by the court's instructions, its assessment is entitled to great weight. United States v. Gibbons, 607 F.2d 1320, 1330-31 (10th Cir.1979); United States v. Tegzes, 715 F.2d 505, 508-09 (11th Cir.1983). Accordingly, we reject the trial defendants' argument that a mistrial should have been granted. C. Motions for Severance 58 Boyle, Lewis Wacker and John Wacker argue that the district court erred by failing to sever each of their trials from that of their codefendants. Each asserts that he or she is less culpable than the others and that the jury was unable to compartmentalize the evidence against each defendant. 59 A district court's decision denying a motion to sever is reviewed for abuse of discretion. United States v. Rogers, 925 F.2d 1285, 1287 (10th Cir.), cert. denied, 501 U.S. 1211, 111 S. Ct. 2812, 115 L. Ed. 2d 985 (1991). The defendant bears the "heavy burden of demonstrating prejudice to his case." Id. To meet this burden, defendant must demonstrate actual prejudice and not merely a negative spill-over effect from damaging evidence presented against codefendants. United States v. Cardall, 885 F.2d 656, 667-68 (10th Cir.1989). Nor is it sufficient to show that one defendant is less culpable than the remaining codefendants. United States v. Youngpeter, 986 F.2d 349, 353 (10th Cir.1993). The appellants here allege no facts from which we could infer prejudice or an inability of the jury to compartmentalize the evidence against each codefendant. Indeed, the fact that John and Lewis Wacker were each acquitted of two of the charges against them suggests that the jury was able to compartmentalize the evidence against each defendant. Because prejudice is not shown by "a hypothesis of prejudice," Youngpeter, 986 F.2d at 353, we find no indication that the district court abused its discretion in denying the motions for severance. D. Evidentiary Issues 1. Admission of Prior Bad Acts Evidence 60 Appellants Boyle and Van Pelt argue that the district court erred in allowing the government to admit evidence of their prior bad greenlaurie@example.net. Boyle and Van Pelt both invoke Federal Rule of Evidence 404(b), which provides as follows: 61 Evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show action in conformity therewith. It may, however, be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident, provided that upon request by the accused, the prosecution in a criminal case shall provide reasonable notice in advance of trial, or during trial if the court excuses pretrial notice on good cause shown, of the general nature of any such evidence it intends to greenlaurie@example.net. 62 Fed.R.Evid. 404(b). Over appellants' objections, the district court allowed the testimony of Pam Stewart that she and Van Pelt picked marijuana in 1981; the testimony of Maurice Heberly that he purchased wild Kansas marijuana from Van Pelt back in 1982 and 1984; and the testimony of Gary Conn that Van Pelt and Boyle had been involved in marijuana processing in 1977 and 1980. The district court concluded that the evidence was properly admissible pursuant to Rule 404(b) for the purpose of showing intent, motive and plan in the crimes alleged in the indictment. 63 The standard of review for a district court's admission of evidence pursuant to Fed.R.Evid. 404(b) is for abuse of discretion. United States v. Grissom, 44 F.3d 1507, 1513 (10th Cir.), cert. denied, --- U.S. ----, 115 S. Ct. 1720, 131 L. Ed. 2d 579 (1995). It is presumed that a defendant is protected from undue prejudice if the following four requirements are met: 64 (1) the government offered the evidence for a proper purpose; 65 (2) the evidence was relevant; 66 (3) the trial court made a Fed.R.Evid. 403 determination that the probative value of the evidence is not substantially outweighed by its potential for unfair prejudice; and 67 (4) the district court submitted a limiting instruction. 68 Id.; Huddleston v. United States, 485 U.S. 681, 691-92, 108 S. Ct. 1496, 1502, 99 L. Ed. 2d 771 (1988). Boyle and Van Pelt assert error only as to the first and third of these requirements--namely, that the prior bad acts evidence was admitted for an improper purpose and that it was unfairly prejudicial under Rule 403. We address these arguments in turn. 69 First, we believe the district court admitted the challenged evidence for a proper purpose. At trial, Boyle and Van Pelt disavowed any criminal intent in connection with the drug conspiracy. They also disputed any ownership or control over the drugs or other contraband. The government thus sought to demonstrate appellants' intent and plan by showing their continued involvement since the late 1970s in a marijuana trafficking conspiracy operating out of Kansas. The testimony of Stewart, Heberly and Conn was admitted for this limited purpose, and the jury was instructed to consider it only in this manner. Our previous cases recognize the probative value of uncharged acts evidence to demonstrate a criminal defendant's intent and plan in the context of a conspiracy prosecution. See United States v. Record, 873 F.2d 1363, 1375 (10th Cir.1989) (collecting cases). We therefore agree with the district court that the evidence was properly admitted to show appellants' intent and plan. 70 Second, Boyle and Van Pelt argue that even if the evidence was admitted for a proper purpose under Rule 404(b), it nevertheless failed to satisfy the balancing test of Rule 403.12 See United States v. Cuch, 842 F.2d 1173, 1176 (10th Cir.1988) (even if prior bad acts evidence satisfies Rule 404(b), trial court must still balance probative value and prejudicial effect under Rule 403). Specifically, appellants argue that because the incidents to which Stewart, Heberly and Conn testified were unduly remote in time to the crimes charged, the probative worth of the evidence was substantially outweighed by the danger of unfair prejudice. 71 The admission of evidence under Rule 403 is reviewed only for an abuse of discretion. United States v. Rackstraw, 7 F.3d 1476, 1482 (10th Cir.1993). In considering the prejudicial effect of prior bad acts that are temporally remote, we have eschewed any " 'absolute rule regarding the number of years that can separate offenses. Rather, the court applies a reasonableness standard and examines the facts and circumstances of each case.' " Cuch, 842 F.2d at 1178 (quoting United States v. Franklin, 704 F.2d 1183, 1189 (10th Cir.), cert. denied, 464 U.S. 845, 104 S. Ct. 146, 78 L. Ed. 2d 137 (1983)). Applying this standard, we conclude that the proffered evidence is probative of a material issue and not unduly prejudicial. Although the bad acts testified to at trial occurred well before the offenses charged in the indictment, the prosecution used this testimony to show a long-standing pattern of drug activity from the late 1970s up until the time of appellants' arrest in 1990. Viewed in this light, the evidence is not unrelated and remote, but is integrally related to the criminal activity charged in the indictment. See United States v. Record, 873 F.2d 1363, 1372 n. 5 (10th Cir.1989) (uncharged prior acts that are "inextricably intertwined" with the charged crime are admissible); United States v. Misle Bus & Equip. Co., 967 F.2d 1227, 1234-35 (8th Cir.1992) (admission of historical evidence concerning conspiracy did not violate Rule 403 even though it predated the limitations period and was remote in time). Accordingly, we reject appellants' claim that the district court abused its discretion in admitting the evidence. 72 2. Motions to Suppress Evidence Seized During Vehicle Searches 73 Appellants Lipp and Boyle each allege violations of the Fourth Amendment in the admission of certain items of greenlaurie@example.net. Lipp argues that the district court should have granted his motion to suppress evidence found during a September 16, 1990 search of his truck. Similarly, Boyle argues that the district court erroneously denied her pretrial motion to suppress all evidence seized after the police stopped and searched her Suburban on September 17, 1990. We review the factual findings underlying the district court's denial of a motion to suppress evidence for clear error. United States v. Flores, 48 F.3d 467, 468 (10th Cir.), cert. denied, --- U.S. ----, 116 S. Ct. 122, 133 L. Ed. 2d 72 (1995). However, the ultimate determination of reasonableness under the Fourth Amendment is a legal question which we review de novo. Id. 74 (a) Denial of Lipp's motion to suppress 75 Lipp challenges the district court's ruling that the evidentiary items seized from his truck were admissible as fruits of a consensual search. Lipp contends that although he consented to a search of the passenger cab of his truck, his consent did not extend to the rear camper shell area. Thus, Lipp argues, the evidence seized from the rear of the truck--marijuana seeds, residue, processed marijuana, camouflage netting, a 9 mm handgun, and a machete--should have been greenlaurie@example.net. 76 The scope of a consent search is limited by the breadth of the consent given. United States v. Pena, 920 F.2d 1509, 1514 (10th Cir.1990), cert. denied, 501 U.S. 1207, 111 S. Ct. 2802, 115 L. Ed. 2d 975 (1991). In the instant case, Lipp was pulled over for a defective license plate light. Trooper Weigel issued Lipp a warning and then asked Lipp for permission to search the car for guns or contraband. Lipp replied, "Yeah, go ahead and look if you want." After searching the passenger cab and finding some knives, trash bags and a set of brass knuckles, Trooper Weigel opened up the camper shell and conducted a search of the truck's bed. At no time during this search did Lipp object or attempt to confine the scope of the search. In denying Lipp's suppression motion, the trial judge found that Lipp consented to the search, that Lipp's consent was specific and voluntarily given, and that the search of the rear camper area did not exceed the scope of the search. We agree. 77 The standard for measuring the scope of a suspect's consent is that of " 'objective' reasonableness--what would the typical reasonable person have understood by the exchange between the officer and the suspect?" Florida v. Jimeno, 500 U.S. 248, 251, 111 S. Ct. 1801, 1803-04, 114 L. Ed. 2d 297 (1991). In Jimeno, the Court held that a suspect's consent to search his car for drugs included consent to search a container in the car that might reasonably hold drugs. Id. at 249, 111 S.Ct. at 1802-03. In so holding, the Court noted that the suspect had given the police officer a general consent to search the car, and had placed no explicit limitation on the scope of the search. Id. at 251, 111 S.Ct. at 1803-04. We too have held that where a suspect does not limit the scope of a search, and does not object when the search exceeds what he later claims was a more limited consent, an officer is justified in searching the entire vehicle. See, e.g., Pena, 920 F.2d at 1515 ("[F]ailure to object to the continuation of the search under these circumstances may be considered an indication that the search was within the scope of the consent."); United States v. Deases, 918 F.2d 118, 122 (10th Cir.1990) ("Consent to search a car means to search the entire car and whatever is in it, unless such consent is otherwise restricted."), cert. denied, 501 U.S. 1233, 111 S. Ct. 2859, 115 L. Ed. 2d 1026 (1991). Lipp's argument may be disposed of in a similar fashion. Trooper Weigel asked Lipp generally if he could search the car for drugs or contraband. Lipp consented, but placed no limits on the search. Neither did he later object when the search extended to the bed of the truck. Under these circumstances, we conclude that the search of Lipp's truck was valid. 78 (b) Denial of Boyle's suppression motion 79 The district court ruled that the items seized during the search of Boyle's Suburban were admissible because, inter alia, the police had probable cause to believe that the vehicle contained contraband. See United States v. Crabb, 952 F.2d 1245, 1246 (10th Cir.1991) (given probable cause to believe that the vehicle contains contraband, the Constitution does not require law enforcement agents to obtain a warrant before searching the vehicle), cert. denied, 504 U.S. 925, 112 S. Ct. 1981, 118 L. Ed. 2d 579 (1992). After reviewing the record and the district court's findings, we agree.13 80 Prior to stopping the Suburban, the police obtained information from Carla Wacker, the government's confidential informant, indicating that the vehicle was being used to transport processed marijuana from the drug operation for distribution in New York, and that the occupants (identified as Van Pelt, Boyle and Cooley) were each carrying large amounts of cash from drug transactions. Carla Wacker also informed police that the vehicle was parked at a campsite in the area, and that Van Pelt, Boyle and Cooley were camping in the area temporarily while harvesting marijuana on the Wacker farm. Based on this information, the police conducted aerial surveillance of the Wacker farm. On September 16, 1990, surveillance agents observed the Suburban going into the "Down Yonder" area of the farm. The agents subsequently searched the area where the vehicle had been and found six plastic trash bags containing processed marijuana. Because the police surveillance largely corroborated the information provided by Carla Wacker, we agree that the agents had probable cause to believe the vehicle was being used to transport marijuana and that the vehicle likely contained drugs, weapons, or other instrumentalities of crime. See Illinois v. Gates, 462 U.S. 213, 237-38, 103 S. Ct. 2317, 2331-32, 76 L. Ed. 2d 527 (1983) (information provided by police informant may provide probable cause to search, "particularly when supplemented by independent police investigation"). Because they possessed probable cause, the police were not required to obtain a warrant before searching the vehicle. United States v. Arzaga, 9 F.3d 91, 94 (10th Cir.1993). 3. Admission of Lipp's Prior Convictions 81 Appellant Lipp contests the admission at trial of journal entries detailing his prior felony convictions.14 We review the district court's decision whether to admit evidence of a defendant's prior crimes for abuse of discretion. United States v. Brinklow, 560 F.2d 1003, 1006 (10th Cir.1977), cert. denied, 434 U.S. 1047, 98 S. Ct. 893, 54 L. Ed. 2d 798 (1978). 82 Lipp was charged in Counts 3, 10 and 15 of the indictment with being a felon in possession of a firearm in violation of 18 U.S.C. Sec. 922(g)(1). This statute makes it "unlawful for any person ... who has been convicted in any court of a crime punishable by imprisonment for a term exceeding one year ... to ... possess in or affecting commerce, any firearm or ammunition." Id. At trial, the government offered the journal entries to prove an essential element of the crime under section 922(g)(1)--i.e., that Lipp was a convicted felon. Lipp objected to the admission of the journal entries and offered to stipulate to the fact of his prior convictions. When the government refused to accept the stipulation, the district court overruled Lipp's objection and allowed the government to introduce the evidence. Lipp contends this was an abuse of discretion. 83 The government argues that this issue is controlled by our prior decision in Brinklow. In Brinklow, we held that the trial court did not abuse its discretion by refusing a defendant's request to strike from the indictment and keep from the jury all references to his previous felony convictions. 560 greenlaurie@example.net. Recognizing that a prior felony conviction is an essential element of the offense, we held that "the government is not required to accept such [a stipulation] and may insist upon proving all essential elements of its case." Id. Although we remain faithful to our opinion in Brinklow, we do not believe that it is determinative of the case before us. 84 Lipp's request differs from the situation in Brinklow. In Brinklow, the defendant "proposed that [the] jury instructions specify only those essential elements of the crime other than that of a previous felony conviction and that the jury be instructed that there were additional necessary elements with which they did not need to be concerned." 560 greenlaurie@example.net. By contrast, Lipp's stipulation did not seek to keep from the jury the fact of his felony status, but only the nature and underlying circumstances of his prior crimes. We believe this distinction to be significant. 85 Whereas the fact of a defendant's prior felony conviction is material to a felon in possession charge, the nature and underlying circumstances of a defendant's conviction are not. See United States v. Barker, 1 F.3d 957, 959 n. 3 (9th Cir.1993) ("The underlying facts of the prior conviction are completely irrelevant under Sec. 922(g)(1) ..."), amended on denial of reh'g, 20 F.3d 365 (9th Cir.1994). The details of the defendant's prior crime do not make it "more probable or less probable" that the defendant is a convicted felon. See Fed.R.Evid. 401. Rather, this information tends