Full opinion text
JERRE S. WILLIAMS, Circuit Judge: Five appellants raise numerous issues challenging their convictions on multiple counts relating to several importations or attempted importations of marihuana and cocaine between June 1984 and August 1985. The original indictment contained twenty-nine counts against twenty-six defendants. Shortly before trial, certain counts were dismissed without prejudice, leaving eighteen remaining counts. The government proceeded against eight of the defendants in a six-week trial that commenced December 1, 1986, and generated some six thousand pages of record and transcript. The eight brought to trial included the appellants, Benjamin Phillip Barrington, Terry B. Drewes, James Ruth Goff, Romu-lo Lon Kuntze, and Horst Schoenhoff. Several of those initially indicted plea bargained and testified for the government: Aura Henriquez de Becerra, David Duke, Robert Finchum, George G. Gantt, Lloyd Wayne Green, Randy Lee Hunt, Alvaro Munoz, and Weldon Eugene Wyatt. We conclude that the prosecutor engaged in some misconduct, and that some of the appellants’ convictions must be reversed for lack of adequately strong supporting evidence. We affirm convictions on the majority of the counts. In addition, we find that two of the conspiracies charged were actually parts of a single, on-going conspiracy; we vacate convictions on the related counts, and remand so that the district court can enter judgment appropriately, as the government may elect. I. FACTS A. Episodes, Counts and Participants Essentially, the government charged some or all of the appellants with involvement in five sets of episodes or activities, three of which gave rise to multiple counts. The five sets were labeled during trial as the Fort Stockton, Tye, Granbury, Maraquita, and Arauca episodes. Fort Stockton: Count 6 (June — October, 1984) Four of the appellants, Barrington, Drewes, Goff, and Kuntze, together with several others, were charged with conspiracy to import more than one kilogram of cocaine from southern Colombia to Fort Stockton, Texas, during the period June through October, 1984, in violation of 21 U.S.C. §§ 952, 960 and 963. According to the government’s theory, Barrington planned the transaction; he and Kuntze would arrange for the pick-up through two Colombians, Munoz and de Becerra. Goff and Drewes would pilot Barrington’s Titan 404 Cessna to Colombia and back to Texas. The load was to be “kicked out” over the Fort Stockton drop site and picked up by a ground crew which included Tom Spratlen and others. Spratlen had long worked for Barrington. He became a government informer early in September, 1984, while the alleged conspiracy was being carried out. Later, he was the government’s principal witness at trial as to this and most of the other counts. Because the southern Colombian pick-up point would have been beyond the range of the Titan 404, the cocaine “stash” was to be moved to a more northerly location. Before the move was accomplished, however, the cocaine was reportedly confiscated by the Colombian army, and the planned importation was cancelled. Tye: Counts 9 through 12 (November— December 3, 1984) According to the government, four of the appellants, along with others, planned and effectuated the importation of nearly 1,000 pounds of marihuana from Belize in November and early December, 1984. Goff was alleged to be in charge of this load, Drewes was his co-pilot and “kicker,” Scho-enhoff was the “contact” with the Belizian source or growers, and Barrington loaned Drewes and Goff a Loran navigational instrument to assist the venture. On December 1, Goff and Drewes flew a Twin Bonanza from Sweetwater, Texas, to Belize and picked up the marihuana. The initial plan was to “kick” the load at a drop site near Fort Stockton. Goff and Drewes, however, decided instead to land at Sweet-water airport, where they brought the airplane into Poe Hangar which had been leased by a co-conspirator. Drewes and others loaded the marihuana from the airplane onto a truck which had been outfitted with a camper shell to conceal its contents. After the loaded truck had been parked at a number of locations it was finally driven to Tye, Texas, where government agents seized 969 pounds of marihuana from the truck. Count 9 charged appellants Barrington, Drewes, Goff, and Schoenhoff, and others, with conspiracy to import approximately 1,000 pounds of marihuana, from Novem-her through December 3, 1984, in violation of 21 U.S.C. §§ 952, 960, and 963. Count 10 charged appellants Barrington, Drewes, Goff, and Schoenhoff, and others, with importing more than 50 kilograms of marihuana on or about December 2, 1984 in violation of 21 U.S.C. §§ 952, 960, and 18 U.S.C. § 2. Count 11 charged appellants Drewes and Goff, and others, with conspiracy to possess with intent to distribute over 50 kilograms of marihuana from November through December 3, 1984, in violation of 21 U.S.C. §§ 841(a)(1) and 846. Count 12 charged appellants Drewes and Goff, and others, with aiding and abetting another individual to possess with intent to distribute approximately 967 pounds of marihuana on or about December 3, 1984, in violation of 21 U.S.C. § 841(a)(1) and 18 U.S.C. § 2. Granbury: Counts H through 21 (November 28, 1984 — January 17, 1985) Here all five appellants were charged with planning to import and actually importing a load of marihuana from Belize to Texas. The government’s theory is that Barrington was in charge of this operation, that Goff and Drewes were the pilots, and that Spratlen along with others were to be the ground crew. The aircraft used was Barrington’s Titan 404. The load of some 45 bags of marihuana was dropped at a site near Pecos, Texas on the night of January 4, 1985. Thirty-eight bags were retrieved by the ground crew, and loaded onto a truck which was driven to Odessa and parked for the night at Spratlen’s motel. The next day as the truck was driven off government narcotics officers followed it to a secluded house at Lake Granbury, Texas. After further surveillance, the officers executed a search warrant on January 6, 1985. They seized 968 pounds of marihuana from the truck and the house. Spratlen testified that after the load had been confiscated Barrington nevertheless insisted that those who had received the marihuana prior to seizure would still have to pay for it. Spratlen also testified that on January 9 or 10, Barrington and Schoen-hoff flew to Las Vegas carrying a total of $660,000. Count H charged the five appellants and others with conspiring to import approximately 1,250 pounds of marihuana from Belize to Texas, between November 28, 1984 and January 17, 1985, in violation of 21 U.S.C. §§ 952, 960 and 963. Count 15 charged that on or about January 4, 1985, appellants Drewes and Goff imported over 50 kilograms of marihuana from Belize to Texas, and that Barrington and Kuntze, along with others, aided and abetted the importation offense, in violation of 21 U.S.C. §§ 952 and 960, and 18 U.S.C. § 2. Count 16 charged Barrington with traveling in interstate commerce to Odessa and then to Dallas, Texas, with intent to distribute the proceeds of an unlawful activity, namely a business enterprise involving marihuana, and related unlawful activities on or about December 16,1984, in violation of 18 U.S.C. § 1952. Count 17 charged Barrington, Drewes, and Goff with traveling in interstate commerce from Sweetwater, Texas, to Missouri with intent to distribute the proceeds of an unlawful activity, namely, a business enterprise involving marihuana, and related unlawful activities, on or about December 21, 1984, in violation of 18 U.S.C. § 1952. Count 18 charged Barrington and Scho-enhoff with traveling in interstate commerce from Fort Worth, Texas to Las Vegas, Nevada, with intent to distribute the proceeds of an unlawful activity, namely, a business enterprise involving marihuana, and related unlawful activities, on or about December 24,1984, in violation of 18 U.S.C. § 1952. Count 20 charged all five appellants and others with conspiring to possess with intent to distribute over 50 kilograms of marihuana from on or about January 3 to January 6, 1985, in violation of 21 U.S.C. §§ 841(a)(1) and 846. Count 21 charged that on or about January 6,1985, other co-conspirators possessed with intent to distribute over 50 kilograms of marihuana, and that all five appellants, along with others, aided and abetted the commission of the possession offense in violation of 21 U.S.C. § 841(a)(1) and 18 U.S.C. § 2. Maraquita: Count 25 (January — July, 1985) The government’s theory as to this episode is that Barrington decided to sell his aircraft and use the proceeds to bring in a big cocaine load from Colombia. The Titan 404 was sold for some $170,000 in late January or early February, 1985. Barring-ton again was alleged to be the principal organizer of the conspiracy. He obtained a Merlin turbo-prop airplane in Oklahoma City. He and Kuntze arranged for a cocaine “source” in Colombia. The plane took off for Colombia on June 24, 1985, from New Orleans, carrying Barrington and a crew of three others who are not involved in this appeal. The Merlin ran low of fuel and landed at Maraquita airport in Colombia on June 24. Barrington and the others were arrested by Colombian authorities and charged with violation of Colombian air space. The Merlin was confiscated by Colombian authorities, but no drugs or other contraband were found on it. Two weeks later, Barrington put up bond and left Colombia. Count 25 charged appellants Barrington and Kuntze, along with others, with conspiracy to import over 50 kilograms of cocaine from Colombia to Texas between January and July, 1985, in violation of 21 U.S.C. §§ 952, 960, and 963. Arauca: Count 27 (July — August 11,1985) Here, again, according to the government, Barrington attempted to bring in “the big load of cocaine.” This time, his plan was to take a commercial flight to Colombia, there obtain a Colombian aircraft, and fly it to Arauca, near Bogota, Colombia, where he would pick up the cocaine. He traveled to Colombia and then flew in a Colombian registered airplane with a Colombian pilot and co-pilot to Arau-ca. But he was arrested there, and the plane was seized on July 31 or August 1, 1985. Barrington had $13,800 in $100 bills with him at the time of the arrest. No drugs were found on the aircraft, nor did Colombian authorities charge Barrington with any narcotics offense. Count 27 charged Barrington, Goff, and Kuntze and others with conspiring to import more than one kilogram of cocaine from Colombia to the United States in or about July through August 11, 1985, in violation of 21 U.S.C. §§ 952, 960, and 963. B. Trial, verdicts and sentences At trial, numerous witnesses presented testimony as to the several episodes and a variety of extrinsic offenses. A number of issues arose in connection with procedures during the trial. Additional relevant facts will be set out below in connection with the issues raised on appeal. The jury returned verdicts on January 12,1987. With one exception, it found all appellants guilty on all counts. The court subsequently sentenced appellants to a combination of concurrent and consecutive sentences and fines totalling as enumerated: Barrington: 90 years and $1,000,000; Drewes: 35 years and $90,000; Goff: 50 years and $300,000; Kuntze: 35 years and $70,000; and Schoenhoff: 35 years and $260,000. II. ISSUES ON APPEAL Appellants filed timely appeals. Pursuant to Rule 28(i), Fed.R.App.P., appellants Drewes, Goff, and Kuntze adopted by reference all arguments, points and authorities pertaining to them that were presented by the other appellants. We turn first to contentions relating to all appellants and afterwards to those raised by appellants individually. A. Issues relating to all appellants Six issues potentially affect all appellants. Four of these can be treated briefly. Two others are more substantial. Five of these issues relate to procedural matters that occurred during the trial or sentencing. 1. Submission to the jury of an unedited copy of the indictment Appellant Schoenhoff contends that the original, unredacted, twenty-nine count indictment may have been given to the jury. In this event, he asserts that he and the other appellants would have suffered prejudice as a result of “extraneous” charges contained therein. He states that his trial counsel had advised him that evidence in the Barrington record “indicates a high probability” that the complete original indictment was given to the jury. Schoenhoff does not refer us to particular record pages. We find no indication in the Barrington volumes or elsewhere in the record that the jury saw the unredacted indictment. We do find that the trial judge told the jury that several counts had been omitted from the copy of the indictment he was giving them. We find this contention totally lacking in merit. 2. Invasion of jury privacy and ex parte communication Appellant Barrington asserts that jury deliberations were invaded when, on Friday, January 9, 1987, the trial judge received a partially completed verdict form from the presiding juror for “safekeeping” over the weekend. The court made a memorial as to this event in an order which sealed the form. Barrington first urges that appellants were prejudiced because “the jury must have considered themselves bound by the partial verdict — without any power to alter or change their tentative views.” He offers no evidence or cogent argument in support of this contention. Second, Bar-rington claims that the incident constituted proceedings outside the presence of defendants in contravention of Rule 43(a), Fed.R. Crim.P. Since safekeeping was the only purpose of the court’s action, this was not a court proceeding requiring the presence of the accused. Third, he complains that the requirement of Rule 31(a) that jury verdicts be returned to the judge in open court was violated, and cites various cases holding that a judge’s questioning a jury during the course of its deliberations regarding its numerical division is reversible error. Appellant, however, offers no evidence that any portion of a jury verdict was “returned” to the judge or that the court engaged in such questioning. The form was simply a jury worksheet at that time. We find no error. 3. Arbitrary or politically-motivated sentencing Appellant Barrington contends that the court’s remarks at the time of sentencing indicated improper political motivation. The court’s statement was as follows: Let me make this general comment that will apply to this case today and I won’t repeat it with each. Congress has recognized a significant problem caused by drugs in this country. Just last fall it enacted the Antidrug Abuse Act of 1986 which involves very, very stiff penalties, much stiffer than those that apply in this case. What I am saying is that the people of this country through their elected representatives have made it very plain how they feel about drugs and the drug problem. ... They end up in the hands of children as well as adults. Now, I have before me a man who has been found guilty by a jury beyond a reasonable doubt on several repeated instances of trying to bring drugs into this country. In my opinion, based on the evidence, he has shown call[o]us disregard for the laws of this country. I don’t believe leniency is appropriate in this case at all. I don’t think I need to say anything else. The sentence will reflect my feelings on it. Clearly the first two paragraphs quoted were meant to apply to all appellants, not only to Barrington. Barrington asserts that the judge was “acting more as a legislator than a jurist,” by imposing a sentence “far exceeding the range of propriety,” and that the sentence was therefore cruel and unusual in violation of the Eighth Amendment. The court might more aptly have referred to public policy considerations rather than to its own “feelings,” but it clearly did not abuse discretion by referring to societal concerns. Courts have “very wide discretion” in determining an appropriate sentence. Wasman v. United States, 468 U.S. 559, 563, 104 S.Ct. 3217, 3220, 82 L.Ed.2d 424 (1984). It is not improper for a court to consider the adverse effects of drugs on communities, a convicted offender’s persistent disrespect for the law, or his leadership role in drug trafficking activities. United States v. White, 748 F.2d 257, 261 (5th Cir.1984); United States v. Hawkins, 658 F.2d 279, 289-90 (5th Cir.1981); United States v. Jackson, 649 F.2d 967, 983 (3d Cir.), cert. denied, 454 U.S. 1034, 102 S.Ct. 574, 70 L.Ed.2d 479 (1981). The sentences were related to acceptable goals of punishment, and are not grossly disproportionate to the severity of the offenses for which appellants were convicted. They were not, therefore, cruel and unusual. Coker v. Georgia, 433 U.S. 584, 593, 97 S.Ct. 2861, 2866 (1977). We conclude that the court’s sentencing violated no constitutionally protected rights. 4. Admission of testimony by paid informer Tom Spratlen Appellants Drewes, Goff, Kuntze, and Schoenhoff argue that the district court committed reversible error by denying their motions with respect to testimony by the government’s paid informer and principal witness, Tom Spratlen. They contend that the court erred by admitting Sprat-len’s testimony, by denying their motion to strike that testimony in its entirety, by failing to give the jury special cautionary instructions regarding it, and finally, by denying their motion for mistrial because of it. Record evidence indicates that Spratlen had “heard” that the government had targeted Barrington and would pay as much as $250,000 for evidence against him. Spratlen then approached the government and became a government informer in September, 1984. By the time of trial, he had already received over $62,000 in expenses and “reward” payments. The evidence further shows that a DEA agent present throughout Spratlen’s testimony planned to recommend at some time “in the future” that he be paid an additional amount between $100,000 and $200,000. Further, it was shown that in return for giving his testimony, Spratlen expected to receive a percentage of the money and other property seized from appellants. Finally, Sprat-len indicated that he believed the total amount he was to receive, possibly as much as $250,000, would depend upon the success of the prosecution. Under our en banc decision in United States v. Cervantes-Pacheco, 826 F.2d 310 (5th Cir.1987), cert. denied, sub nom. Nelson v. United States, — U.S. —, 108 S.Ct. 749, 98 L.Ed.2d 762 (1988), the credibility of a compensated witness, like that of a witness promised a reduced sentence in exchange for testifying, is for the jury to determine. The government may not, of course, deliberately use or encourage the use of perjured testimony. It must make complete and timely disclosure to the accused concerning any fee arrangement with the informant, and the accused must have adequate opportunity to cross-examine the informant and government agents about any agreement to compensate. Further, the trial court must give the jury careful instructions pointing out the suspect credibility of a fact witness who has been or expects to be compensated for his testimony. Id. at 315-16. Appellants had full opportunity to cross-examine Spratlen and government agents as to compensation arrangements, and they did so extensively in the course of trial. The court properly instructed the jury. Appellants do not claim that the government deliberately put on perjured testimony or failed to make complete and timely disclosure as to its fee arrangement with Sprat-len. We find that the court did not err by denying appellants’ motions regarding Spratlen’s testimony. 5. Prosecutorial misconduct All appellants present a series of claims concerning alleged prosecutorial misconduct during trial and in closing argument. We immediately dispose of their contention that during trial the prosecutor improperly stated that some of the defense attorneys and their clients spoke Spanish. The jury was instructed to disregard the remark, and no prejudice was shown. More serious objections are made to the prosecutor’s closing argument. It is urged that he improperly attempted to bolster the credibility of government witness Spratlen’s testimony. Further he is charged with improperly attacking the integrity of defense counsel. Finally the claim is made that he improperly undertook to bolster the government’s case by emphasizing the official nature of his office as government prosecutor, by implying that he had personal knowledge as to appellants’ guilt based on out-of-court information, by asserting his own personal opinion as to their guilt, and by stating that their guilt was known to other branches of government. Appellants contend that the prosecutor’s conduct abridged their Fifth Amendment due process rights and their Sixth Amendment right to assistance of counsel. (a) Bolstering credibility of witness Spratlen’s testimony Appellant Goff complains that the government prosecutor improperly bolstered Spratlen’s credibility by offering his personal opinion as to the latter’s veracity. In closing argument, the prosecutor stated: First of all, they have got to convince you that Tom Spratlen was lying because Tom Spratlen was right in the middle of all this that was going on. He was there in person and he’s telling the truth and he makes each of them guilty of everything they are charged with in the indictment. They have got to convince you he’s lying. Counsel for appellant Drewes objected that the quoted argument misstated the court’s charge as to the burden of proof. None of the appellants, however, objected at trial to the prosecutor’s bolstering the credibility of Spratlen’s testimony. Consequently, this Court must apply plain error analysis to determine whether the prosecutor’s argument seriously affected the fairness, integrity, or public reputation of judicial proceeding and resulted in a miscarriage of justice. United States v. Livingston, 816 F.2d 184, 195 (5th Cir.1987). The government contends that the prosecutor’s comments “were largely responsive to the attacks by defense counsel upon the credibility of government witnesses.” We conclude that this instance of bolstering, standing alone, does not constitute plain error. We shall consider it further, however, in connection with other instances of alleged prosecutorial misconduct. (b) Attacks by prosecutor on integrity of defense counsel Appellants Barrington, Drewes, and Goff contend that in closing argument, the prosecutor improperly engaged in personal attacks on their attorneys. They urge that these attacks went beyond merely rehabilitating government witnesses against challenges by defense counsel. They complain that by inviting the jury to disbelieve and distrust everything defense counsel told them the government seriously hampered their ability to provide a defense and exercise their right to counsel under the Fifth and Sixth Amendments. Appellants cite the following statements by the prosecutor, among others, as examples of this kind of misconduct: Every lawyer that has spoken to you from the defense side has taken things out of context. They have ... cut off what they wantfed] to cut off and told you what they wanted [you] to hear and in some cases flat out misstated what the evidence was. I thought most of the questions [counsel for Goff] asked in some way were a trick question ... I will suggest to you the — their job is to represent their clients. My job is to represent the United States. I’m not going to tell you what oaths I take and what obligations I have ... Appellants timely objected to the prosecutor’s personal attacks on counsel and moved for mistrial. The court overruled the objection and denied the motion for mistrial. These attacks on defense counsel fall well short of those that required reversal in United States v. McDonald, 620 F.2d 559 (5th Cir.1980) (prosecutor implied that defendant’s lawyer helped destroy evidence) or Bruno v. Rushen, 721 F.2d 1193 (9th Cir.1983), cert. denied sub nom. McCarthy v. Bruno, 469 U.S. 920, 105 S.Ct. 302, 83 L.Ed.2d 236 (1984) (prosecutor suggested that defendant’s hiring counsel proved his guilt and that all criminal defense counsel lie and distort facts). They are roughly comparable to statements by the prosecutor in Livingston, 816 F.2d 184, to the effect that defendants’ counsel “had tried to ‘disguise’ the truth and create doubt where none existed.” Id. at 195. Defense counsel in Livingston failed to object, and we declined to find plain error. Here, counsel did object, and the court overruled the objection. We defer considering whether these attacks on counsel were harmless until we have considered appellants’ remaining points of error regarding possible prosecutorial misconduct. (c) Prosecutor’s bolstering case by emphasizing his official position and the asserted views of other branches of government involved Appellants Barrington, Drewes, and Goff make three closely related claims with respect to another statement by the prosecutor in closing argument. He improperly invoked his official status as government prosecutor to bolster the government’s case. He strongly implied that he knew that appellants’ guilt was known to other branches of government outside the judicial process. And he invoked the authority of other branches of government as a basis for convicting appellants. The statement is as follows: I will suggest to your the — their job is to represent their clients. My job is to represent the United States. I’m not going to tell you what oaths I take and what obligations I have; but I’ll tell you one thing, if you believe what these lawyers have suggested to you and some of them have out and out said then you’ve got to believe that there is a conspiracy but the conspiracy started apparently in Las Vegas and involves the Internal Revenue Service, the Drug Enforcement Administration, the F.B.I., the Texas Department of Public Safety, the United States Attorneys Office, at least in this district and maybe even a judge or two and has [sic ] just not the case and they know it. Appellants did not object to this statement at trial. We have previously held that it is particularly improper, indeed, pernicious, for a prosecutor to seek to invoke his personal status as the government’s attorney or the sanction of the government itself as a basis for convicting a criminal defendant. United States v. Garza, 608 F.2d 659, 663 (5th Cir.1979). We have also held that the prosecutor may not suggest that evidence which was not presented at trial provides additional grounds for finding a defendant guilty. Id. In Garza we found plain error and reversed. Here the prosecutor’s recitation of government agencies and entities which, he clearly implies, knew appellants to be guilty is improper in the light of what we said in Hall v. United States, 419 F.2d 582 (5th Cir.1969). In considering the impact of what is said the court also must be concerned with the great potential for jury persuasion which arises because the prosecutor’s personal status and his role as a spokesman for the government tend to give what he says the ring of authenticity. The power and force of the government tend to impart an implicit stamp of believability to what the prosecutor says. That same power and force allow him, with a minimum of words, to impress on the jury that the government’s vast investigatory network, apart from the orderly machinery of the trial, knows that the accused is guilty or has non-judicially reached conclusions on relevant facts which tend to show he is guilty. Id. at 583-84. If such guidance were not enough, prosecutors should be fully in compliance with the often-repeated, staunch words of Mr. Justice Sutherland in Berger v. United States, 29 U.S. 78, 88, 55 S.Ct. 629, 633, 79 L.Ed. 1314 (1935): The United States Attorney is the representative not of an ordinary party to a controversy, but of a sovereignty whose obligation to govern impartially is as compelling as its obligation to govern at all; and whose interest, therefore, in a criminal prosecution is not that it shall win a case, but that justice shall be done.... It is fair to say that the average jury ... has confidence that these obligations, which so plainly rest upon the prosecuting attorney, will be faithfully observed. Consequently, improper suggestions, insinuations, and, especially, assertions of personal knowledge are apt to carry much weight against the accused when they should properly carry none. Id. See also United States v. Young, 470 U.S. 1, 105 S.Ct. 1038, 1048, 84 L.Ed.2d 1 (1985). The prosecutor further suggested that in order to find appellants not guilty, the jury would have to believe that several governmental agencies and even perhaps federal judges had engaged in a malevolent and illegal conspiracy to convict them. This also was improper argument. See United States v. Dorr, 636 F.2d 117, 119-21 (5th Cir.1981); United States v. Herrera, 531 F.2d 788, 790 (5th Cir.1976). Confronted with such argument, jurors could be expected to feel that in order to find appellants innocent they would have to abandon confidence in the integrity of government. “The role of the prosecutor in closing argument is to assist the jury in analyzing, evaluating, and applying the evidence.” Garza, 608 F.2d at 662. It is not to invoke jurors' loyalty to their country or its government as a reason for convicting the accused. Herrera, 531 F.2d at 789-90. (d) Expressions of opinion as to appellants’ guilt Finally, appellants contend that the district court erred by overruling their objection and denying their motion for mistrial based on the prosecutor’s repeated impermissible comments on their guilt during closing argument. These comments included the following: [Government agents] were able to make those two seizures of marijuana without the crooks figuring out how that happened. [I]f you believe the kind of things that these lawyers have suggested that you should believe so that their guilty clients in the face of tremendous evidence can go free then the first thing you ought to do is to find them not guilty and the second thing you ought to do is go up and talk to the United States Attorney and maybe even go higher than that, [to the] head of [the] Drug Enforcement Administration, [and the] head of the Internal Revenue Service. We have held that characterizing a defendant as a “hoodlum” was prejudicial error that the trial court on its own motion should have instructed the jury to disregard. Hall, 419 F.2d at 587. The prosecutor’s characterization of appellants here as “crooks” is not distinguishably less prejudicial or improper. Further, the prosecutor should not have characterized appellants as their attorneys’ “guilty clients.” This statement poses appellants’ guilt as a pre-determined fact. The remark was, moreover, another effort to lead jury members to believe that the whole governmental establishment had already determined appellants to be guilty on evidence not before them. Garza, 608 F.2d at 665; Hall, 419 F.2d at 587. These remarks are the sort of “foul blows” that the Supreme Court and this Court have long held improper. Berger, 55 S.Ct. at 633; Hall, 419 F.2d at 588. By themselves, the prosecutor’s comments implying his personal belief in appellants’ guilt constitute prejudicial error. In addition, on separate occasions the prosecutor attempted to bolster the credibility of a key government witness by assuring the jury that the witness was telling the truth. His insinuation that appellants should be found guilty because their attorneys were trying to deceive the jury was clearly an improper tactic. The prosecutor implied that extra-judicial governmental agencies and personnel had knowledge of appellants’ guilt, and he invoked the dignity of his oaths and office as well as the sanctity of state and federal governmental agencies in order to persuade the jury that they should find appellants guilty. These statements were impermissible. We do not reach the question whether these other instances of misconduct, taken separately or in the aggregate, also rise to the level of error. Their cumulative effect only adds to the prosecutor’s misconduct. Garza, 608 F.2d at 665-66; Herrera, 531 F.2d at 790. We do summarize, however, by stating that the record reveals overzealous and flamboyant argument by the prosecutor which clearly went beyond the pros-ecutorial propriety defined by the Supreme Court in Berger and by this Court in Hall, supra. Reversal and remand for a new trial is the traditional remedy for prosecutorial conduct. It is not, however, automatic. The weight of the evidence in the particular case is also to be considered. United States v. Jones, 839 F.2d 1041, 1049 (5th Cir.1988); United States v. Weddell, 800 F.2d 1404, 1410-11 (5th Cir.1986). The crucial question on review is whether the prosecutor’s remarks cast serious doubt upon the correctness of the jury’s verdict. “Where a reviewing court can find that the record developed at trial establishes guilt beyond a reasonable doubt, the interest in fairness has been satisfied and the judgment should be affirmed.” Jones, at 1049. The basic question, then, is whether the jury would have found appellants guilty had it not been for the prosecutor’s improper argument. We consider the following factors in carrying out such a review: (1) the magnitude of the prejudicial effect of the statements, (2) the efficacy of any cautionary instructions, and (3) the strength of the evidence of appellants’ guilt. Jones, at 1050; United States v. Cardenas, 778 F.2d 1127, 1131 (5th Cir.1985); United States v. McPhee, 731 F.2d 1150, 1152 (5th Cir.1984). We have already concluded that the prosecutor’s statements were prejudicial. We note that the court did not issue any special cautionary or curative instructions. It is doubtful that its general instructions were sufficient to counter the effect of at least some of the prejudicial statements. We must therefore consider the strength of the evidence as to appellants’ guilt. A conviction should not be set aside if the prosecutor’s conduct did not in fact contribute to the guilty verdict and was, therefore, legally harmless. Cardenas, 778 F.2d at 1130; United States v. Beckett, 706 F.2d 519, 520 (5th Cir.1983). Here, there are five appellants charged on multiple counts, so we confront, in effect, forty different verdicts with the role of prosecutorial misconduct in mind. Before turning to the points of error, including the sufficiency of the evidence, raised by individual appellants, we consider one final set of contentions affecting them all. 6. Existence and Number of Conspiracies Four appellants urge that the evidence showed that they were guilty, at most, of participation in a single conspiracy which the government arbitrarily divided into multiple conspiracy counts, and that their convictions on these counts contravene the Double Jeopardy Clause. The other appellant, Schoenhoff, argues similarly with respect to his convictions on conspiracy counts 9, 14 and 20. All five appellants were charged in two of the conspiracy counts (14 and 20), and each is charged in at least one of the others (counts 6, 9, 11, 25 and 27). We consider whether the government met its burden in proving the existence of the separate conspiracies charged. We reserve for later consideration the sufficiency of the evidence as to each appellant’s participation in particular conspiracies. In a drug conspiracy case, the government must prove beyond a reasonable doubt that the charged conspiracies existed. United States v. Morgan, 835 F.2d 79, 82 (5th Cir.1987). Under 21 U.S.C. §§ 846 and 963, the crucial element of a conspiracy is an agreement between two or more persons to commit the offense. Id.; United States v. Gardea Carrasco, 830 F.2d 41, 44 (5th Cir.1987). If there is a single agreement that has as its objective the commission of crimes on different occasions, there is still but one conspiracy. United States v. Kalish, 690 F.2d 1144, 1151 (5th Cir.1982), cert. denied, 459 U.S. 1108, 103 S.Ct. 735, 74 L.Ed.2d 958 (1983); United States v. Marable, 578 F.2d 151, 153-54 (5th Cir.1978). For each conspiracy conviction it seeks, the government must prove a corresponding separate agreement. United States v. Olivares, 786 F.2d 659, 664 (5th Cir.1986); United States v. Winship, 724 F.2d 1116, 1126 (5th Cir.1984). Because it is usually difficult to identify the objectives of and the parties to an unlawful agreement, the courts must look to circumstantial evidence in order to determine the conspiracy’s scope. Kalish, 690 F.2d at 1151. Such evidence may include the conduct of the alleged participants or evidence of a plan or scheme. Morgan, 835 F.2d at 82; United States v. Ayala, 643 F.2d 244, 248 (5th Cir.1981). The evidence, however, must show beyond a reasonable doubt that two or more persons came to a mutual understanding to undertake to violate the particular laws in question. Morgan, 835 F.2d at 82. This Court has established a five-step analysis in order to determine whether the record demonstrates that a given criminal venture constitutes one or more conspiracies. Our approach derives from recognition that the essence of a conspiracy offense lies in the agreement to violate the law. Winship, 724 F.2d at 1126. The five inquiries are commonly referred to as the Marable factors. United States v. Marable, 578 F.2d 151, 154 (5th Cir.1978). They are: (1) the time frames during which the alleged conspiracies occurred; (2) the extent to which the same persons were involved and the nature of their involvements; (3) whether the statutory offenses charged in the indictments were the same; (4) whether the nature and scope of the defendants’ activities charged in connection with each alleged conspiracy were repetitive and continuous; and (5) whether the locations where the events alleged as part of each conspiracy took place were the same. United States v. Atkins, 834 F.2d 426, 432-33 (1987); United States v. Nichols, 741 F.2d 767, 771 (1984), cert. denied, 469 U.S. 1214, 105 S.Ct. 1186-87, 84 L.Ed.2d 333 (1985); Winship, 724 F.2d at 1126; Kalish, 690 F.2d at 1151-52; Marable, 578 F.2d at 154. Both in opening and closing argument, the government itself repeatedly argued that all of the charged activities, including those involving marihuana, were part of a single, on-going plan to bring in one big load of cocaine. Yet the government did not charge appellants with taking part in a single, on-going conspiracy. Instead, it charged appellants under seven different conspiracy counts, and the jury was instructed accordingly. What the government intended by continuing to argue that appellants’ activities all related to an on-going plan to bring in “the big load of cocaine” is unclear. Perhaps it meant for the jury to assume that appellants’ putative agreement to do so would carry over to show that they had also agreed to commit the seven separate conspiracies within the year and a half time frame. If so, such argument was misleading. For each conspiracy conviction the government seeks, it must prove a corresponding, separate agreement. Winship, 724 F.2d at 1126. Throughout trial, the government gave curiously scant attention to its burden of proving that two or more persons had agreed to commit the offenses charged in each of the seven conspiracy counts. Much of the evidence presented was circumstantial, and was generally offered without reference to particular days, months, or even years. The government rarely focused either testimony or argument on any of the specific counts charged. The same names and locations figured in several different charged conspiracies, and it often is difficult or impossible to tell which count is being addressed. Confusion is compounded by the fact that a substantial portion of the testimony had to do with extrinsic offenses, some of which were described in great detail, although typically without reference to dates, involving many of the same persons and locations featured in the charged offenses. As set out below, applying the five Mar-able factors, we find ample record evidence from which to conclude that the government demonstrated the existence of three conspiracies: those two charged in counts 9 and 11 or 14 and 20, and the one in count 25. We do not find sufficient evidence to establish the existence of the conspiracies charged in counts 6 and 27. Count 6: The “Fort Stockton” cocaine conspiracy, June-October 1984 Because this is chronologically the first charged conspiracy we need not apply Marable analysis. The question here is whether the record reveals that the government presented strong evidence that two or more persons agreed to commit the charged offense. We find that it does not. Government witness Spratlen testified as to certain conversations regarding cocaine smuggling and his understanding of what the “plan” would be. He testified that Goff had flown about the Fort Stockton, Texas, vicinity to show him where the load might be dropped. Another alleged conspirator testified that Goff had told him he could make $5,000 by watching a gate on the road to the site where a load of drugs from Colombia would be dropped, and that he (Goff) and Barrington would be on the plane. There is also testimony that Goff had flown over a pipeline road near Fort Stockton where “a load of drugs” would be dropped. Spratlen did not state he had been present when any agreement to import cocaine was reached. Goffs participation in discussing possible arrangements for smuggling cocaine could indicate the existence of an agreement, and thus a conspiracy, to import cocaine and his participation in it. However, by the time Goff and Spratlen flew around Fort Stockton, the latter evidently had become a government informer. Neither Goff nor anyone else would have been able to conspire with Spratlen. It is unclear from other testimony whether the drug drop he discussed with Goff was the one charged in count 6. Goff “did not say when” the contemplated drop would take place. Goff’s reconnoitering flight near Fort Stockton may just as well have been preparatory to the Tye marihuana drop, which was to be along a pipeline road near Fort Stockton. Substantial evidence at trial indicated that all discussions during the period of the alleged conspiracy were only preliminary, and that no agreement to import cocaine was reached until after the time frame of the alleged conspiracy. Such testimony came directly from government witnesses who were present at these discussions. Moreover, there was testimony by a government witness that only Barrington was engaged in planning the charged importation. Though circumstantial evidence could indicate Goffs participation in the charged conspiracy, before that could be shown, it must first be proved beyond a reasonable doubt that the conspiracy existed, namely, that there was an agreement to commit the unlawful act or acts charged. Morgan, 835 F.2d at 82. The existence of such an agreement may, of course, be proven by circumstantial evidence. Here, however, the circumstantial evidence was vague, undated and speculative. In contrast, there was explicit, consistent testimony from several sources including government witnesses that agreement had not been reached. We conclude that the evidence as to the existence of the conspiracy charged in count 6 is not enough, and that appellants’ convictions under this count must be reversed. Counts 9 and 11: The “Tye” marihuana conspiracy More than ample evidence supports the jury’s finding that a conspiracy existed in connection with the “Tye load” or episode. Several witnesses testified as to participation by Goff, Drewes, and others in preparation for and execution of the plan. Goff was said to be in charge of the operation. Two defendants rigged an auxiliary gasoline tank to provide the aircraft enough fuel for the trip to Belize. Bar-rington loaned his Loran instrument to the pilots. Goff and Drewes told Gantt they had the load of marihuana in his hangar. Two other defendants then transferred the marihuana to a truck, which contained over 900 pounds of marihuana when it was seized. Appellants argue that separate convictions under counts 9 and 11 are multiplicious and violate the Double Jeopardy Clause. It is well settled, however, that the government can impose a separate punishment for each statute a conspirator has agreed to violate, even if there is only one agreement, provided that Congress has authorized such punishment. Sections 846 and 963 are such statutes. Albernaz v. United States, 450 U.S. 333, 101 S.Ct. 1137, 1140-41, 1145 n. 3, 67 L.Ed.2d 275 (1981); Kalish, 690 F.2d at 1151 n. 6. Since the Tye conspiracy violated both conspiracy sections, appellants may be convicted and sentenced under both counts 9 and 11. Counts 14 and 20: The “Granbury” Marihuana Conspiracy Here again, more than ample testimony supports the jury’s finding of a conspiracy to commit the activities charged. Though most of the testimony came from Spratlen, it was generally corroborated by other witnesses. There was testimony that a number of bags of marihuana had been picked up at the drop site. There was testimony that Barrington, Drewes, and Goff had said that they could not find seven missing bags of marihuana. Officer Lee testified that he and other government agents seized some 900 pounds of marihuana at Granbury and arrested three defendants there. Again, under Albernaz, supra, appellants were subject to conviction and sentencing under both counts 14 and 20. Appellants vigorously contend that the Tye and Granbury episodes were parts of a single continuing conspiracy, and that counts 14 and 20 are multiplicious with respect to counts 9 and 11. They urge that their convictions under both sets of counts therefore violate the Double Jeopardy Clause. To determine whether the evidence describes a single conspiracy or two separate ones, we apply the Marable factors, keeping in view the central question: whether the government has proven a separate, corresponding agreement for each conspiracy conviction it seeks. United States v. Levy, 803 F.2d 1390, 1394 (5th Cir.1986); Winship, 724 F.2d at 1126. Where appellants come forward with a non-frivolous double jeopardy claim, the burden is placed upon the government to prove separate conspiracies by a preponderance of the evidence. Nichols, 741 F.2d at 771; United States v. Stricklin, 591 F.2d 1112, 1118-19 (5th Cir.1979). Appellants present such a claim here. (1) Time. The Tye conspiracy allegedly occurred between November and December 3, 1984. The Granbury conspiracy allegedly took place between November 28,1984 and January 17, 1985. Thus the Tye conspiracy overlapped the Granbury conspiracy by six days. The government claims that the time overlap here is minimal. This consideration would not be dispositive, even if there were some time gap between the charged incidents, for the prosecution is not free to separate a single, on-going conspiracy into discrete conspiracies simply by dividing the time frames. United States v. Manotas-Mejia, 824 F.2d 360, 366 (5th Cir.1987), cert. denied sub nom. Ramirez-Rios v. United States, — U.S. —, 108 S.Ct. 354, 98 L.Ed.2d 379 (1987); United States v. Dunn, 775 F.2d 604, 607 (5th Cir.1985). See also Kalish, 690 F.2d at 1151. The government’s main argument for finding that the Tye and Gran-bury conspiracies were separate is that “arrests have been held to constitute a terminal point for a conspiracy,” citing Dunn, 775 F.2d at 607. This is not correct. Dunn states, in relevant part, “It is well settled that a person’s participation in a conspiracy ends when the person is arrested for his role in the conspiracy.” Id. (Emphasis added.) See also United States v. Postal, 589 F.2d 862, 888 (5th Cir.), cert. denied, 444 U.S. 832, 100 S.Ct. 61, 62 L.Ed.2d 40 (1979). The two persons arrested on December 2 and 3, 1984, played only minor roles and their arrests are totally irrelevant as to the duration of the Tye conspiracy. Even when several members of a conspiracy are arrested, the conspiracy itself is not thereby necessarily terminated. Kalish, 690 F.2d at 1151; United States v. Michel, 588 F.2d 986, 993-94 (5th Cir.), cert. denied, 444 U.S. 825, 100 S.Ct. 47, 62 L.Ed.2d 32 (1979). Drug conspiracies involving multiple importation episodes may continue for many months. Nichols, 741 F.2d at 771 (6 months); Michel, 588 F.2d at 990 (2 years); United States v. Ruigomez, 576 F.2d 1149, 1150-51 (5th Cir.1978) (8 months); see also Atkins, 834 F.2d at 432; United States v. Stricklin, 591 F.2d 1112 (5th Cir.1979). The fact that the Tye and Granbury importations took place within a six-week time frame is exceedingly weak evidence to show that these episodes constituted separate conspiracies. (2) Alleged co-conspirators. The same four principals were involved in both episodes: Barrington, Drewes, Goff, and Sehoenhoff. There was some turnover in other personnel. But even considerable difference or turnover in personnel between or among ventures does not prove separate conspiracies. In Kalish, all four crew members on board a shrimp boat used for the first importation were arrested when the load was seized, while two dozen or more new co-conspirators took part in the second importation. Only four persons were involved in both episodes. Kalish, 690 F.2d at 1151. Yet we held the fact “[t]hat the conspiracy must take on additional members to accomplish one of its objects does not in itself establish a different conspiracy.” Id. In the course of a single conspiracy various “players” such as off-loaders, pilots, and financiers, may move “onstage and off.” Nichols, 741 F.2d at 771. “A mere shuffling of personnel in an otherwise on-going operation with an apparent continuity will not, alone, suffice to create multiple conspiracies.” Id. at 772. Three of the four principals had exactly the same roles in both the Tye and the Granbury episodes. Sehoenhoff was the supplier in Belize for both shipments, and he also traveled to Texas after each shipment to monitor its distribution. Goff and Drewes piloted the airplanes used for both flights. Two of the ground crew were the same both times. The only notable difference between the two episodes is some testimony indicating that Goff was in charge of planning the Tye load, while Barrington directed the Granbury operation. This difference, however, appears at most to be a matter of degree. Barrington was substantially involved in the Tye affair. Without going into the evidence in further detail, we stress that our cases do not require that a single conspiracy must have the same person or persons direct each operation within it. In Michel, for example, the active leader of the first series of marihuana importations then receded into the background, though retaining his financial interest, while others organized subsequent ventures. Michel, 588 F.2d at 991-94. A single plan does not turn into several plans simply because some members of the conspiracy are cast in more vital roles than others, or because of internal personnel changes. Id. at 995. We conclude that possible variation in the extent to which Barrington was in charge does not constitute a difference sufficient to show that the two episodes arose in the context of separate conspiracies. (3) Statutory offenses charged. The Tye conspiracy counts, 9 and 11, respectively, charged that appellants violated 21 U.S.C. § 963, which prohibits conspiracies to import, and 21 U.S.C. § 846, which prohibits conspiracies to possess with intent to distribute. The Granbury conspiracy counts, 14 and 20, respectively, charged violations of the same two sections. This circumstance has virtually no significance one way or the other in this case. (4) Nature and scope of the activities. The government concedes that a meeting attended by Barrington, Drewes, Goff and others on November 28,1984 at the Sunday House in Fort Worth, Texas, pertained to both the Tye and the Granbury alleged conspiracies. The Tye and Granbury episodes both followed a similar pattern. A load of marihuana, in each case weighing approximately a thousand pounds, was supplied in Belize by Schoenhoff. Both loads were transported via aircraft with the same pilots flying round-trip from Texas to Belize and back. Both loads were to be “kicked” or dropped off in secluded locations along an oil pipeline. Two members of the “ground crew” were the same both times. After each delivery, the marihuana was transferred to a truck, which was parked at an intermediate location for some interval and then driven by others for further transfer or distribution. In both cases Schoenhoff evidently traveled from Belize to supervise the distribution process. In both cases, Barrington aided in the ventures, and may have directed them. In United States v. Henry, 661 F.2d 894 (5th Cir.1981), cert. denied, 455 U.S. 992, 102 S.Ct. 1619, 71 L.Ed.2d 853 (1982), where we found two separate conspiracies, the locus of one was Detroit, while the other centered in Dallas and Atlanta. Only one person was common to both conspiracies, and there was no evidence suggesting cooperation between the two groups. Id. at 897. Here the pattern of operations is much closer to the facts in Nichols and Michel, which led us, in each case, to conclude that there was but a single underlying conspiracy. In Nichols, the accused carried out three of four planned cocaine smuggling importations from Colombia to the United States during a six month period. The importation episodes had common planners. But the cocaine suppliers in Colombia were different, one of the pilots was different, different aircraft were used, and the intermediaries dropped out after the first two trips. The Michel conspiracy was more loosely organized. There were over a dozen separate episodes in which marihuana was flown from at least two different locations in Mexico to more than six different sites in Texas. At least three separate aircraft were flown by five different pilots. Nevertheless, we concluded: That each flight was a random, separate venture discrete from the others defies belief. The group’s efforts to maintain protected landing sites and the continuous planning and cooperation between the persons involved convince us that this was one scheme to import marihuana which envisioned as many flights as could safely be made. Michel, 588 F.2d 986, 995. A similar comment could be made about the two marihuana ventures in the present case. (5) Locations. In both cases, appellants’ and other defendants’ activities were alleged to have taken place “in the Dallas [or Fort Worth] Division of the Northern District of Texas, and elsewhere.” Belize was the source of the marihuana in both cases, and the intended drop sites, Fort Stockton and Pecos, were in the same vicinity in west Texas. We conclude from our review of the record that, in the light of the Marable factors, the Tye and Granbury episodes constituted a single, on-going conspiracy. The Double Jeopardy Clause therefore prohibits appellants’ convictions on more than one set of counts. The appropriate remedy for violation of the Double Jeopardy Clause is to vacate the sentences in question and remand with instructions to reverse and dismiss all but one set of the redundant convictions. Olivares, 786 F.2d at 664. The government may elect which set of counts is to be dismissed: either counts 9 and 11, or counts 14 and 20. Count 25: The “Maraquita” cocaine conspiracy The existence of the charged Maraquita conspiracy is established well beyond any reasonable doubt. Spratlen and four others involved testified concerning specific agreements, meetings and activities. This testimony constitutes strong evidence that Barrington and several others had agreed to import cocaine from Colombia during the period January to July, 1985. Appellants contend that, as the government urged in opening and closing argument, there was only one conspiracy, namely to bring in “the big load of cocaine” and that the marihuana ventures were incidental to but part of that inclusive and continuing conspiracy. They urge that the offense charged in count 25 was part of this single conspiracy. Since we found the evidence too weak to establish the existence of the cocaine conspiracy charged in count 6, we do not consider the relation between the conspiracies charged in counts 6 and 25. But we must evaluate the relationship between the cocaine conspiracy charged in count 25 and the Tye-Granbury conspiracy, applying the Marable factors. (1)Time. There is an overlap of seventeen days in January 1985, between the Granbury time frame and that of the count 25 conspiracy. None of the activities charged in connection with Granbury, however, related to preparation for the Mara-quita episode. The only January, 1985, act charged in count 25 concerned Barrington’s arranging for Gantt to sell his Titan aircraft, allegedly in order to raise money to finance the anticipated cocaine deal. (2) Alleged co-conspirators. All appellants except Kuntze were charged in connection with the Tye episode and all five were charged under the Granbury conspiracy counts. Only Barrington and Kuntze were charged in count 25. One other person was charged under all Tye and Gran-bury counts, and also under count 25; two others were charged in connection with both Granbury and count 25. That is the extent of the overlap. Twelve persons including appellants Drewes, Goff, and Scho-enhoff who were charged in connection with the marihuana episodes do not appear under count 25. Moreover, eight defendants named in count 25 were not charged under the Tye or Granbury counts. Bar-rington was in charge of the Maraquita operation, as was clearly the case in the Granbury episode. Kuntze’s role, as at Granbury, was somewhat uncertain. There was a different “source” for the cocaine in Colombia in the place of Schoen-hoff, the marihuana supplier in Belize for the Tye-Granbury loads. Three new persons appeared in the role of intermediates or brokers for the count 25 cocaine. Contrary to his pattern in the marihuana flights, Barrington, himself, went along this time. No evidence at all connects the former Tye-Granbury pilots, Drewes and Goff, with the Maraquita trip. Two new ground crew members appeared for the first time. The cast of characters in the Maraquita conspiracy was significantly different than in Tye-Granbury. (3) Statutory offenses charged. Count 25 charged that appellants Barrington and Kuntze conspired to import cocaine in violation of 21 U.S.C. §§ 952, 960 and 963. Counts 9 and 14 charged violation of these same statutes by the importation of marihuana. In addition, counts 11 and 20 charged appellants with conspiracy to possess marihuana with intent to distribute in violation of 21 U.S.C. §§ 841(a)(1) and 846. The fact that different controlled substances were involved is not dispositive as to whether there were separate conspiracies. Winship, 724 F.2d at 1127; Marable, 578 F.2d at 154-56. It may suggest, however, that the nature of the activities was different. (4) Nature and scope of the activities. The overt acts charged in connection with the Tye-Granbury conspiracy were all different from those charged under count 25. There was uncontroverted testimony by a newly named conspirator that the witness had conspired with Barrington, Kuntze, and others to commit the offense charged in count 25. There was no evidence that proceeds of the prior marihuana ventures were to be used, or were in fact used, to finance the Maraquita transaction. The only similarity between the Tye-Granbury marihuana conspiracy and the Maraquita plan is that each involved round-trip flights from the United States to points South to pick up contraband which then would be dropped in a secluded area