Full opinion text
FRANK M. JOHNSON, Jr., Circuit Judge: Appellants were members of a marijuana smuggling organization which called itself the “Black Tuna” enterprise. The Black Tuna group imported on a massive scale. According to statements by one appellant, during the period from October 1976 to shortly after September 1977, one of the four years covered by the indictment, the Black Tuna group successfully imported into the United States over one million pounds of marijuana. Twelve defendants were charged in a one-hundred page superseding indictment containing thirty-six counts. The superseding indictment covered the period from August 1974 to April 1978. Following a lengthy jury trial appellants were convicted of violating the racketeering statute, 18 U.S.C.A. § 1962(c) and (d); the travel act, 18 U.S.C.A. § 1952; and federal drug laws, 21 U.S.C.A. §§ 841(a)(1), 843(b), 848, 952, and 963. Four of the appellants were acquitted on some of the counts charged against them. Appellants received substantial sentences. The trial in this case was extraordinary in several respects. Because of the extent of Black Tuna’s importation and distribution of marijuana, the trial, which lasted from September 1979 to February 1980, received extensive publicity. The publicity was intensified on December 6 when the Government announced that two separate indictments were to be returned that day: one against appellant Fisher for bribing a juror, and another against several of the defendants charging them with conspiracy to obstruct justice. The obstruction of justice indictment alleged that those charged had plotted to disrupt the proceedings and to assassinate the trial judge. The trial court then sequestered the jury during the week of December 6-13, 1979. The trial court also found it necessary to substitute three alternate jurors for regular jurors. First, the juror who was implicated in the bribery charge was replaced. Another regular juror was later replaced by a substitute juror after she revealed that she had inadvertently learned that an indictment had been returned against a juror. Finally, after the jury had been deliberating for a day and a half, one juror suffered a heart attack. The trial court, over defense objections, substituted an alternate after receiving assurances from the jurors who had deliberated that they could and would erase from their minds their past deliberations and start anew. Appellants raise numerous contentions on appeal. After careful examination of each of these arguments, we conclude that all of appellants’ convictions should be affirmed, except for Eehezarreta’s racketeering con- • viction. I. THE BLACK TUNA ENTERPRISE In August 1974 Lucas McLeod arranged with appellant Platshorn to ship a load of marijuana from Florida, where they resided, to appellant Meinster in Philadelphia, where he operated two dress shops which he used as fronts for his marijuana dealing. In October 1974 McLeod had 2000 pounds of marijuana trucked to Meinster in Philadelphia. One of McLeod’s employees, a podiatrist named Dr. Morris Keller, was the truck driver on that occasion. Keller was also a government witness at trial. Meinster paid McLeod approximately $700,000 in installments. McLeod did not pay a brokerage fee to Platshorn because Platshorn disclosed that he was Meinster’s partner. McLeod later delivered two additional loads of marijuana, one of 2000 and another of 4000 pounds at $275 per pound, to Meinster in Philadelphia. McLeod informed Platshorn of the size of each of those shipments to Meinster. After the third delivery to Philadelphia, Platshorn instructed McLeod to deliver future shipments to Platshorn’s residence in Miami. Two such deliveries, one of 2000 and another of 3000 pounds, were made in 1975 although Platshom rejected the second delivery because he believed the marijuana to be of inferior quality. The source of McLeod’s marijuana was co-conspirator Raul Davila, a Colombian resident. Platshorn later acquired marijuana from sources other than McLeod; among them were members of the Miami Cuban community. In the late spring of 1976 Platshorn leased property in Miami for the purported purpose of operating an automobile auction business. The auction was in fact intended to be a cover for the marijuana importation and distribution activities of Meinster, Platshorn and others. The auction business constantly lost money — up to $4000 weekly. Keller was hired to work at the auction, ostensibly as a general manager. Keller’s actual primary responsibility was to supervise the loading of the marijuana that was stored at the auction site into customers’ vehicles parked at the auction or on occasion at Platshorn’s residence. Marijuana was also placed in vehicles that were delivered to customers; one such customer was appellant Myers. In June 1976 Platshorn hired Raymond Jiminez as the comptroller for the auction. Jiminez was a central government witness at trial. Numerous marijuana transactions were completed in Platshorn’s office at the auction. Jiminez became acquainted with a number of persons, including appellants Myers and Echezarreta, who came to the auction to engage in marijuana transactions. By mid-1976 Platshorn and Meinster had a flourishing importation and distribution business. Appellant Fisher worked as a pilot for vessels which offloaded marijuana from mother ships on the high seas and delivered it to American shores. Fisher allegedly received $100,000 for each such pilotage effort made for the Platshorn-Meinster enterprise. Appellant Grant worked for Platshorn and Meinster as a security chief in charge of protecting the cargos of marijuana. Most of the enterprise’s marijuana, until the summer of 1976, was obtained from a Latin-American organization based in Miami. In the fall of 1976 Platshorn went to Colombia and personally arranged with Davila to import marijuana directly from Colombia. The cost for obtaining the marijuana was approximately $60 per pound. The first shipment, totalling 1100 pounds, was delivered directly from Davila to the auction in the fall of 1976. Delivery preceded Platshorn’s return from Colombia; after Meinster forwarded payment for the shipment, Platshorn was able to leave Colombia. Davila and the others used the code phrase “Black Tuna,” spoken in English or Spanish, as the signal for arriving aircraft in Colombia or for vessels rendezvousing with Davila’s cargo ships on the high seas. Davila himself was referred to as the Black Tuna and eventually the enterprise came to be known as Black Tuna. Platshorn even distributed to the organization’s members a medallion in the form of a dark-colored fish, worn around the neck. The initial 1100-pound shipment was only a portion of the shipment that Davila had set aside for the Black Tuna organization. Platshorn, Myers, Keller and others arranged to send a plane to Colombia for the balance of the marijuana. Myers offered to furnish manpower to unload the plane after it landed at the Punta Gorda Airport near Fort Myers, Florida. Myers also indicated •that for a payment of $10,000 he could keep the airport manager away while the unloading took place. By happenstance, the airport manager was not on duty when the plane arrived. Myers also stated that he wished to purchase any marijuana exceeding the amount designated for a particular customer. The plane landed on November 5, 1976; Keller supervised the successful unloading of approximately 3800 pounds of marijuana. The plane was abandoned because of engine trouble and was discovered the following day by law enforcement officers. Meinster moved to Miami in early 1977. The enterprise at that time owned several yacht-sized vessels and operated out of several locations, including a suite in the Fontainebleau Hotel. In January 1977 Jiminez went to that suite to deliver a car to Myers. Upon entering the suite Jiminez saw Plats-horn, Meinster, Myers, and other Black Tuna members. Large stacks of money covered a table. After asking Jiminez whether he had ever seen so much money, Myers remarked that “It is not all ours yet, so don’t worry about it.” The Black Tuna members apparently did not hesitate to fully avail themselves of the Fontainebleau’s room service; Jiminez testified that Plats-horn told him that the room service bill from October 1976 to April 1977 was $66,-000. The enterprise used several vessels for offloading marijuana and could recycle vessels after their use because co-defendant Phillips sold boats in Fort Lauderdale. The enterprise used luxury craft rather than shrimping trawlers or other such vessels in order to attract less suspicion. The Fontainebleau suite was the Black Tuna headquarters until March 1977. In April 1977 Platshorn obtained a houseboat, called BEAM’S POST TIME, which was moved into waters adjacent to the Fontainebleau, where it became the new headquarters, complete with a phone line hookup with calls being handled through the Fontainebleau’s main switchboard. Platshorn, Meinster and Myers also obtained interests in or established other businesses, one of which was Land-Air which leased a private airstrip at the St. Petersburg-Clearwater Airport. Two of the planes kept on that airstrip belonged to Platshorn and Meinster. Myers was in charge of the Land-Air venture, which served as a cover for Black Tuna pilots. In February 1977 Platshorn asked a real estate agent, Lawrence Richter, to locate waterfront homes or warehouses that could serve as “stash houses.” That same month a suitable house, with direct ocean access, garage facilities and no close neighbors, was located on San Marino Drive and was leased under a fictitious name. The house was used successfully several times for shipments of marijuana imported by Fisher. In April 1977 Fisher made another delivery to the house but one of the Black Tuna members rejected the marijuana as inferior. Platshorn directed Echezarreta, the broker of the transaction, to remove the marijuana within 24 hours. Grant was to provide security until Echezarreta could locate another buyer. That same day the owner of the house telephoned Richter and informed him that she was sending a carpenter to the house. Richter in turn informed Platshorn and then went to the house where he saw marijuana stacked almost to the ceiling in the living room. Richter, at Platshorn’s direction, prevented the carpenter from entering the house. That same evening, while Jiminez and Myers were aboard the BEAM’S POST TIME, Myers received a number of phone calls. They went to the Fontainebleau Hotel. At 10:30 p. m. Myers had a phone conversation after which he told Jiminez that he had just advised Meinster that everything was secure at the San Marino house. San Marino was not secure for long, however. About 11:30 p. m. a suspicious neighbor called the police after observing cars and a large truck arrive at the San Marino house. Echezarreta had located a buyer for part of the marijuana, who decided to take possession at night rather than to heed Platshorn’s advice to remove the marijuana during late-afternoon rush-hour time when less attention would be attracted to the loading. Upon their arrival at the house, police officers saw bundles of marijuana in the truck which was parked in the driveway and smelled marijuana from within the house. The police entered the house, arrested the occupants who had not fled, and seized 16,000 pounds of marijuana. Grant and Echezarreta escaped arrest but one of Grant’s associates named Verdi did not. The next day Jiminez obtained a list of the persons arrested and phoned Meinster, who told him to obtain Verdi’s release on bond because he was Grant’s assistant. Because of the presence of law enforcement officers at the marina where the yacht used by Fisher to deliver the marijuana to the San Marino house was being kept, Platshom allegedly sank the yacht. The Black Tuna enterprise remained intact after the San Marino setback. In May 1977 Platshorn obtained a new waterfront property suitable for smuggling. Platshorn told Jiminez while showing him the house in June that he had used that house for storing marijuana and that 20,000 pounds had been moved in and out of the house in less than ten days. Jiminez at that time observed five or six boxes which Platshorn described as the remains of the 20,000 pound operation. Other businesses collateral to the Black Tuna marijuana enterprise were planned or established. One such business was formed in order to send cars to Davila in Colombia; a Cadillac was sent in July 1977. In December 1977 Myers asked Jiminez if he could obtain a mortgage under fictitious names for certain property to be used for growing marijuana. That proposed deal was to be handled by the Green Turtle Construction Company. In July 1977 co-defendant Phillips invited a friend from North Carolina, George Purvis, to meet with Platshorn in Florida. Upon meeting Purvis, Platshorn revealed that he planned to import 40,000 pounds of marijuana on Labor Day and that he preferred to import into North Carolina rather than into Florida. Purvis agreed to find a suitable location. When he returned to North Carolina, Purvis was informed that the vessel to be used by the Black Tuna organization was the PRESIDENTIAL, an 85-foot yacht that Platshorn had purchased from Phillips for $250,000 in cash. Purvis obtained North Carolina registration papers in a fictitious name for the PRESIDENTIAL and sent the papers to Phillips. Phillips revealed to Purvis that the Black Tuna organization had an income of about $12,-000,000 the previous year, that it owned five vessels, and that it was capable of monitoring Drug Enforcement Administration broadcasts. In late August Platshorn and Phillips met Purvis in North Carolina and selected a landing site from the alternative sites that had been chosen by Purvis. Platshorn confirmed Phillips’ statement regarding earnings of $12,000,000 the past year from the smuggling operation. Purvis obtained trucks and workers for the offloading. Myers organized the crew for the voyage of the yacht the PRESIDENTIAL, which was his first transaction as a full partner in the Black Tuna organization. Fisher and Echezarreta had each refused to serve as captain of the vessel. After taking on 36,-000 pounds of marijuana on the high seas, the PRESIDENTIAL went aground near Great Abaco Island in the Bahamas. Water had entered a porthole that had been opened by a crew member who had overindulged in his use of cocaine, and the bilge pumps had failed to work. Black Tuna members made several efforts to retrieve the - marijuana from the PRESIDENTIAL. Grant flew to Abaco intending to drop a new bilge pump, but he was unable to make the drop. Fisher was dispatched aboard the BIG GLO II with directions from Platshorn to recover as much marijuana as possible from the PRESIDENTIAL. Fisher removed several bales in one attempt. In a later attempt on September 3, Fisher and two accomplices were foiled by four Bahamian police officers who were concealed inside the PRESIDENTIAL. Fisher and his accomplices returned to the BIG GLO II, which later struck a reef as it fled. Its crew was seen discarding bales into the water. Fisher later told Jiminez that he had rescued two bales and showed him some marijuana which he said came from those two bales. The Black Tuna organization lost $1 million in the PRESIDENTIAL incident. A search of the PRESIDENTIAL revealed 745 bales of marijuana, a receipt for the BIG GLO II, and papers relating to the Green Turtle Construction Company. In September 1977 Meinster and Purvis made plans to deliver marijuana from Davila’s vessel, the mothership DON ELIAS, to North Carolina. Purvis contacted Wade Bailey, captain of the OSSPREY, about obtaining a vessel for performing the transfer from the DON ELIAS on the high seas. Bailey was a confidential informant for the government. Purvis suspected that Bailey was an informant but needed the OSSPREY because Purvis’ own vessel had been damaged on a trial run in preparation for the importation via the DON ELIAS. Meinster advised Purvis to double Bailey’s payment to $100,000, believing that the government could not meet that price. Grant had another suggestion: “shoot him.” Grant rented a building for storage of the marijuana. After the OSSPREY took on a cargo of marijuana from the DON ELIAS on the high seas, the DON ELIAS was seized by federal authorities. Purvis’ associates were arrested but Purvis fled to Florida where he lived for a time on the BEAM’S POST TIME. As the result of a drug deal arranged by Jiminez, in which Echezarreta was the broker, a financial dispute between Echezarreta and some of his Colombian clients arose. Myers informed Jiminez that he had learned of a “rip-off” in the deal and that Echezarreta would be required to answer to certain Colombians for the loss. As a result of the incident Platshorn and Myers stopped speaking to each other for a time. Also, Platshorn criticized Echezarreta concerning the deal. Shortly thereafter Platshorn fired Jiminez as comptroller of the auto auction and Jiminez went to work for Myers in his lobster business on the west coast of Florida. Myers’ active participation in the Black Tuna organization diminished although he continued to operate Land-Air. Additionally, in December 1977 Myers succeeded in resolving the financial dispute between Echezarreta and the Colombians. On January 2, 1978, a courier of a smuggler from Tampa who had just imported 40,000 pounds of marijuana came to Platshom’s house with a sample, a 50-pound bag. Platshorn and Purvis inspected and sampled the marijuana. Platshorn found it to be acceptable in quality and purchased that bag but declined to buy the remainder of the load because he felt that he had been insulted by the courier’s demand for immediate payment. In January 1978 Grant, Purvis and Plats-horn arranged several unsuccessful attempts to import marijuana directly from Davila in Colombia. On one occasion Purvis and two crew members flew to Colombia where they contacted Davila. After Purvis returned from Colombia he surrendered to federal authorities and thereafter agreed to cooperate with DEA agents. Purvis then went to work at the auction. In March 1978 Purvis again flew to Colombia to retrieve two Black Tuna pilots who had been ransomed from the army by Davila. The numerous issues presented upon this appeal will be discussed in what we consider to be an orderly sequence. II. REPLACEMENT OF A JUROR AFTER DELIBERATIONS BEGAN After giving the instructions to the jury, the trial court discussed with counsel procedural options in the event that a juror became incapacitated after deliberations had begun. Defense counsel unanimously stated that they would refuse to stipulate to a jury of less than twelve. See Fed.R. Crim.P. 23(b). They also objected to a proposal that an alternate juror might be impaneled if a regular juror became unable to continue. Despite defense objection, the court ordered that the remaining alternate juror, Mr. Lewis, not be dismissed but rather that he be separately sequestered while the regular jurors deliberated. Lewis was directed not to watch television newscasts. The jury began deliberations on a Friday and deliberated from 9:30 a. m. until 4:30 p. m. The following day the jurors deliberated from 9:30 a. m. until approximately 2:30 p. m., when they asked to return to the hotel because one juror, Mr. Zalc, felt ill. At one point during the jury’s deliberations the foreman requested that some trial testimony be made available to the jury. Before the court had decided whether to allow the jury to review the requested testimony, the foreman indicated that several jurors recalled several incidents which helped them remember the requested testimony and stated that “this probably will make us look at other testimony with a greater insight.” Mr. Zalc was hospitalized on Sunday and on Monday suffered a heart attack. The court thus found it necessary to excuse Zalc from further jury service. On Tuesday the court decided to replace Zalc with Lewis. Before the court decided to impanel Lewis, it questioned Lewis and the remaining jurors. The court first questioned Lewis and received his assurances that he had neither discussed the case with anyone nor received any extrinsic information about it. Lewis also assured the court that he would have no difficulty working with the other jurors from> a clean slate. The court summoned the other jurors to the courtroom, informed them of the events, and ordered that all materials upon which they had written during deliberations be confiscated. The court then sent the jury out of the courtroom and ordered that the jurors return individually for questioning. Although the court did not ask the jurors whether they had either personally or collectively arrived at opinions or conclusions about any of the charges or defendants, the court did ask each juror whether he or she could and would wipe from his or her mind the deliberations of the two previous days and start fresh and anew. Each juror gave the court that assurance. The court then instructed the jury on its duty to start its deliberations anew. After Lewis was impaneled a foreman was again elected and the jury deliberated for six days until reaching a verdict. Appellants urge that the action of the trial court in impaneling an alternate after jury deliberations had begun was reversible error. They object to the action on both constitutional grounds, as violative of their right to a trial by a fair and impartial jury under the Sixth Amendment, and statutory grounds, as violative of Fed.R. Crim.P. 24(c). Initially, we agree with the Government’s position that the language of Rule 24(c) concerning substitution of alternate jurors prior to the jury’s retirement is not constitutionally mandated. See Henderson v. Lane, 613 F.2d 175, 179 (7th Cir.), cert. denied, 446 U.S. 986, 100 S.Ct. 2971, 64 L.Ed.2d 844 (1980) (state trial court substi tution of alternate juror after regular juror suffered heart attack held not to violate defendant’s right to trial by jury under Sixth and Fourteenth Amendments). Cf. People v. Collins, 17 Cal.3d 687, 552 P.2d 742, 131 Cal.Rptr. 782 (1976), cert. denied, 429 U.S. 1077, 97 S.Ct. 820, 50 L.Ed.2d 796 (1977) (substitution of alternate juror after jury deliberations have begun permissible under California constitution); but cf. People v. Ryan, 19 N.Y.2d 100, 224 N.E.2d 710, 278 N.Y.S.2d 199 (1966) (New York constitution prohibits substitution of alternate after jury deliberations have begun. See also United States v. Evans, 635 F.2d 1124 (4th Cir. 1980) (no fundamental unfairness in replacing regular juror with alternate after jury deliberations had begun where defendant agreed to such replacement). The California Supreme Court held, with reference to its own state constitution, that “the right to trial by jury does not require a declaration of a mistrial when a properly qualified alternate juror is available and that juror fully participates in all of the deliberations which lead to a verdict.” People v. Collins, supra, 131 Cal.Rptr. at 786, 552 P.2d at 746. The court found no constitutional objection to substitution of an alternate after deliberations have begun where good cause has been shown for the dismissal and the jury has been instructed to begin its deliberations anew. Id. We believe that such reasoning is applicable to the federal Constitution and disposes of appellants’ constitutional argument. Appellants’ second challenge to the substitution of the alternate after deliberations had begun is based on Fed.R.Crim.P. 24(c), which provides in pertinent part: Alternate jurors in the order in which they are called shall replace jurors who, prior to the time the jury retires to consider its verdict, become or are found to be unable or disqualified to perform their duties .... An alternate juror who does not replace a regular juror shall be discharged after the jury retires to consider its verdict. Appellants urge that the district court’s substitution of the alternate, in violation of the language of Rule 24(c), is reversible error. In evaluating appellants’ argument we are guided by the Supreme Court’s statement in Fallen v. United States, 378 U.S. 139, 142, 84 S.Ct. 1689, 1691, 12 L.Ed.2d 760 (1964), that the Federal Rules of Criminal Procedure “are not, and were not intended to be, a rigid code to have an inflexible meaning irrespective of the circumstances.” See United States v. Mendoza, 565 F.2d 1285, 1289 (5th Cir.), rehearing en banc, 581 F.2d 89 (5th Cir. 1978) (adopting relevant portion of panel decision). The question before this Court is whether the appellants were prejudiced by the substitution of the alternate after jury deliberations had begun. We conclude that they were not because the procedural precautions taken by the trial court obviated the danger of prejudice to the appellants and overcame the concerns of the draftsmen of Rule 24(c). The present language of Rule 24(c) is little changed from a preliminary draft prepared in February 1944. 3 L. Orfield, Criminal Procedure Under the Federal Rules 94 (1966). The draftsmen had previously considered and discussed the restriction against substituting an alternate once deliberations have begun. Id. at 94, 98; Orfield, Trial Jurors in Federal Criminal Cases, 29 F.R.D. 43, 46, 53 (1961). A preliminary draft dated May 1942, which contained a proposed rule that would have allowed substitution of an alternate juror after the jury retired for deliberations, was submitted to the Supreme Court for comment. The Court queried the rules committee whether the committee had satisfied itself that such a procedure would be desirable or constitutional. Orfield, Trial Jurors in Federal Criminal Cases, supra, 29 F.R.D. at 46. The draftsmen of the rules committee did not adopt that proposed rule. It was feared that if such substitutions were permitted “[t]he members of the regular jury might bring such influence on a dissenter as to disable him and then require an alternate. The alternate may have been exposed to improper influences before he takes part as he does not previously sit in the jury room.” 3 Orfield, Criminal Procedure Under the Federal Rules, supra, at 94. In addition to those proposals presented to the draftsmen of Rule 24(c) which would have permitted substitution of alternates during deliberations, subsequent proposals have been made that Rule 24(c) be amended to permit such substitutions. Supplemental Report of Committee on Federal Rules of Civil Procedure — Judicial Conference— Ninth Circuit, 37 F.R.D. 71, 74 (1965) (advocating substitution of alternates in protracted trials after case submitted to jury); Preliminary Draft of Proposed Amendments to the Federal Rules of Criminal Procedure, Committee on Rules of Practice and Procedure of the Judicial Conference of the United States (1973) (quoted in United States v. Lamb, 529 F.2d 1153, 1162 n.7 (9th Cir. 1975) (dissenting opinion)) (advocating substitution of alternate after deliberations have begun; would also require that “the court shall advise the entire jury that all facts shall be reviewed and discussed with the juror who has previously served as an alternate juror”); Paisley, The Federal Rule on Alternate Jurors, 51 A.B.A.J. 1044 (1965). Some states have adopted statutory criminal rules provisions allowing substitution of an alternate juror after deliberations have begun. E. g., Cal.Pen. Code § 1089 (West); see Paisley, The Federal Rule on Alternate Jurors, supra, 51 A.B.A.J. at 1045. See generally Annot., 84 A.L.R.2d 1288 (1962). However, the American Bar Association Project on Minimum Standards for Criminal Justice, Standards Relating to Trial by Jury § 2.7 (Approved Draft 1968), rejected such substitution provisions. The ABA Advisory Committee on the Criminal Trial believed that it was undesirable to substitute a juror who had not had the benefit of prior deliberations. Id. § 2.7 at 83. The initial decision by the district court in this case not to discharge the alternate Lewis when the jury retired was a violation of the language of Rule 24(c) which provides that an alternate who does not replace a regular juror shall be discharged after the jury retires to deliberate. This Court, however, does not apply a per se rule of reversal to Rule 24(c) violations. United States v. Allison, 481 F.2d 468, 472 (5th Cir.), aff’d after remand, 487 F.2d 339 (5th Cir. 1973), cert. denied, 416 U.S. 982, 94 S.Ct. 2383, 40 L.Ed.2d 759 (1974); accord, United States v. Hayutin, supra, 398 F.2d at 950. Admittedly, that provision of Rule 24(c) has been held by this Circuit to be “a mandatory requirement that should be scrupulously followed.” United States v. Allison, supra, 481 F.2d at 472; accord, United States v. Hayutin, supra, 398 F.2d at 950; United States v. Lamb, supra, 529 F.2d at 1156. Despite the mandatory language of Rule 24(c), however, this Court in United States v. Allison, refused to hold that any departure from the rule automatically required a new trial. The Court held that a new trial would not be required unless there was a reasonable possibility that the presence of the alternate affected the jury’s verdict. 481 F.2d at 472. In Allison the trial court did not discharge an alternate juror when the jury retired, but rather permitted the juror to sit in the deliberation room with the regular jurors although he was directed not to participate in any way. This Court remanded the case for an evidentiary hearing on the possibility that the jury’s verdict was affected. The district court’s subsequent finding was affirmed on appeal. 487 F.2d 339. Other technical violations of Rule 24(c) have been held not to be reversible error. In United States v. Cohen, 530 F.2d 43, 48 (5th Cir.), cert. denied, 429 U.S. 855, 97 S.Ct. 149, 50 L.Ed.2d 130 (1976), this Court sanctioned the replacement of a regular juror by an alternate after the jury had been ordered to retire for deliberations, but before actual deliberations had commenced. Replacement of a disabled juror after deliberations have begun has been approved if the defendant stipulates to such substitution. United States v. Evans, supra, 635 F.2d 1124; Leser v. United States, 358 F.2d 313, 317 (9th Cir.), petition for cert, dismissed, 385 U.S. 802, 87 S.Ct. 10, 17 L.Ed.2d 49 (1966). Failure to discharge alternate jurors, if the alternates had been separated from the jury while deliberating and at no time had been in contact with the deliberating jury, has been held not to be prejudicial, reversible error under Rule 24(c). United States v. Hayutin, supra, 398 F.2d 944. Appellants rely upon United States v. Lamb, supra, 529 F.2d 1153, in which the Ninth Circuit, sitting en banc, reversed a conviction on the ground that the district court failed to comply with the plain requirements of Rule 24(c). Lamb, however, is clearly factually distinguishable from the present case. The trial court in Lamb initially directed an alternate to “stand by” in case she was needed, but then discharged her when the jury returned a verdict of guilty after four hours of deliberation. The court, however, refused the verdict because it was inconsistent with the instructions. The court recalled the alternate and impaneled her in the place of another juror who had requested to be excused. The court then- reinstructed the jury and told it to begin its deliberations anew. The newly constituted jury returned a guilty verdict after only twenty-nine minutes of deliberation. After the final verdict was returned, the court sought and received assurances from the jury foreman and the alternate who had been substituted that the jury had begun deliberations anew and had discussed all the points of evidence. Id. at 1158. The brief amount of time in which the second verdict was reached demonstrated to the appellate court that the alternate was impermissibly coerced and that the newly constituted jury did not give conscientious, careful reconsideration to the case despite the trial court’s instruction that it begin anew. Id. at 1156. However, the Lamb court’s reversal of the conviction was apparently based on the mere fact that the mandatory provision of Rule 24(c) was violated; the court stated that the length of deliberation by the newly constituted jury was “essentially irrelevant.” Id. at 1156 n.7. The Ninth Circuit noted, some of the reasons underlying Rule 24(c), most significantly the “inherent coercive effect” upon an alternate who joins a jury after it has deliberated for some length of time and the possibility that a juror who disagreed with the other jurors might be coerced into feigning incapacity to continue sitting on the jury. Id. at 1156. The dissenting opinion in Lamb criticized the majority’s adoption of a per se rule of reversal and asserted that a determination should be made as to whether violation of the rule was prejudicial to the defendant, citing this Court’s decision in United States v. Allison, supra, 481 F.2d at 472, and United States v. Hayutin, supra, 398 F.2d at 950-51. Id. at 1159. The Lamb dissent would not, however, have remanded the case for an evidentiary hearing on the possibility of prejudice, as this Court did in Allison, because the district court had already made the necessary fact finding on the issue of possible prejudice. Id. at 1161. The dissent also stated that there is greater justification for a rule of reversal per se if an alternate is present with the jury during deliberations, since the privacy of jury deliberations is thereby violated, than for such a rule when an alternate is substituted after deliberations have commenced. Id. at 1160, citing Leser v. United States, supra, 358 F.2d at 318. The most substantial concern about substitution of an alternate juror after deliberations have begun is that the alternate might be coerced by jury members who might have already formulated positions or viewpoints or opinions. Here, the trial court after careful consideration utilized a number of procedural mechanisms in order to protect the appellants’ rights. The court sequestered the alternate during the preliminary jury deliberations, carefully questioned each juror individually about whether he or she could and would start the deliberations anew, and pointedly instructed the jury to begin its deliberations anew. These extreme precautions, in addition to the continuation of deliberations for an entire week after the alternate was impaneled, negated any possible coercive effect or any undue influence. The safeguards utilized by the court neutralized the possible prejudice to the appellants. We need not remand for an evidentiary hearing on the issue of prejudice, see United States v. Allison, supra, 481 F.2d at 472, because we conclude that the instructions to the jury to begin anew, the jurors’ individual assurances that they could in fact begin anew, and the full participation of the substituted alternate in the deliberations, which lasted six days, obviated the danger of undue prejudice. On the record before us we cannot discern that appellants were prejudiced by the substitution. The substitution procedure utilized by the court did not deprive appellants of their right to a full consideration of their cases by an impartial jury panel. We emphasize that the court’s decision to substitute the alternate was made in the context of a most complex and protracted trial, lasting over four months, of multiple defendants on numerous substantive and conspiracy charges. Our conclusion that the district court committed no reversible error must likewise be understood as limited to such an exceptional context. We have considered the relief sought by the appellants — a new trial — in light of the purpose of the federal rules of criminal procedure: “to secure simplicity in procedure, fairness in administration and the elimination of unjustifiable expense and delay.” Fed.R.Crim.P. 2. The district court’s substitution procedure secured a just and nonprejudicial result and served to further the purpose of the federal rules of criminal procedure and the administration of justice. III. OTHER JURY-RELATED ISSUES On December 6, 1979, the Government moved to sequester the jury because two indictments charging obstruction of justice were to be returned that day against some of the defendants. Appellant Fisher was charged with offering a bribe to a juror. That juror was also indicted as a result of the alleged bribery by Fisher. Other defendants were separately charged with conspiracy to obstruct justice in an indictment which alleged, inter alia, the existence of a plot to disrupt the trial proceedings by killing the trial judge. The trial court ordered the jury temporarily sequestered but did not inform the jury of the reason for the sequestration. The court denied Meinster’s counsel’s motion to sequester the jury for the remainder of the trial. The following day, after a hearing, the court granted the Government’s motions to discharge the juror who was the object of the attempted bribe and to revoke the appearance bonds of certain defendants. The court denied motions by Meinster’s counsel to declare a mistrial or to conduct an individual voir dire of the jurors. The court had previously denied Meinster’s motion, because of anticipated extended and intense publicity, to exclude the public from the hearing on the Government’s motions. Approximately one week later, on December 13, the court, over defense objections, released the jury from sequestration. The court explained to the jury that the reason for the sequestration was to avoid exposing them to certain publicity about matters occurring in the trial out of their presence. From the outset of the trial the court had repeatedly admonished the jury against exposure to media reports of the trial. In discussing with the jurors their release from sequestration, the court asked them whether they had heeded its repeated instruction not to discuss the case among themselves or with anyone else. The jurors nodded affirmatively. The court then asked the jurors for a “solemn pledge” that they would not watch any televised news, listen to the radio, or read the newspaper; each juror gave that pledge. Four days after the jury was released from sequestration one of the alternate jurors was discharged after she informed the court that she had inadvertently learned from a co-worker of an indictment against a juror. She told the court that she had not communicated this information to any other jurors. The court asked the remaining jurors collectively whether any of them had learned of any events occurring during the sequestration period or whether anyone had talked to them about the trial. The jurors responded negatively. The court denied Meinster’s counsel’s request for an individual voir dire of the jurors. During the remainder of the trial the court continued to seek and receive assurances from the jurors that they had not been exposed to extrinsic information about the case. A. Release of the Jury from Sequestration; Voir Dire of the Jury Appellants contend that the court’s release of the jury from sequestration in the midst of considerable local media coverage concerning the trial denied them a fair trial by an impartial jury unaffected by prejudicial publicity. They also maintain that the general or collective voir dire was inadequate. Before a reversal will lie on the ground that the district court erred in releasing the jury from sequestration, appellants must demonstrate a substantial likelihood that some prejudice did result. United States v. Harris, 458 F.2d 670, 675 (5th Cir.), cert. denied, 409 U.S. 888,93 S.Ct. 195, 34 L.Ed.2d 145 (1972). See United States v. Arciniega, 574 F.2d 931, 933 (7th Cir.), cert. denied, 437 U.S. 908, 98 S.Ct. 3101, 57 L.Ed.2d 1140 (1978) (“[T]he decision to allow a jury to separate rests within the sound discretion of the district court, and . . . for separation to constitute reversible error there must be an objection supported by specific reasons against separation and a showing that the defendant was actually prejudiced by reason of the separation.”). The trial court has the discretion to decide whether to allow the jury to separate. Harris, supra, 458 F.2d at 674-75. Whether the trial court admonished the jury to avoid outside influence is a significant factor in determining the likelihood of prejudice. The trial court in this case instructed the jury throughout the trial to avoid exposure to media reports of the trial. The jurors collectively assured the court, both when they were released from sequestration and on subsequent trial days, that they had received no outside information about the case. The court’s constant admonitions to the jury concerning media coverage and its collective questioning of the jury were adequate safeguards to ensure that appellants received a fair trial free from prejudice. United States v. Capo, 595 F.2d 1086, 1093 (5th Cir. 1979), cert. denied, 444 U.S. 1012, 100 S.Ct. 660, 62 L.Ed.2d 641 (1980); United States v. Herring, 568 F.2d 1099 (5th Cir. 1978). An individual, rather than a collective, voir dire concerning the jurors’ exposure to publicity occurring during the trial is not required in all cases. United States v. Capo, supra, 595 F.2d at 1093. Whether individual examination of the jurors is warranted depends on a two-step threshold determination by the court: first, whether the material disseminated during the trial is beyond the record and is seriously prejudicial in content and, second, whether there is a likelihood that the material reached the jury. Id. The jurors’ negative responses to the collective inquiry in this case adequately demonstrated that none of the jurors was exposed to extrinsic information. See id. We do not commend the trial court’s decision to end the sequestration, amidst considerable publicity, after only one week. Indeed, many of the problems at trial, not only the possibility that the extensive prejudicial publicity would come to the attention of the jurors but also the problem of the tampered-with juror, could have been eliminated had the court sequestered the jury from the beginning of the trial. Nevertheless, we do not conclude that the trial court’s actions constituted prejudicial, reversible error. B. Allegation of a Contaminated Jury In a tape-recorded conversation between Fisher and a government agent, Fisher, who was charged with bribing a juror, claimed that the bribed juror had discussed the case with other jurors. Fisher, in that recorded conversation, however, stated that the bribed juror had not mentioned the bribe to the other jurors. The trial court determined that no other jurors were affected or tainted. After the court held an evidentiary hearing on the alleged bribery of the juror, it discharged that juror. Additionally, when the court released the jurors from sequestration, it asked the jurors collectively whether they had discussed the case among themselves. They responded negatively. Appellants accuse the court of selective belief, i. e., of believing Fisher’s statement that a juror was bribed, but not believing his statement that the bribed juror had discussed the case with the other jurors. They also urge that the court committed reversible error by failing to voir dire the remaining jurors at the time the bribed juror was discharged. Appellants claim that the trial court’s conclusion that no other jurors were tainted by the bribed juror is not supported by the record. The Government responds that given the extent to which the bribery plot was infiltrated by government agents it is beyond doubt that the other jurors were unaffected. The Government also notes that the trial court twice asked the jurors whether they had discussed the case among themselves and that they responded negatively. It is well settled in this Circuit that the procedure to be used in investigating incidents of jury tampering and the decisions whether to hold a hearing and whether to grant a mistrial rest in the sound discretion of the trial court. United States v. Buchanan, 633 F.2d 423, 427 (5th Cir. 1980), cert. denied,-U.S.-, 101 S.Ct. 1984, 68 L.Ed.2d 301 (1981); United States v. Chiantese, 582 F.2d 974, 978 (5th Cir. 1978), cert. denied, 441 U.S. 922, 99 S.Ct. 2030, 60 L.Ed.2d 395 (1979); United States v. Khoury, 539 F.2d 441, 443 (5th Cir. 1976), cert. denied, 429 U.S. 1040, 97 S.Ct. 739, 50 L.Ed.2d 752 (1977); Tillman v. United States, 406 F.2d 930, 937-38 (5th Cir.), vacated on other grounds, 395 U.S. 830, 89 S.Ct. 2143, 23 L.Ed.2d 742 (1969). The trial court retains such discretion even though this Court has required affirmative proof of the harmlessness of private communications outside the jury room. United States v. Khoury, supra, 539 F.2d at 443. When juror misconduct concerns influences from outside sources, the complete failure of the trial court to hold a hearing constitutes an abuse of discretion and is reversible error because a presumption of prejudice arises when the trial court learns of such influences. United States v. Chiantese, supra, 582 F.2d at 979. Any off-the-record contact with a jury is presumptively prejudicial and the Government bears a heavy burden of proving that such a contact did not affect the jury; if the Government cannot meet this burden, a new trial is required. United States v. Forrest, 620 F.2d 446, 457 (5th Cir. 1980). Significantly, this Court has not adopted a rigid per se rule automatically requiring the reversal of a conviction in cases concerning juror misconduct. See United States v. Betner, 489 F.2d 116, 119 (5th Cir. 1974). We do require that the trial court determine whether the jury misconduct occurred and whether or not it was clearly prejudicial. Id.; United States v. McKinney, 429 F.2d 1019, 1026 (5th Cir. 1970). In United States v. Forrest, supra, 620 F.2d 446, a juror was contacted by a relative who sought to influence the juror in defendants’ favor. The juror informed the court that no other jurors were aware of the tampering attempt. However, this Court reasoned that, because that juror would probably claim that she complied with the trial court’s instructions to the jurors not to discuss the case among themselves, only the other jurors could be relied upon to state whether any of them had discussed the case with the tainted juror. Id. at 457. The Court was concerned about the serious questions of prejudice raised by the tampering and the possibility that the tainted juror had commented on the merits of the case in the presence of other jurors. Id. Stating that a party claiming that an improperly influenced jury returned a verdict against him must be given an opportunity to prove that claim, citing Remmer v. United States, 350 U.S. 377, 76 S.Ct. 425, 100 L.Ed. 435 (1956), the Forrest Court remanded the case for a hearing to determine whether the other jurors knew about the tampering or whether any prejudicial material reached the jury. 620 F.2d at 458. The Court directed that on remand the trial court should question the jurors pursuant to the two-step test adopted in United States v. Herring, supra, 568 F.2d 1099. Id. See United States v. Capo, supra, 595 F.2d 1086. The Court held that it could not conclude that a new trial was warranted, citing United States v. Allison, supra, 481 F.2d 468. A new trial would be required, stated the Court, only if it were determined on remand that the jury was contacted impermissibly and that the Government failed to satisfy its burden of proving the contact was not prejudicial. 620 F.2d at 459. The Forrest Court declined to affirm the convictions because the record was silent about what knowledge the other jurors may have had. We have carefully studied the record and conclude that the district court committed no reversible error in the procedure used in determining that no other jurors were “tainted.” After holding a hearing in which it determined that a juror had been tampered with, the court discharged that juror. On that same day the jury began its one-week period of sequestration. Some counsel requested that the court voir dire the other jurors individually to determine the extent of their conversations with the juror who had been removed. However, the court decided to question the jurors collectively or generally because as the court observed it did not want to arouse the suspicions of the jurors about the reason for the removal of the discharged juror. The court stated that it did not want to create the impression that one juror had been removed because someone had contacted her about the case. When the jury was released from sequestration, the court twice asked the jurors collectively whether they had discussed the case among themselves and each time they responded negatively. The court rejected Meinster’s counsel’s suggestion that the jurors be questioned individually. We conclude that the jurors’ collective assurances that they had not discussed the case among themselves were adequate to negate the possibility of prejudice. Because the jurors were questioned by the court concerning their discussions inter se of the case, a remand for the purpose of questioning the jurors, as in United States v. Forrest, supra, is not required. IV. RECUSAL OF THE TRIAL JUDGE Appellants allege that the trial judge’s participation in ex parte proceedings with government attorneys, in which proceedings or meetings the judge was kept informed about a collateral government investigation into alleged plans of certain defendants to disrupt the trial, coupled with certain comments that he made during a mid-trial bond revocation hearing, demonstrated a bias against the defendants. Appellants urge that the judge should therefore have been disqualified from presiding at trial. They assert that the government engaged in overreaching in its collateral investigations of the alleged plans to disrupt the trial and that it impermissibly contacted the trial judge ex parte. They further complain that the trial judge improperly participated in those collateral investigations. Appellants first complain about two episodes of ex parte contacts that occurred early in the proceedings. In the first, pretrial episode government attorneys unconnected to the prosecutors in this case disclosed to the trial judge that a government informant had learned through conversations with Platshorn and Meinster that they planned to obtain false passports and flee the country at the start of trial. The court was also told that the informant had learned that Platshorn and Meinster had plans to eliminate witnesses. The court revoked the appearance bonds of those two appellants. Government attorneys on a separate occasion contacted the trial judge and disclosed that a second government agent had learned from a conversation with Platshorn and Meinster that they had a plan to intimidate or eliminate witnesses. In response to these revelations the court ordered that electronic security screening devices be placed outside the courtroom. Shortly after the bonds of Platshorn and Meinster were revoked, a full adversarial hearing on the revocation order was held. The court made detailed findings and determined that the bond revocations were justified. Meinster and Platshorn then moved for the judge’s recusal on the ground that he had developed a personal bias against them as a result of the ex parte government revelations. The court denied the motion, stating that personal extrajudicial bias could not arise from the proper presentation of evidence in a motion for bond revocation. The third episode of ex parte contacts concerned the alleged conspiracy to obstruct justice. In early November, four weeks before the obstruction indictment was returned, Strike Force attorneys informed the trial judge in his chambers that certain defendants had plotted to disrupt the trial proceedings, intimidate witnesses, and attempt to kill the judge himself. The Strike Force attorneys informed the court about the investigation of the obstruction conspiracy and the court told the attorneys that insofar as it was concerned the government could continue its investigation. After the obstruction of justice indictment was returned on December 6, 1979, the court held a bond revocation hearing and revoked the bonds of Fisher, Grant and Myers, who were still free on bail. Appellants again unsuccessfully filed a motion seeking recusal of the trial judge. Appellants contend that the trial judge allowed his partiality to be seriously questioned by receiving, in ex parte meetings with government attorneys, information concerning the government’s collateral investigation of the alleged plots to disrupt the trial and, further, by sanctioning and participating in those investigations. Appellants maintain that, as a result of the trial judge’s involvement in the investigation, an involvement which they claim demonstrated the judge’s commingling of judicial and prosecutorial roles, the judge should have recused himself. Appellants also charge that recusal of the trial judge was required because several of his comments from the bench demonstrated his bias and prejudice against the defendants. The judge, outside the presence of the jury, made several references to threats against his life and to the thorough security measures that were taken to protect him. Appellants’ attempts to obtain recusal of the trial judge were made pursuant to two statutes which govern recusal of federal district judges on the grounds of bias, prejudice, or lack of impartiality. 28 U.S.C.A. §§ 144 and 455. In Davis v. Board of School Comm’rs of Mobile County, 517 F.2d 1044 (5th Cir. 1975), cert. denied, 425 U.S. 944, 96 S.Ct. 1685, 48 L.Ed.2d 188 (1976), this Court held that the purpose of both disqualification statutes is to guard against personal, extrajudicial bias or the appearance of partiality arising out of such bias. Construing §§ 144 and 455 in pari materia we believe that the test is the same under both. We thus hold that an appellate court, in passing on questions of disqualification of the type here presented, should determine the disqualification on the basis of conduct which shows bias or prejudice or lack of impartiality ... [,] conduct extra-judicial in nature as distinguished from conduct within a judicial context. This means that we give §§ 144 and 455 the same meaning legally for these purposes, whether for purposes of bias and prejudice or when the impartiality of the judge might reasonably be questioned. Id. at 1052, quoted in In re Corrugated Container Antitrust Litigation, 614 F.2d 958, 965 (5th Cir. 1980), cert. denied, 449 U.S. 888, 101 S.Ct. 244, 66 L.Ed.2d 114 (1980). It is well settled that under either Section 144 or Section 455 an allegation of bias sufficient to require disqualification must demonstrate that the bias is personal as distinguished from judicial in nature. The alleged bias and prejudice, in order to be personal and therefore disqualifying, “must stem from an extrajudicial source and result in an opinion on the merits on some basis other than what the judge learned from his participation in the case.” United States v. Grinnell Corp., 384 U.S. 563, 583, 86 S.Ct. 1698, 1710, 16 L.Ed.2d 778 (1966). Thus, a motion for recusal may not ordinarily be predicated upon the judge’s rulings in the same or a related case. An exception to the general rule that the disqualifying bias must stem from extrajudicial sources is the situation in which “such pervasive bias and prejudice is shown by otherwise judicial conduct as would constitute bias against a party.” Davis v. Board of School Comm’rs, supra, 517 F.2d at 1051. Appellants contend that the trial judge was improperly involved in the collateral investigation of the alleged plans to disrupt the trial. We conclude that the judge did not act improperly. The Strike Force attorneys contacted the trial judge in his capacity as presiding judge in those proceedings and the ex parte revelations made by those attorneys were made for two indisputably proper purposes. First, the information conveyed by the attorneys concerning plans by several defendants to disrupt the proceedings was necessary in order to enable the judge to perform his continuing duty to conduct an orderly trial and to take appropriate measures designed to protect the participants therein. Second, the information concerning the plans of certain defendants to flee from the country was highly relevant to the court’s determination on bond revocation. In United States v. Jackson, 430 F.2d 1113 (9th Cir. 1970), the court held that ex parte communication of information concerning threats to witnesses was not a basis for disqualification: The trial judge was informed of the alleged threats to witnesses during his participation in the case because he was presiding over the criminal proceedings lodged against appellants. The fact that the trial judge issued an order revoking appellants’ bail bonds is not a disqualifying fact under these circumstances. United States v. Grinnell Corp., 384 U.S. 563, 86 S.Ct. 1698, 16 L.Ed.2d 778 (1966). Nor is the fact that the trial judge so acted after receiving information from the United States Attorney not made known to appellants in open court. Id. at 1115 (citation and footnote omitted). The trial court in this case was not impermissibly involved in the government’s investigation. Although the court was advised that such an investigation was being undertaken, it did not direct the investigation. Government investigations of possible efforts by criminal defendants to disrupt the judicial proceedings are proper. See Hoffa v. United States, 385 U.S. 293, 87 S.Ct. 408, 17 L.Ed.2d 374 (1966); see also Osborn v. United States, 385 U.S. 323, 87 S.Ct. 429, 17 L.Ed.2d 394 (1966) (judicial approval of use of government informant equipped with concealed recording device to investigate misconduct of defense attorney held constitutional). We turn next to appellants’ contention that several comments of the trial judge reflected his personal bias. Meinster stresses that the judge indiscriminately referred to “the defendants” as attempting to disrupt the trial and destroy the integrity of the jury, without distinguishing between the particular charges against particular defendants. However, the record reveals that the trial judge had been informed, from extensive tape recordings and testimony, of numerous statements made by defendants Myers, Grant, Fisher and Platshorn’s wife to government informants that they had plans to disrupt the trial. The comments made by the trial judge had a judicial, rather than a personal, origin. In United States v. Archbold-Newball, supra, 554 F.2d at 681-82, this Court held that a trial judge’s statement at a bond revocation hearing, based on knowledge acquired in three prior trials, that “these three individuals were members of a conspiracy that I can only describe as a large-scale conspiracy composed of the most vicious individuals that this court has ever seen” was neither personal nor extrajudicial. The comments of the trial judge in the present case were based on information learned in ancillary proceedings which were inseparable from this case, i. e., ex parte meetings in which the judge was warned of threats to disrupt the proceedings and, allegedly, to kill him. The mere fact that some of the remarks made by the judge were not necessary for the resolution of the matter entertained at the hearing at which they were uttered does not convert them into expressions of personal bias. Furthermore, the comments, which were made in a judicial setting and did not stem from an extrajudicial source, do not reflect the “pervasive bias and prejudice” that must be shown in order for a judge to be disqualified for remarks or behavior which takes place in a judicial context. Phillips v. Joint Legislative Comm., supra, 637 F.2d at 1020 n.7; In re Corrugated Container Antitrust Litig