Full opinion text
RIPPLE, Circuit Judge. In April 1987, a grand jury returned a two-count indictment against the five appellants in this case. The first count charged each of the five appellants with conspiring to travel in and use the facilities of interstate commerce to promote, carry on, and distribute the proceeds of unlawful activities involving prostitution. See 18 U.S.C. § 371; 18 U.S.C. § 1952(a)(1) & (3). The second count charged two of the appellants, John Paul Doerr and Josephine Christofalos, with conspiring to defraud the United States by obstructing the lawful functions of the Internal Revenue Service (IRS). See 18 U.S.C. § 371. After a lengthy jury trial, each of the appellants was found guilty of the offense charged in Count One, and John Paul Doerr and Ms. Christofalos were found guilty of the offense alleged in Count Two. All five appellants now challenge their convictions. Their appeals raise a number of different issues for our consideration. We affirm the convictions of all the appellants. I. Facts The prostitution activities underlying the offense alleged in Count One of the indictment were concentrated in three businesses that were part of an entity known as Worldwide Enterprises, Incorporated: the WW I Club, located in Kenosha County, Wisconsin; the Relaxation Health Systems massage parlor located next to the WW I Club in Kenosha County; and the WW II Club, located in Lake County, Illinois. The clubs were nude dancing establishments that served no food or alcoholic beverages. The testimony at trial revealed that the prostitution activities at the clubs were conducted pursuant to the following general procedure. A customer entering the club would be required to pay a cover charge. He would then be directed to a table and joined by a “dancer.” After being seated, a waitress would approach the customer and ask him if he would like to purchase a drink (water or a soft drink) for himself and the dancer. Once the customer had purchased a drink, the waitress would return and ask the customer if he would like to go to a private area with the dancer. If the customer agreed and purchased a bottle of soda or water, at a cost of forty to fifty dollars, he would be taken to a "terrace,” consisting of a number of booths, in the rear of the club. The customer would then be asked to buy additional bottles, and, once sufficient bottles had been purchased, the dancer would engage in sexual acts with the customer. At the massage parlor, the customer would pay a flat fee for thirty minutes in a private room with a masseuse. The masseuse would then negotiate a “tip” with the customer. The amount of the tip would determine the degree of sexual contact that the masseuse had with the customer. At both the clubs and the massage parlor, customers could pay in cash or by credit card. Josephine Christofalos assumed control of these businesses when her husband, George Christofalos, died in March 1979. At that time, one of the nightclub waitresses described to Ms. Christofalos the prostitution activities taking place on the premises. During the summer of 1979, Ms. Chris-tofalos retained John Paul Doerr to assist her in managing the enterprise. He moved into a house next to the Kenosha club and massage parlor and maintained close contact with the operations (for example, an intercom system was installed between his house and the club and massage parlor). The other defendants each played lesser roles in the illegal enterprises. Archie Pix-ley participated in the management of the Kenosha club and massage parlor, and, when some of the massage parlor masseuses were arrested, Mr. Pixley posted their bail. Mr. Pixley’s wife, Christa, was a waitress at the Kenosha club. Dale Doerr participated in the management of the massage parlor. Dale lived in Kenosha with his father, John Paul Doerr, during two different periods: from September 1979 to September 1980 (his junior year in high school) and from September 1981 until May 11, 1982. During the spring of 1982, both Dale and his father left Kenosha and moved to California. While in Kenosha, Dale worked at the businesses managed by his father. He was identified at trial as the massage parlor’s assistant manager. In this capacity, he provided instructions on the treatment of customers, on proper work attire, and on scheduling. He also encouraged the massage parlor’s masseuses to earn greater revenues by increasing their sexual favors. He sometimes received the massage parlor’s receipts at the end of the evening, and, in January 1982, he became involved in the massage parlor’s bookkeeping activities. Dale also assisted his father in the operation of RH Credit Systems, a company that processed credit card transactions for the Kenosha club and massage parlor. Count Two of the indictment is based on a money-laundering scheme engineered by John Paul Doerr and Josephine Christofa-los. Much of the evidence of this scheme was discovered during an FBI undercover operation in which the FBI operated a credit card processing business known as the National Credit Service (NCS). Credit card receipts from the nightclubs and massage parlor were forwarded to NCS. NCS then provided payment for the receipts to Ms. Christofalos. At her direction, NCS left the payee line on many of these payment checks blank. Ms. Christofalos deposited most of these checks into various bank accounts, many of which had little connection with the clubs and massage parlor. In addition, eleven of these checks were provided to Mr. Doerr, who, as part of the money-laundering scheme, deposited them in the bank account of a church that he had formed, the Holy Temple of Christ the Redeemer and Early Day Saints Church. The checks were reported to the IRS on the church’s tax return as contributions that were exempt from taxation. The government contends that, in this way, Ms. Christofalos and Mr. Doerr avoided reporting significant portions of their businesses’ substantial revenues to the IRS and impeded the IRS from accurately computing their income. II. Analysis A number of issues are raised by all five appellants jointly, while the individual appellants each raise several other issues. We shall first address those issues raised jointly and then turn to the contentions of individual appellants. A. Issues Raised by All Appellants 1. Improper admission of coconspira-tors’ statements The coeonspirator exception to the hearsay rule, Fed.R.Evid. 801(d)(2)(E), provides that a statement is not hearsay if it is “offered against a party and is ... a statement by a coconspirator of a party [made] during the course and in furtherance of the conspiracy.” The appellants maintain that two out-of-court statements admitted at trial failed to satisfy the “in furtherance” requirement of the coconspirator exception. In the first challenged statement, Robert Meyer, a frequent customer at the Ke-nosha club, testified about a conversation between himself and Mr. Pixley in which the two discussed a red curtain at one of the clubs. Meyer testified that Mr. Pixley “mentioned that when he was hired back there that Josephine had a curtain put up in the terrace or the patio area, how ridiculous it was, it was asking for problems with the police.” Tr. at 720. In the second challenged statement, John Patrick Doerr, Dale Doerr’s half brother, testified that, in a conversation with his brother, Dale had laughed at him and said “I can’t believe — I don’t believe — I can’t believe you don’t know what’s going on, or you didn’t know what’s going on.” Tr. at 999. While conceding that these two statements may have been admissible against their declarants, Mr. Pixley and Dale Doerr, the appellants maintain that they should not have been admitted against the nondeclarant appellants because the statements were not made “in furtherance” of the conspiracy. Thus, they contend, Rule 801(d)(2)(E) was not satisfied. We recently emphasized that the “in furtherance” requirement of Rule 801(d)(2)(E) is a limitation on the admissibility of coconspirators’ statements that is meant to be taken seriously. See Garlington v. O’Leary, 879 F.2d 277, 283 (7th Cir.1989). As we explained in Garlington, a coeonspirator’s statement satisfies the “in furtherance” requirement “when the statement is ‘part of the information flow between conspirators intended to help each perform his role.’ ” Id. (quoting United States v. Van Daal Wyk, 840 F.2d 494, 499 (7th Cir.1988)). We further explained that statements “in furtherance” of a conspiracy can take many forms, including statements made to recruit potential coconspirators, statements seeking to control damage to an ongoing conspiracy, statements made to keep eoconspirators advised as to the progress of the conspiracy, and statements made in an attempt to conceal the criminal objectives of the conspiracy. Id. Narrative declarations, mere “idle chatter,” and superfluous casual conversations, however, are not statements “in furtherance” of a conspiracy. See id.] see also United States v. Foster, 711 F.2d 871, 880 (9th Cir.1983) (mere narrative declarations, made without intent to induce assistance to the conspiracy, do not satisfy the “strict requirements” of Rule 801), cert. denied, 465 U.S. 1103, 104 S.Ct. 1602, 80 L.Ed.2d 132 (1984); United States v. Lieberman, 637 F.2d 95, 102 (2d Cir.1980) (challenged testimony “smack[ed] of nothing more than casual conversation about past events. It is difficult to envision how it would have furthered the conspiracy.”). A district court's finding that a particular statement was made “in furtherance” is reviewed under a clearly erroneous standard. United States v. Shoffner, 826 F.2d 619, 627-28 (7th Cir.), cert. denied, 484 U.S. 958, 108 S.Ct. 356, 98 L.Ed.2d 381 (1987). In addition, a court may conclude that the challenged statement was “in furtherance” even though “ ‘the statement [was] susceptible of alternative interpretations.’ ” Id. at 628 (quoting United States v. Mackey, 571 F.2d 376, 383 (7th Cir.1978)). Moreover, the “in furtherance” requirement is satisfied so long as “ ‘some reasonable basis exists for concluding that the statement furthered the conspiracy.’ ” Id., quoted in Garlington, supra, at 283. The government contends that the district court had a reasonable basis for concluding that Mr. Pixley’s statements, described at trial by Meyer, were made “in furtherance” of the conspiracy. The government explains that, in addition to being a frequent customer, Robert Meyer had an interest in investing in the Kenosha club. Given this interest, the government asserts that “the trial court had a ‘reasonable basis’ for concluding that Pixley’s comments were made in furtherance of the conspiracy since Pixley and Meyer had an interest in discussing ways that the club could improve and remain in operation.” Government Br. at 19. The government also contends that Dale Doerr’s statement was “in furtherance” of the conspiracy, because it was a description of the clubs’ illegal activities to John Patrick Doerr, a coeonspirator who worked at the clubs as a manager and doorman. We cannot accept the government's contentions. Therefore, we conclude that the district court erred in admitting the challenged testimony. Neither Mr. Pixley’s statement nor Dale Doerr’s statement was made “in furtherance” of the conspiracy. After reviewing Robert Meyer’s testimony, we conclude that Mr. Pixley’s discussion of the red curtain with Meyer cannot reasonably be characterized as part of an attempt to induce Meyer to join or assist the conspiracy. Instead, the statements are more accurately characterized as a narrative discussion of a past event. As such, they do not satisfy the “in furtherance” requirement of Rule 801(d)(2)(E). Similarly, Dale Doerr’s statement to John Patrick Doerr fails to satisfy the “in furtherance” requirement. In making the statement recounted by John Patrick Doerr at trial, Dale was mocking his half-brother’s ignorance of the clubs’ unlawful activities; such a statement cannot be characterized as part of the normal information flow between coconspirators and in no way furthered the ends of the conspiracy. Thus, neither Mr. Pixley’s statement nor Dale Doerr’s statement should have been admitted under Rule 801(d)(2)(E). The improper admission of these statements, however, does not constitute reversible error. Nonconstitutional errors, like the evidentiary errors in this case, are governed by the harmless error standard of Rule 52(a) of the Federal Rules of Criminal Procedure. “Any error, defect, irregularity or variance which does not affect substantial rights shall be disregarded.” Fed.R.Crim.P. 52(a); United States v. York, 852 F.2d 221, 226 n. 3 (7th Cir.1988). “Only if we are convinced that the error did not influence the jury or had only a very slight effect, and can so say with fair assurance, should we hold the error as harmless.” United States v. Zapata, 871 F.2d 616, 622 (7th Cir.1989); see also United States v. Grier, 866 F.2d 908, 920 (7th Cir.1989) (where the error has had “no ‘substantial influence on the verdict,’ ” reversal is not warranted) (quoting United States v. Kotteakos, 328 U.S. 750, 765, 66 S.Ct. 1239, 1248, 90 L.Ed. 1557 (1946)). We are convinced that the erroneous admission of the challenged statements in this case had no substantial influence on the jury’s verdict. Witnesses other than Meyer testified that they knew that Ms. Christofalos had been involved in the placement of a curtain in the rear of the clubs. Similarly, Dale Doerr’s statement to his brother was hardly the only testimony showing that unlawful activity was obvious at the clubs; many witnesses testified that the appellants knew prostitution was occurring at the clubs and massage parlor. We therefore conclude that the district court’s erroneous admission of the challenged hearsay statements was harmless. 2. Admission of Anthony Barbaro’s grand jury testimony On May 25, 1982, Anthony Barbaro, who had been employed at the massage parlor in 1981, testified before a grand jury investigating this case. Barbaro told the grand jury that prostitution had been going on at the massage parlor and that he had deposited cash from the massage parlor in the bank account of St. Michael’s Southern Catholic Church (a church established by John Paul Doerr), using deposit slips made out by John Paul Doerr or Dale Doerr. Just prior to trial, the district court granted the government’s motion for formal immunity for Barbaro during the trial. During the immunity hearing on November 13, 1987, however, Barbaro stated that he would not testify. On November 23, 1987, Barbaro’s counsel again stated that he would not testify. The United States called Barbaro as a witness on November 25. He refused to testify, and both the government and the district court reminded him of his immunity and warned him that he was subjecting himself to both civil and criminal contempt. Barbaro again refused to testify and stated, “[h]ow many times we got to go through this? I am not testifying.” Tr. at 618. The court ordered Barbaro to answer the question posed by the government and asked, “[a]re you refusing or are you going to?” Id. Barbaro responded, “I have said it twice already.” Id. The court then found Barbaro to be in civil contempt and ordered that he be confined until he was willing to testify. On November 29, 1987, the district court issued a written order advising Barbaro that he could purge himself of his contempt by testifying and telling him that, should he change his mind, he should inform the court immediately of his willingness to testify. See J.P. Doerr R.66. At no point during the trial did Barbaro inform the court of his willingness to testify. He ultimately was held in criminal contempt and sentenced to 18 months’ imprisonment. On November 25, the government had asked the court to declare Barbaro unavailable for trial. The court reserved ruling on this matter pursuant to defense counsels’ request for more time to study the issue. On December 16, 1987, the court, over the defendants’ objection, permitted the government to introduce portions of Barbara's grand jury testimony. As noted above, Barbaro at no time informed the court of his willingness to testify. See J.P. Doerr R.176. On appeal, the appellants maintain that introduction of Barbara’s grand jury testimony was improper under both Rule 804(b)(5) of the Federal Rules of Evidence (the catch-all hearsay exception) and the confrontation clause of the sixth amendment, because Barbaro was not shown to be unavailable on the day that his grand jury testimony was presented to the jury and no other evidence corroborated the substance of his testimony. John Paul Doerr asserts that the district court made an “anticipatory” ruling that Barbaro was unavailable when it simply concluded that, because Barbaro had previously refused to testify, he would not testify at any point in the future. The court’s determination that Barbaro was unavailable was, therefore, improper, since the court failed to inquire at the time the grand jury testimony was to be used whether or not the witness was still recalcitrant. See J.P. Doerr Br. at 6-7. a. Rule 804(b)(5) In order for a hearsay statement to be admissible under Rule 804(b)(5), the proponent of the statement must show that the declarant is unavailable and that the statement contains “ ‘circumstantial guarantees of trustworthiness’ equivalent to those inherent in the more specific exceptions provided under Rule 804(b)(l)-(4).” United States v. Snyder, 872 F.2d 1351, 1354 (7th Cir.1989). We review the district court’s decision that a particular hearsay statement is admissible under Rule 804 only for an abuse of discretion. See id.; see also United States v. Fuesting, 845 F.2d 664, 673 (7th Cir.1988) (“We will reverse a district court’s evidentiary ruling only where there has been a clear abuse of [the court’s broad] discretion.”). We shall turn first to unavailability and then address the “circumstantial guarantees of trustworthiness” supporting admission of Barbaro’s grand jury testimony. i. unavailability. Rule 804 provides that unavailability as a witness includes situations in which the declarant “persists in refusing to testify concerning the subject matter of the declarant’s statement despite an order of the court to do so.” Fed.R.Evid. 804(a)(2). The government contends that, since Barbaro had repeatedly refused to testify and had not notified the court of his willingness to testify pursuant to its November 29 order, the appellants’ assertion that Barbaro had not been shown to be unavailable on the day his grand jury testimony was introduced is meritless. The district court did not err in concluding that Barbaro was unavailable as a witness for the purposes of Rule 804(b)(5). Barbaro repeatedly refused to testify despite a grant of immunity and the threat of contempt sanctions. He was directly ordered by the court to answer the government’s questions and refused to do so. He was then held in civil contempt and ordered confined until he was willing to testify. Moreover, he was explicitly informed that if he testified he would be purged of his contempt and that he should immediately inform the court if he should change his mind. The court never received notice from Barbaro of any decision to testify. Under these circumstances, Barbaro’s persistence had been adequately tested, see United States v. Boulahanis, 677 F.2d 586, 588 (7th Cir.), cert. denied, 459 U.S. 1016, 103 S.Ct. 375, 74 L.Ed.2d 509 (1982), and the court properly concluded that the unavailability requirement of the rule had been satisfied. Mr. Doerr’s assertion, accompanied by citation to United States v. Johnson, 736 F.2d 358 (6th Cir.1984), that the district court erroneously anticipated Barbaro’s refusal to testify without giving him a chance to change his mind, see J.P. Doerr Br. at 6, is unfounded. The district court in Johnson improperly held a witness in civil contempt merely because, at a pretrial hearing before any order to testify had been imposed, the witness stated that he intended to refuse to testify. 736 F.2d at 359-60. No actual refusal to testify had occurred and the trial itself had not even started. In contrast, Barbaro had actually refused to testify, had properly been held in civil contempt for doing so, and had explicitly been given, by court order, an open invitation to change his mind. Thus, Barbaro was “unavailable” as defined in Rule 804 — he obstinately had persisted in his refusal to testify despite a court order to do so. Requiring the government to bring Barbaro back into court on December 16 solely so that he could refuse to testify once more would have served little purpose. ii. circumstantial guarantees of trustworthiness. As noted above, in addition to demonstrating unavailability, Rule 804(b)(5) requires that a hearsay statement not covered by some other exception be supported by “equivalent circumstantial guarantees of trustworthiness” before it can be admitted. A trial judge has “ ‘considerable discretion’ ” in determining whether “ ‘hearsay statements contain the necessary circumstantial guarantees of trustworthiness’ ” to be admissible under the federal rules. See United States v. Guinan, 836 F.2d 350, 354 (7th Cir.), cert. denied, — U.S.-, 108 S.Ct. 2871, 101 L.Ed.2d 907 (1988) (quoting United States v. Vretta, 790 F.2d 651, 659 (7th Cir.), cert. denied, 479 U.S. 851, 107 S.Ct. 179, 93 L.Ed.2d 115 (1986)). The factors that should be considered by the district court in assessing the trustworthiness of hearsay testimony include: the character of the witness for truthfulness and honesty, and the availability of evidence on the issue; whether the testimony was given voluntarily, under oath, subject to cross-examination and a penalty for perjury; the witness’ relationship with both the defendant and the government and his motivation to testify before the grand jury; the extent to which the witness’ testimony reflects his personal knowledge; whether the witness ever recanted his testimony; the existence of corroborating evidence; and, the reasons for the witness’ unavailability. Snyder, 872 F.2d at 1355-56. This list of factors is neither exhaustive nor absolute, and each case must be analyzed on its own facts. Id.; United States v. York, 852 F.2d 221, 225 (7th Cir.1988); United States v. Hooks, 848 F.2d 785, 797 (7th Cir.1988); Guinan, 836 F.2d at 355. Our review of the record reveals that a number of the factors supporting admissibility are present in this case. For example, although Barbaro’s grand jury testimony was not subject to cross-examination, it was given under oath and subject to a penalty for perjury. Barbaro was explicitly informed that he had a constitutional right not to answer any question that he chose not to answer, he acknowledged that he had been placed under oath, and he recognized that perjury is a felony. See Tr. at 2712-14. More importantly, there is no indication that Barbaro was pressured to testify. See Boulahanis, 677 F.2d at 588. Indeed, he testified before the grand jury voluntarily; he had not been granted any form of immunity at that time. See Tr. at 2713. Because Barbaro’s testimony was not given under a grant of immunity, he exposed himself to potential criminal liability for the distribution of funds generated by prostitution. See 18 U.S.C. § 1952(a)(1). Thus, his grand jury testimony has the circumstantial guarantee of trustworthiness supporting the hearsay exception for statements against interest. See Fed.R.Evid. 804(b)(3) advisory committee’s note (“The circumstantial guaranty of reliability for declarations against interest is the assumption that persons do not make statements which are damaging to themselves unless satisfied for good reason that they are true.”). In addition, Barbaro’s testimony was based entirely on his own personal knowledge — he revealed what he saw on the job and what his duties were as a security guard at the Kenosha massage parlor. See Snyder, 872 F.2d at 1356. Moreover, the appellants have not identified any incentive to manufacture false testimony that Barbaro may have had. See Guinan, 836 F.2d at 355; see also Hooks, 848 F.2d at 797 (“Another indicium of reliability is the declarant’s disinterest; the testimony of a ‘mere bystander with no axe to grind’ tends to be more trustworthy.”) (quoting Boulahanis, 677 F.2d at 588); United States v. Howard, 774 F.2d 838, 845 (7th Cir.1985) (statements made by a “seemingly disinterested witness under circumstances that created no apparent motive to lie”). While Barbaro has been convicted of second-degree murder, the jury was apprised of his conviction before his testimony was placed in evidence. Certain aspects of Barbaro’s testimony are also corroborated by other evidence introduced at trial. For example, IRS Special Agent Gerald Ontko testified that St. Michael’s Church did maintain a bank account in Kenosha and that the bulk of the deposits into that account were made in cash. See Tr. at 2562-63; Government Ex. 353-C (73% of deposits made in currency). In addition, the account’s signature card was signed in the name of the “Rev. James Jackson.” See Government Ex. 353-A. This was a name that Barbaro testified he knew John Paul Doerr used. See R. 178 at 5 (Tr. of Barbaro Grand Jury Testimony). The government also presented documentary evidence of a deposit slip initialed by “DJD” (Dale J. Doerr), indicating a cash deposit into the account of St. Michael’s Church. Government Ex. 353-B at 28. John Paul Doerr himself also admitted on cross-examination that the deposit slips showing cash deposits into the St. Michael’s account were made in his handwriting. See Tr. at 3732-34. Further, Barbara's testimony that he deposited cash from the massage parlor into a church account is consistent with the evidence that John Paul Doerr laundered other prostitution-related funds through the Holy Temple of Christ the Redeemer Church. See Tr. at 2500-19. Finally, many witnesses corroborated Barbara's testimony that prostitution occurred in the massage parlor. The appellants maintain that “crucial points” of Barbara’s testimony were not corroborated. Joint Br. at 24. However, “a court cannot require that every detail of an item of hearsay testimony be corroborated before admitting it under Rule 804(b)(5).” Guinan, 836 F.2d at 357; see also Snyder, 872 F.2d at 1356 (“While Snyder did not confirm every detail of Barton’s testimony, he conceded enough to make the whole adequately trustworthy.”). Because Barbara’s grand jury testimony did contain adequate “circumstantial guarantees of trustworthiness,” we conclude that the district court did not abuse its discretion under Rule 804(b)(5) in allowing this testimony to be presented to the jury. b. Confrontation clause Although the hearsay rules and the confrontation clause “stem from the same root, ... the two are not equivalent.” Vretta, 790 F.2d at 660 (quoting Dutton v. Evans, 400 U.S. 74, 86, 91 S.Ct. 210, 218, 27 L.Ed.2d 213 (1970)). Therefore, evidence that is admissible under the catch-all hearsay exception may still violate the sixth amendment. See Guinan, 836 F.2d at 358; see also Snyder, 872 F.2d at 1355 (“The standards are similar, yet distinct, and reliability may not be inferred under a Sixth Amendment analysis merely because the prior testimony is admissible under Rule 804(b)(5).”) (citations omitted). We have explained that, in order to defeat a constitutional challenge to admissibility, the challenged statement must be supported by “ ‘adequate indicia of reliability to justify the placement of the hearsay statement before the jury.’ ” Guinan, 836 F.2d at 358 (quoting United States v. Feldman, 761 F.2d 380, 387 (7th Cir.1985)); see also Ohio v. Roberts, 448 U.S. 56, 65-66, 100 S.Ct. 2531, 2538-39, 65 L.Ed.2d 597 (1980); Snyder, 872 F.2d at 1354. Even where there has been no opportunity for cross-examination, a statement’s admission is not constitutionally barred if the government has demonstrated the unavailability of the witness and has “ ‘made a strong “showing of particularized guarantees of trustworthiness” concerning the statements.’ ” Guinan, 836 F.2d at 358 (quoting United States v. Howard, 774 F.2d 838, 846 (7th Cir.1985) (quoting Roberts, 448 U.S. at 66, 100 S.Ct. at 2539)); Vretta, 790 F.2d at 660. This court has developed a two-part test based on Roberts: statements are constitutionally admissible even in the absence of cross-examination “ ‘if it is clear (1) that the declarant actually made the statement in question; and (2) there is circumstantial evidence supporting its veracity.’ ” Guinan, 836 F.2d at 358 (quoting Feldman, 761 F.2d at 387). The first requirement is clearly met in this case — the challenged evidence consists of excerpts of a grand jury transcript and no challenge to the accuracy of the transcript has been made. Thus, there is no question that Barbaro actually made the statements in question. See id. at 358. Moreover, in light of our previous discussion of the particular circumstantial guarantees of trustworthiness contained in Barbara’s testimony, we conclude that the second requirement is satisfied as well. Therefore, we reject the appellants’ contention that admission of Barbaro’s grand jury testimony violated their rights under the confrontation clause of the sixth amendment. 3. Admission of charts into evidence The appellants next argue that they were denied a fair trial because the government was allowed to introduce an “overwhelming number” of enlarged charts that were merely cumulative of documentary evidence already presented to the jury. They contend that these charts were more prejudicial than probative. Thus, the charts should have been excluded under Rule 403 of the Federal Rules of Evidence. Sixty-one charts showing the relationships between hundreds of separate documentary exhibits were introduced by the government. The appellants maintain that “[t]he massive quantity of the government charts unfairly emphasized the government’s evidence and gave the government’s theories a life of their own.” Joint Br. at 27. This argument is without merit. We have explained that the decision to admit “summary charts is within the trial court’s discretion, and will be reversed only for an abuse of that discretion.” United States v. Howard, 774 F.2d 838, 844 (7th Cir.1985); see also United States v. Lamp, 779 F.2d 1088, 1094 (5th Cir.1986) (no abuse of discretion in allowing the government to use charts and summaries in complex tax evasion case), cert. denied, 476 U.S. 1144, 106 S.Ct. 2255, 90 L.Ed.2d 700 (1986). No abuse of discretion has been shown in this case. The district court reviewed the charts with some care, and concluded that “the charts [were] more helpful to the jury than sheets of paper.” See Tr. at 2808. Because there were a number of separate transactions involved in the money-laundering scheme alleged in Count Two of the indictment, and scores of deposit slips and cancelled checks were submitted as documentary evidence, this was a reasonable conclusion. In addition, the court instructed the jury on the function of the charts as summaries. The court informed the jury that the charts were not themselves evidence or proof of any facts and instructed them to disregard the charts if they concluded that the charts did not correctly reflect the facts shown by the evidence. This instruction was consistent with our explanation in Howard that, when the trial court authorizes the use of charts as a teaching device rather than as substantive evidence, “the preferred practice would be for the court to give a limiting instruction regarding this purpose.” 774 F.2d at 844 n. 4. Thus, under the circumstances of this case, the court’s decision to allow the government to introduce a number of summary charts was not an abuse of discretion. 4. Refusal to strike testimony of Mary Patton Marino Mary Marino testified at trial that the promotion of prostitution at the clubs was discussed and acknowledged at the management level. On December 3, 1987, during a voir dire examination before she testified as a government witness, see Tr. at 1492, Ms. Marino denied that she had been charged with theft in Illinois in 1980, denied any memory of the theft charges, and denied ever appearing in court with respect to the theft charges. Illinois court documents, however, confirmed that Ms. Marino had in fact been charged with theft in 1980. Ms. Marino was not questioned about these charges during her direct examination or cross-examination as a government witness. Nor was any objection to Ms. Marino’s testimony made at the conclusion of her appearance as a government witness on December 4. On December 8, however, defense counsel moved for a mistrial or, in the alternative, to strike Ms. Marino’s testimony. The district court denied these motions. On December 22, Ms. Marino again testified, this time as a witness for Mr. Pixley. In the presence of the jury, defense counsel confronted her with certified Illinois court records confirming the theft charges against her. She persisted in denying the charges and claimed not to remember appearing in court. See Tr. at 3621-25. After extensive examination, she ultimately conceded that the documents did say she had been indicted. She claimed, however, that the indictment “had nothing to do with [her].” Tr. at 3634. The appellants (with the exception of Dale Doerr who expressly declined to join the other appellants’ motion to strike) now argue that the district court erred in failing to strike Ms. Marino’s testimony. They maintain that her “evasiveness and persistent refusal to acknowledge what was clearly the truth call into question her entire testimony.” Joint Br. at 29. Because her testimony was shown to be so “inherently unreliable” that there was a substantial likelihood that it was false, the appellants contend that the district court’s refusal to exclude her testimony constitutes reversible error. We disagree. The appellants purport to rely primarily on two cases, Manson v. Brathwaite, 432 U.S. 98, 97 S.Ct. 2243, 53 L.Ed.2d 140 (1977), and Neil v. Biggers, 409 U.S. 188, 93 S.Ct. 375, 34 L.Ed.2d 401 (1972), holding that the due process clause requires the exclusion of identification evidence based on impermissibly suggestive procedures. See Christofalos Reply Br. at 4-5 (citing Joint Br. at 5). These precedents have little relevance to the case at hand. Unlike improperly obtained identifications, the flaws in Ms. Marino’s testimony were readily apparent to the jury. By introducing the Illinois court records into evidence and confronting Ms. Marino with those records in the presence of the jury, defense counsel were given an opportunity to undermine effectively Ms. Marino’s credibility. Moreover, defense counsel were able to impress upon the jury during their closing arguments that Ms. Marino’s testimony had been seriously impeached. See Tr. at 3986-87, 4023, 4031, 4035. It is, of course, the function of the jury to make credibility resolutions, see United States v. Vega, 860 F.2d 779, 794 (7th Cir.1988); United States v. Dorn, 561 F.2d 1252, 1257 (7th Cir.1977) (“it is the function of the jury and not a reviewing court ... to judge the credibility of witnesses”); Seifert v. Solem, 387 F.2d 925, 928 (7th Cir.1967), and the jury in this case had sufficient evidence before it to decide for itself whether Ms. Marino was a credible witness. Under these circumstances, the district court did not err in refusing to strike Ms. Marino’s testimony. 5. Improper instructions on Count One In its jury instructions on Count One of the indictment, the district court read to the jury several Wisconsin and Illinois statutes defining a number of prostitution-related offenses. The appellants maintain that, because a prosecution under section 1952(a) does not require actual proof of a violation of state law, instructing the jurors with these statutes only served to confuse them. Such confusion allegedly arose from the fact that each statute read to the jury contains its own intent element, while the government was required to prove intent to conspire to violate section 1952. In addition, the court read to the jury a new Illinois prostitution statute that did not become effective until July 1, 1984. While the conspiracy charged in Count One allegedly lasted from 1979-1987, the appellants maintain that reading this statute to the jury was error because there was no allegation in the indictment and no proof at trial that any acts of prostitution were attempted or committed in Illinois after the effective date of the new Illinois statute. We reject these objections to the jury instructions. The standard of review applied to challenges to jury instructions is well established: “ ‘The question of whether a jury has been properly instructed is to be determined not upon consideration of a single paragraph, sentence, phrase or word, but upon the charge as a whole.’ ” United States v. Alexander, 743 F.2d 472, 478 (7th Cir.1984) (quoting United States v. Lang, 644 F.2d 1232, 1240 (7th Cir.), cert. denied, 454 U.S. 870, 102 S.Ct. 338, 70 L.Ed.2d 174 (1981)); see also United States v. Bailey, 859 F.2d 1265, 1277 (7th Cir.1988) (must view jury charge as a whole, rather than focusing on isolated passages), cert. denied, — U.S. -, 109 S.Ct. 796, 102 L.Ed.2d 787 (1989). So long as “ ‘the instructions treat the issues fairly and accurately,’ ” they will not be disturbed on appeal. United States v. Thibodeaux, 758 F.2d 199, 202 (7th Cir.1985) (quoting United States v. Croft, 750 F.2d 1354, 1366 (7th Cir.1984)); see also General Leaseways, Inc. v. National Truck Leasing Ass’n, 830 F.2d 716, 725 (7th Cir.1987). (jury instructions must be construed in a “ ‘common sense manner, avoiding fastidiousness, inquiring whether the correct message was conveyed to the jury reasonably well’ ”) (quoting Wilk v. American Medical Ass’n, 719 F.2d 207, 218 (7th Cir.1983), cert. denied, 467 U.S. 1210, 104 S.Ct. 2398, 81 L.Ed.2d 355 (1984)). As the appellants correctly note, we have held that section 1952 does not incorporate state law as part of the federal offense: “[t]he federal crime is the use of the interstate facilities in furtherance of the unlawful activity, not the violation of state law.” United States v. Peskin, 527 F.2d 71, 79 n. 3 (7th Cir.1975), cert. denied, 429 U.S. 818, 97 S.Ct. 63, 50 L.Ed.2d 79 (1976). Section 1952, however, does refer to state law in order to identify the unlawful activity in which the defendant is engaged. Id. (citing United States v. Rizzo, 418 F.2d 71, 74 (7th Cir.1969), cert. denied, 397 U.S. 967, 90 S.Ct. 1006, 25 L.Ed.2d 260 (1970)). Including the state statutes in the jury instructions in this case served this legitimate descriptive purpose — the statutes provided the jury with a description of the unlawful activity in which the appellants allegedly engaged. We cannot fault the district court for providing the jury with the entire range of applicable statutes. The instructions, read as a whole, permitted the jury to assess the facts accurately and comprehensively. We cannot accept the argument that mention of the 1984 Illinois statute necessarily suggested that acts of prostitution had taken place after its passage. Indeed, because of its comprehensiveness, the instruction also informed the jury precisely what was forbidden when the Illinois-based establishment was in operation. Moreover, the likelihood of jury confusion with regard to the intent element that the government actually was required to prove appears to be quite slim. Indeed, such a possibility is pure speculation. We believe that the instructions, read as a whole, reasonably and accurately informed the jury of the intent requirement under section 1952(a) and did not mislead the jury with respect to the applicable time frames. The appellants were charged with conspiring to violate 18 U.S.C. § 1952. The jury was instructed that the government must prove that the defendant knowingly and intentionally became a member of the conspiracy. See Tr. at 4159. In addition, the jury received specific instructions detailing the essential elements of a section 1952 violation, including the intent element. See Tr. at 4164. The court also informed the jury that the definition of “unlawful activity” under section 1952 includes “any business enterprise involving prostitution in violation of the laws of the state in which they are committed.” Tr. at 4165 (emphasis supplied). Only after giving these specific instructions did the court read the state prostitution statutes to the jury. No special attention was drawn to the intent elements of these statutes. See Tr. at 4171-75. Thus, the instructions accurately informed the jury of the applicable law. When the instructions are viewed in their entirety, we conclude that there is no merit in the appellants’ challenge to the instructions given the jury. B. Issues Raised by Josephine Christofalos 1. Government use of “off-the-record” statements Before her arrest, Ms. Christofalos was interviewed by government agents on February 4, 1987. At that time, she was represented by court-appointed counsel who assured her that any statements she gave to the agents would be “off-the-record” and could not be used against her. Her attorney’s advice was based on his belief that he had an agreement with the government prosecutor that her statements would be off-the-record. Ms. Christofalos moved to suppress any statements (and any “fruits” of the statements) obtained during the February 4 interview and sought dismissal of the indictment against her. At the suppression hearing, however, the prosecutor testified that no off-the-record agreement had been made. The magistrate conducting the suppression hearing found that there was no agreement between the government and Ms. Christofalos’ counsel that the February 4 interview was to be off-the-record. The magistrate also found that no coercive governmental conduct, deception, or overreaching had occurred in this case. The magistrate therefore concluded that Ms. Christofalos’ statements were voluntary and should not be suppressed. The district court adopted the magistrate’s findings of fact and conclusions of law and denied Ms. Christofalos’ motion to suppress. On appeal, Ms. Christofalos does not challenge the district court’s conclusion that her statements at the February 4 interview were voluntary. See Chris-tofalos Br. at 7 (“voluntariness is not in issue”). Neither does she challenge the district court’s findings of fact. See id. (“Ms. Christofalos does not ask this Court to disturb those findings of historical fact.”). At trial, part of the government’s questioning of Ms. Christofalos stemmed from statements obtained during the February 4 interview, and Ms. Christofalos believes that some statements made during the interview were presented to the grand jury. She contends that government use of the statements violated her constitutional rights, because, at the February 4 interview, she had not knowingly and intelligently waived her fifth amendment privilege against self-incrimination. See Chris-tofalos Br. at 7. Thus, she concludes that any statements obtained during the interview should have been suppressed and she should have been permitted to determine whether any statements from the interview had been presented to the grand jury. We reject Ms. Christofalos’ contention on two grounds. First, in light of the unchallenged findings of the district court, we cannot say that Ms. Christofalos’ February 4 statements were obtained in violation of her fifth amendment right to be free from compelled self-incrimination. In addition, even assuming that her statements were obtained in violation of the fifth amendment, use of those statements at trial and before the grand jury did not constitute reversible error. a. The fifth amendment provides in relevant part that “[n]o person ... shall be compelled in any criminal case to be a witness against himself.” U.S. Const, amend. V (emphasis supplied). Thus, by its own terms, the fifth amendment only protects criminal defendants from compulsory self-incrimination. As the Supreme Court has repeatedly explained, “the Fifth Amendment is limited to prohibiting the use of ‘physical or moral compulsion’ exerted on the person asserting the privilege.” Fisher v. United States, 425 U.S. 391, 397, 96 S.Ct. 1569, 1574, 48 L.Ed.2d 39 (1976). Thus, where a defendant’s incriminating statements were wholly voluntary and were not the “product of any sort of coercion, legal or factual[,] ... it is clear that no right protected by the Fifth Amendment privilege against compulsory self-incrimination [has been] violated.” Hoffa v. United States, 385 U.S. 293, 304, 87 S.Ct. 408, 414, 17 L.Ed.2d 374 (1966). Because the uncontested facts in this case reveal that Ms. Christofalos’ presence at the February 4 interview was wholly voluntary and her statements were not the product of any coercive governmental conduct, Ms. Chris-tofalos has failed to demonstrate any violation of her fifth amendment rights. b. i. use of statements at trial. Even if Ms. Christofalos’ right against self-incrimination was violated, we are confident, beyond a reasonable doubt, that she suffered no prejudice at trial. Ms. Christo-falos points to only one instance in this lengthy trial in which the government used any information derived from the February 4 interview. See Christofalos Br. at 5. On December 18, the government asked Ms. Christofalos several questions about an employee known as “Big Mouth Mike” allegedly based on information discussed during the interview. Tr. at 3133-34. No objection was made to the line of questioning at that time. Four days later, defense counsel moved that the testimony be stricken. Tr. at 3508. After characterizing the dispute as a “tempest in a teapot,” Tr. at 3510, the court granted the motion to strike. The court noted that the challenged testimony had not “one iota of probative value.” Tr. at 3511. The court also explicitly informed the jury that the “Big Mouth Mike” testimony had been stricken and instructed them to disregard any reference to “Big Mouth Mike.” Tr. at 3919. We are confident that any potential constitutional violation growing out of the government’s trial use of information stemming from the February 4 interview was clearly harmless beyond a reasonable doubt. See Delaware v. Van Arsdall, 475 U.S. 673, 681, 106 S.Ct. 1431, 1436, 89 L.Ed.2d 674 (1986); Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 828, 17 L.Ed.2d 705 (1967). ii. presentation of statements to the grand jury. Ms. Christofalos’ claim that the district court committed reversible error by denying her motion to dismiss the indictment and refusing to allow her to explore whether any statements from the February 4 interview had been presented to the grand jury is also without merit. Even if we assume, arguendo, that Ms. Christofalos’ right against self-incrimination was violated, the Supreme Court has explained that “[a]n indictment returned by a legally constituted and unbiased grand jury ..., if valid on its face, is enough to call for a trial on the merits.” Costello v. United States, 350 U.S. 359, 363, 76 S.Ct. 406, 409, 100 L.Ed. 397 (1956) (footnote omitted). In Costello, the Court held that an indictment based entirely on incompetent evidence — hearsay—need not be quashed. Id. The Court’s reluctance to examine the quality or sufficiency of the evidence presented to a grand jury extends even to unconstitutionally obtained evidence: The grand jury’s sources of information are widely drawn, and the validity of an indictment is not affected by the character of the evidence considered. Thus, an indictment valid on its face is not subject to challenge on the ground that the grand jury acted on the basis of inadequate or incompetent evidence, Costello v. United States, supra; Holt v. United States, 218 U.S. 245 [31 S.Ct. 2, 54 L.Ed. 1021] (1910); or even on the basis of information obtained in violation of a defendant’s Fifth Amendment privilege against self-incrimination, Lawn v. United States, 355 U.S. 339 [78 S.Ct. 311, 2 L.Ed.2d 321] (1958). United States v. Calandra, 414 U.S. 338, 344-45, 94 S.Ct. 613, 618-19, 38 L.Ed.2d 561 (1974); see also Midland Asphalt Corp. v. United States, — U.S.-, 109 S.Ct. 1494, 1499, 103 L.Ed.2d 879 (1989) (“even the grand jury’s violation of the defendant’s right against self-incrimination does not trigger the Grand Jury Clause’s ‘right not to be tried.’ ”); United States v. Blue, 384 U.S. 251, 255 & n. 3, 86 S.Ct. 1416, 1419 & n. 3, 16 L.Ed.2d 510 (1966) (even if government presented to grand jury evidence acquired in violation of the fifth amendment, “our precedents indicate this would not be a basis for abating the prosecution pending a new indictment, let alone barring it altogether”) (citing Costello and Lawn); 2 W. LaFave & J. Israel, Criminal Procedure § 15.4(a) at 303 (1984). In light of these principles, the validity of Ms. Christofalos’ indictment cannot be challenged on the basis of her suspicion that statements obtained in violation of the fifth amendment were presented to the grand jury. Thus, Ms. Christofalos’ contention that the district court committed reversible error by refusing to explore the evidence presented to the grand jury must be rejected. 2. Pre-indictment delay Ms. Christofalos maintains that an unwarranted five-year pre-indictment delay deprived her of her constitutional right to timely indictment by a grand jury and notice of the charges against her. She asserts that the delay prevented her from presenting witnesses helpful to her defense because, by the time of trial, those witnesses were either dead or could not be located. She maintains that the focus of the indictment was on events occurring between 1980 and 1982 and she asserts that she was severely prejudiced by the fact that an indictment was not returned until 1987. The district court rejected this argument and refused to dismiss the indictment against Ms. Christofalos. See Christofalos R. 61 at 6-7; Tr. at 3511-14. Although statutes of limitation provide the “primary guarantee” against prosecutorial delay, the Supreme Court has explained that “the Due Process Clause has a limited role to play in protecting against oppressive delay.” United States v. Lovasco, 431 U.S. 783, 789, 97 S.Ct. 2044, 2048, 52 L.Ed.2d 752 (1977). When considering whether the due process clause of the fifth amendment requires the dismissal of an indictment on the ground of undue pre-indictment delay, we must engage in a two-step inquiry. First, the defendant must prove that she suffered actual and substantial prejudice. Second, the court must weigh the actual prejudice to the defendant against the government’s reasons for the delay. Prejudice for the purposes of this analysis is difficult to prove; the defendant must point quite specifically to how she was prejudiced, and the defendant’s showing must be concrete, not speculative. “A defendant must do more than allege that a particular witness is no longer available and that the witness’s testimony would have helped the defense.” United States v. Antonino, 830 F.2d 798, 805 (7th Cir.1987). Moreover, we shall only conclude that the death of a witness has prejudiced a defendant where we are “ ‘convinced that [the witness] would have testified, that his testimony would have withstood cross-examination, and that the jury would have found [him] a credible witness.’ ” United States v. Valona, 834 F.2d 1334, 1339 (7th Cir.1987) (quoting United States v. Williams, 738 F.2d 172, 176 (7th Cir.1984)). Further, even if we are convinced that an absent witness would have been a credible witness for the defendant, “we must still evaluate this testimony against the other trial evidence to determine if indeed its introduction would affect the trial outcome.” Id. We cannot accept Ms. Christofalos’ undue delay argument. She has failed to make the requisite showing of actual and substantial prejudice. She quite frankly admits that she has no “in-depth knowledge about what the vanished witnesses or the dead witnesses could say” and she does not state how exculpatory their testimony might be. She does not even know the names of many of the witnesses that she claims would have come to her aid had the indictment been brought in 1982. See Christofalos Br. at 18. We do not know whether these potential witnesses would in fact have testified, whether their testimony would have withstood cross-examination, or whether the jury would have found them credible. Under these circumstances, Ms. Christofalos has failed to establish prejudice. See Valona, 834 F.2d at 1339; An-tonino, 830 F.2d at 806. We therefore conclude that the district court did not err in refusing to dismiss the indictment because of impermissible pre-indictment delay. 3. Restricted admission of IRS Special Agent’s Report In an investigation separate from that leading to the indictments in this ease, the Internal Revenue Service inquired into Ms. Christofalos’ failure to file federal personal income tax returns in 1981, 1982, and 1983. This investigation was discontinued in 1986. A Special Agent’s Report (SAR) reviewing the investigation and recommending that it be discontinued had been prepared by the IRS special agent working on the ease. On November 16, 1987, two days before trial, the district court granted Ms. Christofalos’ motion for exculpatory material under Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963), and ordered the government to produce any portion of the SAR pertaining to Ms. Christofalos. The government made the report available to Ms. Christofalos’ counsel the next day. On the first day of trial, November 18, the district court granted the government’s motion in limine prohibiting Ms. Christofa-los from introducing evidence of the special agent’s recommendation that the investigation be discontinued. See Tr. at 93. The court, however, did not prohibit Ms. Chris-tofalos from informing the jury of the fact that the investigation was discontinued or from introducing any factual material arising out of the discontinued IRS investigation. Only the agent’s reasons for recommending discontinuation of the investigation were to be excluded. See Tr. at 93-94. Ms. Christofalos contends that the court’s evidentiary ruling denied her the fundamental constitutional right to present a defense and constitutes reversible error. We disagree. It is a well-established principle that district courts have broad discretion to assess the relevance of proffered evidence. See United States v. Fuesting, 845 F.2d 664, 673 (7th Cir.1988); United States v. West, 670 F.2d 675, 682 (7th Cir.), cert. denied, 457 U.S. 1139, 102 S.Ct. 2972, 73 L.Ed.2d 1359 (1982). Therefore, we shall only reverse a district court’s evidentiary ruling where there has been a clear abuse of that wide discretion. No abuse of discretion has been demonstrated in this case. The district court concluded that the agent’s recommendation was not relevant because the prosecutor, not the agent conducting the investigation, was responsible for making the final decision to terminate the investigation. See Tr. at 91-92. Criteria other than the merits of the investigation itself may have gone into the prosecutorial decision to terminate the investigation. See Tr. at 93. Moreover, the earlier IRS investigation involved Ms. Christofalos’ failure to file personal income tax returns, a wholly different charge than the charge before the district court—conspiracy to impede the IRS through fraudulent business transactions. See Tr. at 92. In addition, the district court reasonably believed that admitting the special agent’s recommendation would have led to considerable confusion. If that recommendation were admitted, the court would then be required to consider allowing the government to call other IRS agents to rebut that recommendation. Under these circumstances, the district court’s decision to exclude evidence of the special agent’s recommendation to discontinue the earlier IRS investigation was not an abuse of discretion. C. Issues Raised by John Paul Doerr 1. Submission of tape transcripts to the jury At trial, the government presented audio tapes of conversations between an FBI undercover agent and several of the defendants. The jury was provided with transcripts of the tapes at the time the tapes were presented, and both the tapes and the transcripts were provided to the jury during its deliberations. Mr. Doerr asserts that there is an inaccuracy in one of the transcripts—the transcript incorrectly shows that he identified himself to the agent as “John Miller.” Because of this alleged inaccuracy in one of the transcripts, Mr. Doerr contends that the court erred in submitting the transcripts to the jury. We disagree. Trial courts possesses wide discretion in determining whether to allow juries to use written transcripts as aids in listening to audio tape recordings. See United States v. Keck, 773 F.2d 759, 766 (7th Cir.1985). In addition, we have previously held that allowing the jury to have the transcripts during their deliberations, as well as when the tapes are played during the trial, is not error. See United States v. Puerta Restrepo, 814 F.2d 1236, 1242 (7th Cir.1987); United States v. Dorn, 561 F.2d 1252, 1257 (7th Cir.1977). We cannot say that the district court abused its discretion in permitting the jury here to have the transcripts, as well as the tapes, during its deliberations. The court reasonably concluded that the transcripts would be helpful to the jury in this lengthy trial. See Tr. at 3898, 3916 (transcripts “would materially assist the jury here rather than making them listen to fairly long tapes”). In this case, as in Dorn, the “discrepancy] complained of [is] so minimal that [it] could not have substantially affected the meaning of the conversations.” 561 F.2d at 1257. In addition, Mr. Doerr’s challenge to the accuracy of the transcript was placed before the jury during defense counsel’s cross-examination of the agent who had prepared the tapes. See Tr. at 383-89, 415-16. Finally, the district court twice instructed the jury, once before the tapes were played and again prior to their deliberations, that the tapes, not the transcripts, were evidence in this case. The jury was clearly informed that, if there was any variation between the tapes and the transcripts, they were to rely solely on the tapes. See Tr. at 305, 4153; see also Puerta Restrepo, 814 F.2d at 1241; Dorn, 561 F.2d at 1257 (any problems arising from alleged inaccuracies in transcripts “were obviated by the meticulous instructions given the jury concerning the proper function of the transcripts”). Under these circumstances, the district court did not abuse its discretion in allowing the jury to have the transcripts during its deliberations. 2. Failure to prove existence and duration of conspiracy before trial Prior to trial, Mr. Doerr requested that the court hold a hearing, pursuant to Unit ed States v. Santiago, 582 F.2d 1128 (7th Cir.1978), to determine the admissibility of coconspirator's statements that he feared the government intended to introduce under Rule 801(d)(2)(E) of the Federal Rules of Evidence. In the alternative, he requested that the court order the government to submit a written proffer of proof substantiating the existence of the conspiracy alleged in Count One of the indictment. Mr. Doerr maintains that the evidence reflects that he withdrew from the conspiracy to engage in prostitution-related activities alleged in Count One when he moved from Kenosha to California in March 1982. In his pretrial motion (and in his brief on appeal), Mr. Doerr contended that he would be unfairly prejudiced by the introduction of coconspirator statements made after his withdrawal from the conspiracy. The district court, however, rejected Mr. Doerr’s request f