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Opinion PER CURIAM. PER CURIAM: The defendants, a corporation and its officers, challenge their convictions and sentences on various counts of fraud against the United States and its agencies. For the reasons set out below, we affirm their convictions in to to but remand for resentencing pursuant to Part X(F) of this opinion. I. Facts On appeal from a criminal conviction, this court must view the evidence in the light most favorable to the government, allowing it the benefit of all reasonable inferences that may be drawn from the evidence and permitting the jury to determine the weight and credibility of the evidence. United States v. Smith, 964 F.2d 1221, 1223 (D.C.Cir.1992); United States v. Butler, 924 F.2d 1124, 1126 (D.C.Cir.), cert. denied, — U.S. -, 112 S.Ct. 205, 116 L.Ed.2d 164 (1991). So viewed, the evidence reveals the following material facts. Defendant Automated Data Management, Inc. (ADM) is a Washington, D.C. firm founded in the early 1980s by defendant Michelle Ashton, its president. In late 1984, Ashton hired defendant David Dale as “Executive Vice-President” and at about the same time issued to him 18% of ADM’s stock, retaining the other 82% for herself. In early 1985, ADM obtained a contract to sell computers to the United States Army under the “minority set-aside” program of the Small Business Administration (SBA). In late 1985, ADM established offices abroad in Germany and Korea and hired a new vice-president to manage each: defendant Terence Sweeney in Germany and defendant David Bowers in Korea. In addition, defendant Martin Segal was hired as ADM’s in-house accountant in September 1986 and later received the title “Chief Financial Officer.” In August 1987 Bowers left ADM after a falling-out with Dale and Ashton — and after secretly taping telephone conversations he had with each of them. Bowers subsequently assisted a government investigation of ADM’s operations that led to the defendants’ indictments and convictions. Those convictions were based on the defendants’ allegedly fraudulent tax treatment of various financial transactions involving ADM’s Asian and European operations and on certain alleged misrepresentations or nondisclosures on government forms completed by defendants Ashton and Dale. We now summarize the facts underlying the convictions. A. Tax Fraud All five defendants were convicted both of tax fraud and of conspiracy to commit tax fraud. While the substantive tax fraud counts involved only ADM’s 1986 corporate return, the conspiracy count involved other aspects of ADM’s operations in both Asia and Europe. We describe separately the fraudulent activity relating to each location. 1. Asia After taking charge of ADM’s Korean operations, defendant Bowers determined ADM should take advantage of Asian business opportunities unrelated to its Army contracts. In order to circumvent legal restrictions on such activity, Bowers, after consulting with Dale, arranged for Nancy Edwards, a legal adviser to ADM’s Korean office, to set up a Guam corporation which would not be subject to the restrictions. Edwards and her husband incorporated Asia Management Systems, Inc. in late summer 1986. Soon thereafter the corporate name was changed to ADM Asia and ownership transferred to Ashton, Dale and Bowers. Ashton and Dale each acquired a 37.5% interest in the company, while Bowers received the remaining 25%. Upon Dale’s instruction to acquire additional companies, Bowers arranged for Edwards to purchase four Hong Kong corporations, Capulus, Fossano, Swaffham and Gemona, which were apparently shells with no assets other than documents of incorporation. During late October and early November 1986 ownership of Swaffham and Gemona was transferred to Ashton, Dale and Bowers in the same percentages as ADM Asia. There followed a number of financial transactions involving the related corporations on which the government based some of its tax fraud charges. First, during 1986 Bowers arranged for Dale and Ashton to obtain payments total-ling $50,000 from ADM funds channelled through the Korean office. Dale received $20,000 in February 1986 and Ashton received $20,000 in May and $10,000 in September. Neither Dale nor Ashton reported these amounts as personal income on their 1986 federal income tax returns. Second, between August 1986 and March 1987 ADM made three payments to related companies that it treated, falsely, as legitimate business deductions. In August 1986, ADM paid $200,000 to Arlington Associates (Arlington), a company owned in equal shares by Dale and Ashton. This payment was recorded in Arlington’s books as a bank loan from Guam National Bank. Sometime in late summer or early fall 1986, Dale instructed Bowers to draft documents representing that the $200,000 payment was a loan to Arlington from Asia Management Systems, Inc., the Guam corporation that Ashton, Dale and Bowers had acquired on August 29, 1986, and subsequently renamed ADM Asia, Inc. During December 1986 ADM paid a total of $417,532 to Swaffham and Gemona, the two Hong Kong companies acquired by Ashton, Dale and Bowers, for studies and services never actually performed. ADM recorded these payments as deductible business expenses. Finally, in March 1987 Bowers and Dale created a phony debt of $500,000 to Swaff-ham and documentation to support it. The debt was for software development purportedly performed by Swaffham but actually performed by employees of ADM in Korea at a cost of only about $30,000. The debt was treated as an accrual and deducted as a business expense on ADM’s 1986 tax return. 2. Europe In Germany, defendant Sweeney hired Larry Knight in February 1986 as a consultant to assist with the European operations. Later that same year, Sweeney and Knight formed an interim German partnership to enable ADM to take advantage of non-Army business opportunities in Germany until a German corporation could be established. On November 18, 1986, a German corporation, ADM Hard- und Software Handelgesellschaft GmbH in Deutschland (ADM H & S), was incorporated to assume the partnership’s business. Ownership of ADM H & S was divided among Ashton (87.5%), Dale (37.5%) and Sweeney (25%) and Knight was appointed general manager. Over the next two years, ADM made substantial payments to Bourbonia Invest AG, a Swiss investment firm operated by Gerd Wormer, an investment counselor and old friend of Knight. At trial, the government asserted and furnished evidence to show that these payments in fact accrued to the benefit of Ashton, Dale, ADM and ADM H & S and were fraudulently treated by ADM as business deductions. The first Bourbonia payment, for $316,-000, was made in December 1986, pursuant to two invoices signed by Wormer and dated December 11, 1986, a time when Sweeney and Knight were in the midst of a two-day meeting with Wormer at Wormer’s home. One of the invoices sought payment for “Product Development Consulting for the period March 86, to December 86,” Joint Appendix (JA) 1984, and the other “for Services rendered in accordance with letter contract as of March 11, 1986 for Machine Language Translation Research and Development Project,” JA 1985. Request forms to ADM for checks to pay the Bourbonia invoices were marked “OK MS from D. Dale 12/22/86” and “Sent Via Bank Wire 12/22/86” and one of them was signed by Segal. ADM deducted the $316,-000 payment as a business expense on its 1986 tax return. In late 1986, Bourbonia made a payment to ADM H & S of about $125,000 to purchase five vehicles, one for Knight’s use and the other four to be leased to ADM., Inc. Sweeney and Knight characterized the payment as a loan, but the government maintains the funds came from the $316,000 Bourbonia payment and were never intended to be repaid, which in fact they were not. The second Bourbonia payment was made in January 1988 pursuant to an invoice dated December 26, 1987, requesting payment of $102,655 for “consulting services for 1987 as per sep. agreement.” Ash-ton signed a check request form dated January 5, 1988, indicating payment had been requested by Segal and authorizing payment of the requested amount. Dale signed a check to Bourbonia for $102,655 dated January 26, 1988. Ashton and Dale both maintained investment accounts with Bourbonia at least as early as 1987. Forms filed with the IRS indicated that in 1987 each had $10,000-$50,000 in an account with Wormer, while in 1988 the balance in each account had grown to more than $100,000. B. Other Fraudulent Activity Apart from tax fraud, the jury also convicted Dale, Ashton and ADM of fraud in connection with four forms Dale and Ash-ton submitted to government agencies. The first three frauds involved forms Dale and Ashton filed with the Department of Defense (DOD) in early 1987 to obtain a security clearance for ADM. In late January and early February 1987, Dale and Ashton each completed a DOD “Personnel Security Questionnaire,” on which each responded “yes” to the question “Do you have any foreign property or business connections or have you ever been employed by or acted as a consultant or representative for a foreign government” and each identified the 87.5% interest held in ADM H & S and ADM Asia. Neither mentioned any connection with Gemona or Swaffham, although each had acquired a 37.5% interest in the two companies by November 1986. In early February 1987 each also completed a DOD “Statement of Full Disclosure of All Foreign Connections,” purporting to “hereby explain and fully disclose my foreign connections” but listing only their interests in ADM H & S. Finally, about the same time, Ashton signed a DOD “Certificate Pertaining to Foreign Interests” in which she responded “no” to the question “Does your organization have interlocking directors with foreign interests.” Dale also signed the document to certify that Ashton had authority to act on ADM’s behalf. The fourth fraud related to an “Application for Small Business Determination” Ashton filed with the Small Business Administration (SBA) on April 10, 1987. On the form she identified herself and Dale as officers of ADM and answered “yes” to the question “Are any of the persons listed [above as owners, partners, officers, directors, & principal stockholders] owners, partners, directors, officers, employees or principal stockholders in any other company?” In response to a direction to identify the other companies and offices held, however, she failed to mention her or Dale’s interests in or positions with Arlington, Swaffham, Gemona, ADM, ADM H & S or ADM Asia. C. Bowers’ Disaffection and Its Aftermath According to Bowers, in early 1987 he became concerned about his future with ADM and about potential criminal liability. As a result, he took a number of measures in contemplation of departing ADM. . First, in March 1987, he began to tape record telephone conversations he had with both Ashton and Dale, in an apparent effort to protect himself. Next, in April1987 Bowers withdrew about $100,000 from Gemo-na’s and Swaffham’s bank accounts, reasoning that the funds represented his 25% interest in the two corporations. Later, sometime after mid-July, he withdrew the remaining money from the corporations’ accounts, again, according to his testimony, to protect himself. Finally, on August 14, 1987, Bowers faxed a resignation letter to Ashton in the United States. In response to Bowers’ resignation, Ash-ton and Segal flew to Korea and negotiations ensued during which Ashton, through Segal, attempted to persuade Bowers to turn over all business records, including all tape recordings of telephone conversations, to surrender his interests in ADM Asia, Gemona and Swaffham and to agree to several measures designed to protect the interests of ADM, Dale and Ashton. Ultimately, Bowers returned to the United States, without succumbing to Ashton’s demands, and sought legal counsel. After Bowers’ resignation ADM and its principals took steps to alter the tax treatment of many of the transactions described above. First, sometime in August or September 1987, Segal informed ADM’s outside accountant, Grant Thornton, that ADM’s records had to be changed because of recently discovered information, namely that the $417,532 paid to Gemona and Swaffham in December 1986, allegedly for marketing studies, was not deductible and that there were additional Korean revenue of $348,-337 that had not previously been “booked.” The accountants accordingly prepared ADM’s 1986 tax return, which, pursuant to an extension, was not filed until September 15. 1987, to reflect this information. An amended return, filed in 1988, reduced the amount of the additional revenue to $311,-643. Second, on November 30, 1987, Dale and Ashton met with their personal accountant and told him they had received expense advances in 1986 that had not been included on their 1986 individual returns. After this meeting, Ashton filed an amended 1986 tax return dated December 2, 1987, adding to her taxable income $40,000 that she characterized as “travel advances not included in her 1986 W-2 wages.” JA 2217-18. Dale decided against filing an amended return because he wanted to determine whether his extra $10,000 might be offset by amounts ADM owed him. He subsequently added the $10,000 to the taxable income reported in his 1987 tax return. Third, at some point, probably after August 21, 1987, Dale and Ashton signed a promissory note to repay ADM the $200,-000 it had furnished to Arlington in August 1986. The payment to Arlington had initially been recorded as a loan from Guam National Bank and was later characterized by Dale as a loan from Asia Management Systems, Inc. This note is now marked “paid 12/31/87.” JA 1979. Fourth, at some point, apparently during summer 1988 after federal agents searched ADM’s headquarters on June 16, 1988, Se-gal informed one of ADM’s accountants that in December 1986 ADM had mistakenly paid $316,000 in consulting fees on behalf of ADM H & S and asked what should be done. The accountant then prepared an amended 1986 return, dated August 25, 1988, and signed by Ashton, eliminating the deduction previously taken for the December 1986 Bourbonia payment. In a memorandum to the accountant dated August 8, 1988, Segal explained that both that payment and the $102,655 payment in the following year “were paid in error by ADM, Inc.” JA 2349. The memo further stated that “a loan will be set up in Michelle’s and David’s name to ADM, Inc. for the amounts sent to Bourbonia” and that “[¡Interest on the notes will accrue from the day the funds were disbursed from ADM, Inc.” Id. Subsequently, four promissory notes were prepared, dated August 10, 1988, dividing the indebtedness between Dale and Ashton according to their respective ownership interests in ADM. Ashton and Dale each signed two of the notes and Segal witnessed all four. Each note is now marked “Paid 8/12/88.” See JA 2034, 2035. Finally, in March 1989, after additional government investigation and subpoenaing of documents, Segal told one of ADM’s accountants that he had discovered a $500,-000 accrual taken as a deduction in 1986 that had not been reversed when it later went unpaid. Accordingly, the accountant prepared an amended return, dated March 30, 1989, deleting the $500,000 deduction, and Segal signed it. The amended return explained its purpose as “[t]o adjust consulting expense for amounts accrued in 1986 but never paid subsequent December 31, 1986 [sic] and erroneously not reversed by Accounting Department.” JA 2253. D. Indictment and Trial On January 11, 1990, an indictment was returned against ADM, Dale, Ashton, Sweeney and Segal, charging the following counts: (1) Against all five defendants: conspiracy (in violation of 18 U.S.C. § 371) (a) to defraud the United States by impeding the IRS’ assessment and collection of taxes and (b) to commit the following offenses against the United States: (i) tax evasion (26 U.S.C. § 7201), (ii) subscribing to a false return and aiding and abetting the preparation of a false return (26 U.S.C. §§ 7206(1) and 7206(2)) and (iii) false statements and concealing facts by trick, scheme and device from the IRS, the SBA and the DOD (18 U.S.C. § 1001); (2) Against Dale and ADM: subscribing to a false tax return (in violation of 26 U.S.C. § 7206(1)) (for signing the 1986 ADM tax return falsely deducting the $500,0000 debt to Swaffham and the $316,000 payment to Bourbonia); (3) Against Ashton, Sweeney and Se-gal: aiding and assisting in the preparation and presentation of a false and fraudulent return (in violation of 26 U.S.C. § 7206(2)) (for actions related to ADM’s 1986 return and its two fraudulent deductions); (4) Against all five defendants: attempted tax evasion (in violation of 26 U.S.C. § 7201) and aiding and abetting (in violation of 18 U.S.C. § 2) (for actions related to the underreporting of taxable income on ADM’s 1986 return); (5) Against Dale, Ashton, Sweeney and ADM: wire fraud (in violation of 18 U.S.C. § 1343) and aiding and abetting (in violation of 18 U.S.C. § 2) (for causing the wire transfer of the $316,000 Bourbo-nia payment with intent to commit tax fraud); (6) Against Ashton and ADM: concealing facts by trick, scheme and artifice (in violation of 18 U.S.C. § 1001) and aiding and abetting (in violation of 18 U.S.C. § 2) (for Ashton’s nondisclosure of her relationship with Gemona or Swaffham in the DOD “Personnel Security Questionnaire”); (7) Against Dale and ADM: concealing facts by trick, scheme and artifice (in violation of 18 U.S.C. § 1001) and aiding and abetting (in violation of 18 U.S.C. § 2) (for the same nondisclosure in Dale’s “Personnel Security Questionnaire”); (8) Against Ashton and ADM: concealing facts by trick, scheme and artifice (in violation of 18 U.S.C. § 1001) and aiding and abetting (in violation of 18 U.S.C. § 2) (for Ashton’s nondisclosure of her Swaffham and Gemona interests in her February 1987 “Statement of Full Disclosure of All Foreign Connections”); (9) Against Dale and ADM: concealing facts by trick, scheme and artifice (in violation of 18 U.S.C. § 1001) and aiding and abetting (in violation of 18 U.S.C. § 2) (for Dale’s identical nondisclosure); and (10) Against Dale, Ashton and ADM: making false statements (in violation of 18 U.S.C. § 1001) and aiding and abetting (in violation of 18 U.S.C. § 2) (for denying the existence of interlocking directorships with foreign interests in the “Certificate Pertaining to Foreign Interests”). JA 141-74. On July 23, 1990, after a lengthy trial, a jury returned a guilty verdict on each count against each defendant named therein. On July 15, 1991, the trial court sentenced Dale, Ashton, Segal and ADM. Dale was sentenced to 41 months’ imprisonment on count 1, with concurrent 30 month sentences on each of the other counts against him, 2 years’ supervised release, a special assessment of $350 and a $675,000 fine and was assessed $58,037.96 for incarceration costs. Ashton was sentenced to 37 months’ imprisonment on count 1, with concurrent 30 month sentences on each of the other counts against her, 2 years’ supervised release and a $225,000 fine and was assessed $52,375.72 for incarceration costs. Segal was sentenced to 24 months’ imprisonment on count 1, with concurrent sentences of 12 months on each of the other counts against him. ' ADM was assessed a $360,000 fine and a $450 special assessment. Sweeney’s sentencing was delayed until August 13, 1991, when he was sentenced to concurrent prison terms of 18 months on counts 1, 3, 4 and 5, 2 years of supervised release and a $15,000 fine. The defendants challenge both their convictions and sentences and we address their various arguments below. II. Sufficiency of the Evidence Each defendant challenges the sufficiency of the evidence to support the convictions. The court’s review here is a narrow one. First, as noted above, we must view the evidence in the light most favorable to the government, deferring to the jury’s weight and credibility determinations. United States v. Smith, 964 F.2d 1221, 1222 (D.C.Cir.1992); United States v. Butler, 924 F.2d 1124, 1126 (D.C.Cir.), cert. denied, — U.S. -, 112 S.Ct. 205, 116 L.Ed.2d 164 (1991). In addition, the court must affirm each conviction if any rational trier of fact could have found the essential elements of the offense charged beyond a reasonable doubt. United States v. Long, 905 F.2d 1572, 1576 (D.C.Cir.), cert. denied, 498 U.S. 948, 111 S.Ct. 365, 112 L.Ed.2d 328 (1990). Applying these principles, we reject seriatim each defendant’s sufficiency challenge. A. Ashton Defendant Ashton contends there was insufficient evidence to support her conviction on any of the counts on which she was convicted, namely counts 1, 3, 4, 5, 6, 8 and 10. For the following reasons, we find the evidence sufficient to support her convictions on all seven counts. First, Ashton argues we must reverse her convictions on counts 6, 8 and 10, charging her with concealing facts from and making false statements to the federal government in violation of 18 U.S.C. § 1001 and those portions of count 1 alleging conspiracy to violate that section because the evidence was insufficient to establish either that her misstatements or nondisclosures on the DOD and SBA forms were made “knowingly and willfully,” as required under the statute, or that they were material. We find neither contention persuasive. Ashton’s first challenge to her convictions on counts 6, 8 and 10 is that under a reasonable interpretation of the forms cited in those counts, her statements on them were literally true and complete. While Ashton’s interpretation of the law regarding section 1001 appears consistent with the holdings in other circuits, we nevertheless conclude her convictions must be affirmed because, her statements on those forms were not literally true under a reasonable interpretation of the forms. Ashton first claims she could not be convicted under counts 6 and 8 because the expressions “foreign ... business connections” in the “Personnel Security Questionnaire” (count 6) and “foreign connections” in the “Statement of Full Disclosure of All Foreign Connections” (count 8) can reasonably be interpreted to refer only to “actual status as an owner or director of a foreign company,” and that she did not enjoy that status when she completed those forms because certain formalities required under Hong Kong law had not yet been satisfied. We reject this claim summarily, finding Ashton’s interpretation of “connections” far too restrictive. In its common usage, the word “connection” has a broad meaning that certainly embraces Ash-ton’s relationship to the two Hong Kong corporations of which she was by January 1987 indisputably both an owner and director, if not de jure at least de facto. Because Ashton’s proffered construction of the forms’ language was unreasonable, we reject her challenge to her convictions on counts 6 and 8. We similarly reject Ashton’s challenge to count 10. Ashton contends her denial on the 1987 “Certificate Pertaining to Foreign Interests” that ADM had “interlocking directors with foreign interests” was literally true because foreign interests can reasonably be construed to exclude foreign corporations owned by American citizens. We disagree. A “foreign corporation” is clearly a “foreign interest” regardless of ownership, as Ashton herself acknowledged when, on the “Statement of Full Disclosure of all Foreign Connections,” she identified herself as a “Representative of a Foreign Interest” based on her interest in ADM H & S. Ashton also asserts the count 10 conviction must be reversed because the misrepresentation alleged in that count, the denial of any “foreign interests” in the January 1987 “Certificate Pertaining to Foreign Interests,” was not material. Ash-ton reasons that, because the interlocking directorships between ADM and ADM H & S were discoverable from the February 1987 “Statement of Full Disclosure of All Foreign Connections,” in which she identified ADM H & S as a foreign interest in which she, Dale and Sweeney were directors, it could not have influenced or been material to the DOD. We find this argument also unavailing. Admittedly, in order to give rise to criminal liability under section 1001, a concealment or affirmative misrepresentation must be material. United States v. Hansen, 772 F.2d 940, 949 (D.C.Cir.1985), cert. denied, 475 U.S. 1045, 106 S.Ct. 1262, 89 L.Ed.2d 571 (1986). Nevertheless, even assuming that the earlier disclosure of ADM’s relationship with ADM H & S rendered nondisclosure of that relationship here immaterial, it does not affect Ashton’s liability for failing to disclose the interlocking directorships with Swaffham and Gemona which had not been otherwise disclosed to the DOD and therefore were material. Ashton’s final sufficiency challenge is that the trial evidence failed to establish that she “willfully” participated in the fraudulent tax deductions alleged in counts 3 and 4, as required under 26 U.S.C. §§ 7206(2) and 7201, or that she had a “conscious knowing intent to defraud” in connection with the wire transfer of funds to Bourbonia alleged in count 5, as required under 18 U.S.C. § 1343, the wire fraud statute. All three of the challenged counts alleged fraud in connection with ADM’s claimed 1986 deductions of the $500,000 Swaffham accrual and the $316,-000 Bourbonia payment. Ashton argues there was no evidence that she was aware the Bourbonia payment was not deductible or that the Swaffham payment was ever made, much less that it was not deductible. We disagree, finding ample evidence to support a finding of the requisite intent. The evidence against Ashton here is similar in nature and weight to the evidence in United States v. Treadwell, 760 F.2d 327 (D.C.Cir.1985), cert. denied, 474 U.S. 1064, 106 S.Ct. 814, 88 L.Ed.2d 788 (1986), in which this court affirmed the conviction of Treadwell, a real estate firm’s chief executive officer, for conspiring with subordinates to violate federal law even though Treadwell exercised little control over day-to-day operations and claimed to have reimbursed the project and fired one of her subordinates after she learned of the misconduct. The Treadwell court upheld the conviction based on the following circumstantial evidence: (1) Treadwell’s close personal and business relationships with the malfeasant subordinates, (2) her regular meetings with them, (3) her extensive experience “as a government-grant entrepreneur” and (4) her attempt to conceal the misconduct by altering and destroying documents. Id. at 333-35. The court concluded: “Combining these factors with the sheer magnitude of the [illegal acts], many involving other businesses that she controlled, would fully support a reasonable inference that Treadwell knew of and condoned her subordinates’ malfeasance.” Id. at 335. Similar evidence here, when viewed most favorably to the government, supports Ashton’s conviction. The record yields the following facts to support the finding that Ashton willingly participated in the frauds alleged: (1) she was the majority shareholder in all of the corporations; (2) she took an active role in the corporations, signing authorizations and travelling to the foreign offices; (3) the frauds conferred a financial benefit on ADM, Swaffham and ADM H & S, in which she owned controlling interests, as well as on her personal Bourbonia investment account; (4) these transactions were part of a much larger scheme to defraud the government, which included Ashton’s personal withdrawals of ADM funds which she failed to report as income and misrepresentations to government agencies; (5) one of her other misrepresentations was the concealment of the existence of Swaffham, one of the corporations benefited by the frauds; and (6) she personally assisted in covering up many of the frauds, including the $316,-000 Bourbonia deduction. As in Tread-well, the combination of these facts suffices to support the jury’s finding that Ashton willfully and intentionally participated in the frauds alleged. B. Sweeney Sweeney challenges the sufficiency of the evidence to support his conviction on counts 1, 3, 4 and 5, advancing two arguments: (1) the evidence did not establish that the payments to Bourbonia, or their tax treatment, were fraudulent and (2) assuming there was fraud, the evidence did not support a finding of specific intent on his part to evade taxes. We find neither argument persuasive and conclude the evidence is sufficient to support Sweeney’s conviction on all four counts. Sweeney first asserts theré was insufficient evidence to establish that the invoices to Bourbonia were in fact fraudulent. We find, however, that the record contains substantial evidence that the invoices were issued for the express purpose of diverting tax-free funds for the benefit of Ashton, Dale and ADM H & S, while conferring a tax benefit on ADM, and that the services identified in them were never intended to be performed. First, although the December 1986 invoices purported to charge for “Product Development Consulting for the period March 86, to December 86” and “for Services rendered in accordance with the letter contract as of March 11, 1986 for Machine Language Translation Research and Development Project,” JA 1984-85, Knight, who had been a consultant to ADM since February 1986, who had frequently spoken by phone with Wormer during that time, who was the only employee of ADM H & S as of December 1986, and who was meeting with Sweeney and Wormer the entire day of December 11, 1986, the date on the invoices, nevertheless “had no knowledge” that as of December 1986 Wormer had performed $316,000 worth of work for ADM H & S or that ADM had entered any contract with Bourbonia. In addition, despite government subpoenas, no contract with Bour-bonia has ever been produced and Crystal Day, ADM’s “Director of Contracts,” testified that despite a thorough search she was unable to find such a contract and was in fact informed by Sweeney that none existed. Nor was Day able to discover any actual reports from either year, although the 1987 invoices expressly stated that “specific reports were produced or are now underway.” Trial Transcript (Tr.) 2573. In fact, Day herself testified she never heard of Bourbonia before December 1988, although she attended weekly meetings with Ashton, Dale and “mid-level management.” Further, despite Sweeney’s assertion in a February 19, 1988, memorandum that Bourbonia “provides invaluable services to me on virtually a day-to-day basis,” JA 1994, three witnesses who worked in ADM’s German office between 1986 and 1987, namely Lyddi Hudson, Yvonne Burr and Sally Frank, testified they were unaware of any consultation arrangement with Bourbonia, or any Swiss firm, even though Burr had been with the German office since its establishment and the other two women had attended weekly meetings with Sweeney and the other “key players.” Finally, after the federal investigation began, ADM took steps to reverse the initial tax treatment of the $316,000 and $102,655 Bourbonia payments as deductible expenses and Dale and Ashton assumed personal responsibility for repaying both amounts to ADM, signing promissory notes and, according to notations on those notes, paying them off. Sweeney next asserts that even if the invoices were fraudulent, there is no evidence that he personally knew the fraud was committed for the purpose of tax evasion. In support of his argument, Sweeney relies heavily on the Ninth Circuit’s opinion in United States v. Salerno, 902 F.2d 1429 (9th Cir.1990). We find the reasoning in Salerno inapplicable here. In Salerno the Ninth Circuit reversed the tax evasion conviction of a former casino manager and his assistant who had embezzled money from the casino through a scheme that made it appear that the missing money had been won by customers, thereby entitling the casino to deduct the stolen amounts on its tax returns. The Salerno court properly found the evidence insufficient because it failed to show the two defendants embezzled the money “not merely for their own benefit but with a specific intent to cause the casino to file false tax returns.” Id. at 1432. In so finding, the court explained: The government at trial identified no persons other than [the defendants], the cashier and the runner as being involved in the scheme. None of the four individuals was an officer, shareholder, or director of the taxpayer corporation. There was no evidence that any of those individuals had anything to do with the preparation of [the corporation’s] tax returns. There was no evidence linking the embezzlement scheme to any officer, director or shareholder of the taxpayer corporation. There was no evidence that the defendants had any motive for conducting a scheme to defraud the government, or that they ever mentioned their own taxes, much less the tax returns of the casino. Id. at 1432. In fact, the court concluded: “In this case the filing of the corporate return appears irrelevant to the defendant’s conduct.” Id. at 1433. Not so here. Sweeney was a corporate vice-president who, according to the evidence, may have been promised an equity position. Further, the fraud, as alleged, involved a conspiracy among Sweeney and both principals of the corporation and its only apparent purpose was to obtain unwarranted favorable tax treatment through untaxed disbursements to Ashton, Dale and ADM H & S and unjustified deductions for ADM. Sweeney was certainly in a position to be aware of such a motive and the jury could reasonably have so inferred. Accordingly, we find the evidence, taken as a whole, sufficient to support a finding of specific intent by Sweeney to evade tax liability on ADM’s behalf. C. Segal Finally, Segal challenges the sufficiency of the evidence to support his conviction on counts 1, 3 and 4 and, in addition, challenges the trial court’s denial of his motion for a new trial. We reject both challenges, addressing each separately. First, Segal contends his convictions should be reversed because the evidence was insufficient to establish beyond a reasonable doubt that he knowingly participated in any of the fraudulent activity, asserting he was merely an innocent employee performing the accounting responsibilities his job required. We conclude, however, that the evidence, viewed most favorably to the government, reveals the following facts sufficient to support a finding of knowing participation in the tax frauds: (1) Segal was ADM’s Chief Financial Officer and as such reported directly to Ashton and Dale and attended high-level company meetings with them around the world; (2) Segal failed to disclose to Grant Thornton, ADM’s outside accounting firm, that the suspect transactions with ADM Asia, Gem-ona, Swaffham and ADM H & S were related-party transactions — in fact, he signed a letter to Grant Thornton, dated May 27, 1987, stating, inter alia, that “[rjelated party transactions and related amounts receivable or payable, including sales, purchases, loans, transfers, leasing arrangements and guarantees” had been “properly recorded or disclosed in the financial statements,” JA 2298, while as of that date the $200,000 Arlington payment, the $417,532 payments to Swaffham and Gemona and the $500,000 Swaffham accrual had already occurred but not been identified as related-party transactions; (3) Se-gal knew or should have known that the amount of the $500,000 Swaffham invoice was artificial and that the invoice itself was not bona fide; (4) it was Segal whom Ashton selected to accompany her to Korea in August 1987 and to' negotiate with Bowers, even though it was likely, if not inevitable, that the negotiations would involve discussion of some of the fraudulent activities, as in fact they did; (5) after the Korean sojourn, Segal continued to conceal from Grant Thornton some of the fraudulent tax transactions of which he must have known by then; and (6) in 1988 Segal furnished ADM’s accountants a false explanation of why the 1986 tax return had to be amended to eliminate the deduction of the $316,000 Bourbonia payment. Accordingly, we reject Segal’s first sufficiency challenge. Next, Segal asserts that even if the evidence was sufficient to support his conviction, the district court nevertheless erred in denying his motion for a new trial on the grounds that the verdict was against the weight of the evidence and that newly discovered evidence, namely testimony given by Sweeney after trial but before sentencing, established Segal’s innocence. A motion for new trial on either of the grounds asserted is committed to the trial court’s sound discretion and may be reversed only for abuse of that discretion. See United States v. Rogers, 918 F.2d 207, 213 (D.C.Cir.1990); United States v. Sensi, 879 F.2d 888, 901 (D.C.Cir.1989). We conclude there was no abuse of discretion here. First, we find no error in the district court’s denial of the motion insofar as it was based on the weight of the evidence. In considering a new trial motion based on the weight of the evidence the district judge “weighs the evidence and evaluates the witnesses’ credibility and decides whether ‘a serious miscarriage of justice may have occurred.’ ” Rogers, 918 F.2d at 213 (quoting Tibbs v. Florida, 457 U.S. 31, 38 n. 11, 102 S.Ct. 2211, 2216 n. 11, 72 L.Ed.2d 652 (1982)). Our review of the district court’s decision is particularly narrow when the court denies the new trial motion because the court’s decision accords with the jury’s. Hutchinson v. Stuckey, 952 F.2d 1418, 1420 (D.C.Cir.1992) (citing McNeal v. Hi-Lo Powered Scaffolding, Inc., 836 F.2d 637, 646 (D.C.Cir.1988)). Given this limited scope of review and the evidence set out above supporting Segal’s knowing participation in the tax evasion scheme, the trial court’s rejection of Se-gal’s weight of the evidence argument cannot be characterized as an abuse of discretion and must therefore be upheld. See United States v. Kelly, 748 F.2d 691, 701 (D.C.Cir.1984) (holding that, as long as the weight of the evidence clearly weighs in favor of conviction, not against it, there is no abuse of discretion in denying a new trial motion). Nor do we find error in the judge’s refusal to grant a new trial based on Sweeney’s post-trial testimony. To obtain a new trial based on newly discovered evidence, a convicted defendant must offer evidence that “ ‘ha[s] been discovered since the trial.’ ” Sensi, 879 F.2d at 901 (quoting United States v. Mangieri, 694 F.2d 1270, 1284 (D.C.Cir.1982)). The unanimous view of circuits that have considered the question is that this requirement is not met simply by offering the post-trial testimony of a co-conspirator who refused to testify at trial. See United States v. Reyes-Alvarado, 963 F.2d 1184, 1188 (9th Cir.1992) (“ ‘[W]hen a defendant who has chosen not to testify comes forward to offer testimony exculpating a codefendant, the evidence is not “newly discovered.” ’ ”) (quoting United States v. Diggs, 649 F.2d 731, 740 (9th Cir.), cert. denied, 454 U.S. 970, 102 S.Ct. 516, 70 L.Ed.2d 387 (1981)); United States v. Gustafson, 728 F.2d 1078, 1084 (8th Cir.) (finding no abuse of discretion in denying new trial motion based on probability that post-trial testimony of convicted co-defendants, who had agreed to provide government with information in return for lenient sentence, would deviate from their trial testimony and no longer implicate defendant-appellant), cert. denied, 469 U.S. 979, 105 S.Ct. 380, 83 L.Ed.2d 315 (1984); United States v. Metz, 652 F.2d 478, 480 (5th Cir. Unit A Aug. 3, 1981) (rejecting contention that “ ‘newly available’ evidence is synonymous with ‘newly discovered’ evidence” and finding no abuse of discretion in denial of new trial motion based on co-defendant’s post-conviction exculpating affidavits); United States v. Jacobs, 475 F.2d 270, 286 n. 33 (2d Cir.) (“[W]e fully agree with the judge’s alternative ground [for denying a new trial motion], that a court must exercise great caution in considering evidence to be ‘newly discovered’ when it existed all along and was unavailable only because a co-defendant, since convicted, had availed himself of his privilege not to testify.”), cert. denied, 414 U.S. 821, 94 S.Ct. 131, 38 L.Ed.2d 53 (1973). We recently acknowledged this principle in the administrative context to hold that the National Transportation Safety Board had reasonably concluded the proffered testimony of an FAA inspector who had invoked his fifth amendment privilege at a pilot certification hearing but had since pleaded guilty to charges related to the hearing’s subject-matter did not constitute “newly discovered” evidence under an NTSB rule so as to warrant reconsideration of the certification denial. See Chirino v. NTSB, 849 F.2d 1525 (D.C.Cir.1988). In light of our holding in Chirino and the holdings of the other circuits in the cited cases, we conclude it was not an abuse of discretion to deny a new trial based on Sweeney’s post-trial testimony. III. Admission of Tapes A. Title III Title III of the Omnibus Crime Control and Safe Streets Act of 1968, 18 U.S.C. § 2510 et seq., provides, in relevant part, that a person may intercept wire, oral or electronic communications to which the person is a party “unless such communication is intercepted for the purpose of committing any criminal or tortious act in violation of the Constitution or laws of the United States or of any State.” 18 U.S.C. § 2511(2)(d). In their motion to suppress the tape recordings made by Bowers and Roth, the defendants argued that the taping violated Title III because the purpose for taping was to blackmail Dale and Ash-ton for stock and money. The government responded with three independent arguments: (1) Title III does not apply extrater-ritorially and therefore is inapplicable to Bowers' taping in Korea of phone calls to and from the United States; (2) even if Title III applies extraterritorially and Bowers and Roth made the tapes for an illegal purpose, Title III does not mandate suppression where the government is the innocent recipient of tapes made by unindicted co-conspirators in the course of criminal activity; and (3) the defendants failed to meet their burden of proving that Bowers’ or Roth’s primary purpose in taping was either criminal or tortious. The district court did not state explicitly why it denied the motion to suppress, explaining only that it had conducted a three-day evidentia-ry hearing and that “[a]fter careful consideration of the motion, the opposition thereto and the entire record in this case,” the motion should be denied. JA 917. The defendants did not object to the district court’s failure to state its essential findings of fact on the record. See Fed.R.Crim.P. 12(e). On appeal, the defendants and the government repeated the same arguments regarding suppression of the tapes that they made to the district court. Normally, where the district court denies a motion to suppress but fails to make findings of fact on the record, we may sustain the district court’s decision “if there is any reasonable view of the evidence that will support it.” Scarbeck v. United States, 317 F.2d 546, 562 (D.C.Cir.1962), cert. denied, 374 U.S. 856, 83 S.Ct. 1897, 10 L.Ed.2d 1077 (1963); see also United States v. Mitchell, 951 F.2d 1291, 1299 (D.C.Cir.1991), cert. denied, — U.S. -, 112 S.Ct. 1976, 118 L.Ed.2d 576 (1992); United States v. Caballero, 936 F.2d 1292, 1296 (D.C.Cir.1991), cert. denied, — U.S.-, 112 S.Ct. 943, 117 L.Ed.2d 113 (1992); United States v. Allen, 629 F.2d 51, 57 (D.C.Cir.1980). However, we declined to exercise this option here because we did not know which of three separate legal theories advanced by the government the district court had adopted and what facts, if any, it relied on to support its chosen theory. By order dated January 8, 1993, we remanded the record to the district court for a clarification of its reasons for admitting the tapes and any relevant factual findings made in support of its admissibility ruling. See United States v. Williams, 951 F.2d 1287, 1290-91 (D.C.Cir.1991) (remand to the district court is appropriate where neither the legal reasoning nor factual findings supporting the denial of a motion to suppress are apparent because it is not clear “[o]ne, that the district court asked the right legal questions in making its ruling; two, that it actually weighed the evidence bearing on the facts needed to answer them”). On January 21, 1993, the district court responded with an order explaining that a memorandum had been prepared subsequent to the court’s denial of the defendants’ motion to suppress the tapes, but while “[i]t was the Court’s understanding that the Memorandum had been filed; it now appears that the Memorandum was not filed. The Memorandum sets forth the reasons the Court ... denied the motion to suppress tapes_ [A] copy of the Memorandum has been signed and is attached as Court Exhibit A.” United States v. Dale, Crim. No. 90-0027, Memorandum Order at 1-2 (D.D.C. Jan. 21, 1993). In the memorandum, which was filed and made a part of the record, the district court expressly eschewed the first two legal theories pressed by the government, that Title III does not apply extraterritorially or that it does not apply to the government’s innocent receipt of recordings made by a co-conspirator, stating that “[f]or the purpose of this motion, the Court will assume without deciding that Title III applies to all of the tape recordings at issue.” United States v. Dale, Crim. No. 90-0027, Memorandum at 2 n. 1 (D.D.C. Jan. 21, 1993) (“Tapes Memorandum”). Instead, the court found that the evidence supported the government’s third theory and concluded that the “defendants have failed to establish that the motivation for the taping by either Bowers or Roth was criminal or tortious.” Id. at 3. The district court explained that although Bowers was a willing participant in the illegality in the beginning, there came a time when he became an unwilling participant because he felt that there was a possibility that all of the responsibility for these activities could be placed on him. Bowers stated that he began taping conversations with the defendants at about this time in order to make sure his interests were protected. Specifically, Bowers asserted that with the taping he wanted to make a record which detailed the participation of defendants Ashton and Dale in the criminal activities taking place in Asia and show[ed] that he was receiving directions [from them] as to those activities. It was important to him that it was clear on the recordings that he was not acting alone since he feared that defendants would seek to portray him in that light. Id. at 5-6. The district court credited this testimony and found that the defendants had not rebutted Bowers’ explanation for the taping. Id. Similarly, the district court found Roth’s explanation that he made the tapes to keep a record of his employment dispute with ADM and not for purposes of extortion to be “entirely credible.” Id. at 4. We permitted the parties to file supplemental briefs addressing these findings, and after reviewing those briefs and the district court’s memorandum, we conclude that the district court’s factual findings were not clearly erroneous. The burden was on the defendants to prove that Bowers and Roth made the tapes for criminal or tortious purposes, see Traficant v. Commissioner, 884 F.2d 258, 266 (6th Cir.1989); United States v. Phillips, 540 F.2d 319, 326 (8th Cir.), cert. denied, 429 U.S. 1000, 97 S.Ct. 530, 50 L.Ed.2d 611 (1976), and the evidence supports the district court’s conclusion that the defendants failed to meet their burden. In their supplemental brief, the defendants contend that because the district court failed to mention every bit of evidence allegedly probative of Bowers’ and Roth’s intent, the court necessarily overlooked or ignored this evidence. However, the district court was obligated to state only its essential findings on the record, see Fed. R.Crim.P. 12(e), and we do not find that the district court neglected to consider any dis-positive evidence in the record. Indeed, the district court noted that “the evidence presented by defendants to support their claim that Roth conspired with Bowers in a blackmail and extortion plan is scant and unpersuasive,” and further that it “was not persuaded by defendants’ efforts to rebut Bowers’ testimony.” Tapes Memorandum at 4, 6. In any event, simply because the factual record could reasonably lead a fact-finder to conclude that Bowers and Roth did have an illegal or tortious purpose in taping does not mean that the district court’s contrary, and at least equally permissible, view of the facts is clearly erroneous. See Anderson v. Bessemer City, 470 U.S. 564, 574, 105 S.Ct. 1504, 1511-12, 84 L.Ed.2d 518 (1985). Neither do we find that the district court erred in its legal analysis. Taping phone calls to make an accurate record of a conversation “in order to prevent future distortions by a participant” is not illegal, see United States v. Underhill, 813 F.2d 105, 110 (6th Cir.), cert. denied, 482 U.S. 906, 107 S.Ct. 2484, 96 L.Ed.2d 376 (1987), even when the recording is made in the hopes of producing evidence of an illegal conspiracy, see By-Prod. Corp. v. ArmenBerry Co., 668 F.2d 956, 959-60 (7th Cir.1982). A person may even tape confederates in the hope of obtaining evidence to reduce his own sentence. See United States v. Ruppel, 666 F.2d 261, 271 (5th Cir. Unit A), cert. denied, 458 U.S. 1107, 102 S.Ct. 3487, 73 L.Ed.2d 1369 (1982). Given the district court’s determination that Bowers' purpose for taping was to protect himself and Roth’s purpose was to establish a record of his employment dispute, it would appear that the district court correctly concluded that the tape recordings were not made in violation of Title III. The defendants argue, however, that the district court “may well have applied an erroneous legal standard” by concluding that Title III is not violated where the primary purpose for taping is legal, even though a second, unlawful factor also motivated the taper. Appellants’. Joint Supplemental Brief at 6-7. The defendants are correct that a violation of Title III is established when “it is shown either (1) that the primary motivation, or (2) that a determinative factor in the actor’s motivation for intercepting the conversation was to commit a criminal, tor-tious, or other injurious act.” See United States v. Vest, 639 F.Supp. 899, 904 (D.Mass.1986), aff'd, 813 F.2d 477 (1st Cir.1987), cert. denied, 488 U.S. 965, 109 S.Ct. 489, 102 L.Ed.2d 526 (1988). Although the district court at one point in the memorandum referred to Roth’s “primary” purpose for taping, Tapes Memorandum at 3, it is clear to us that the district court, which cited Vest, recognized that the defendants were obligated to demonstrate only that some determinative factor in the taping was impermissible. Unfortunately for the defendants, there is no indication that the district court found any of the purposes motivating Bowers and Roth to be illegal. Instead, the court quite clearly stated that “defendants have failed to sustain their burden of proving that Roth acted with an impermissible purpose,” and that “defendants’ argument that Bowers’ motivation behind his taping was illegal or tortious is unconvincing.” Id. at 5-6. In sum, the district court correctly applied the appropriate legal standard in refusing to suppress the tapes. B. Authentication The defendants next argue that the district court erred by failing to make an explicit threshold determination that the tapes were trustworthy, especially in light of a defense expert’s report concluding there was a possibility that some tapes had been altered or recorded over. The admission of recordings into evidence is committed to the sound discretion of the trial court, so long as the tapes are authentic, accurate and trustworthy. See United States v. Sandoval, 709 F.2d 1553, 1554 (D.C.Cir.1983); United States v. Slade, 627 F.2d 293, 301 (D.C.Cir.), cert. denied, 449 U.S. 1034, 101 S.Ct. 608, 66 L.Ed.2d 495 (1980); United States v. Haldeman, 559 F.2d 31, 107 (D.C.Cir.1976), cert. denied, 431 U.S. 933, 97 S.Ct. 2641, 53 L.Ed.2d 250 (1977). It was not an abuse of discretion for the district court to admit the tapes into evidence without expressly stating that the tapes were reliable because the record indicates that the court accepted the government’s proffer of trustworthiness and rejected the defendants’ concerns. We believe that in admitting the tapes into evidence, the district court implicitly found that “ ‘the possibilities of misidentification and adulteration [were] eliminated, not absolutely, but as a matter of reasonable probability.’ ” Haldeman, 559 F.2d at 107 (quoting Gass v. United States, 416 F.2d 767, 770 (D.C.Cir.1969)). To meet its burden of demonstrating the authenticity and accuracy of the tapes, see United States v. King, 587 F.2d 956, 961 (9th Cir.1978), the government first produced IRS Special Agent Kenneth Buck who testified and was cross-examined at length regarding the tapes and in particular, about how the government had inadvertently damaged one part of one tape. Next, Bowers described the mechanism by which he taped telephone conversations, explained the circumstances under which he handed tapes over to government agents and testified that the tapes were fair and accurate recordings of conversations to which he was a party. In addition, the court engaged in a lengthy colloquy with counsel on the accuracy and reliability of the tapes, and the findings of the defense expert regarding potential tampering with the tapes. Finally, the district court gave the defendants the option of having the FBI technician who produced noise-reduced versions of the tapes testify regarding whether the tapes might have been tampered with prior to receipt by the FBI, which offer the defendants declined. Only after all of the foregoing did the district court admit the tapes into evidence and allow them to be played to the jury. There is no single rigid standard for determining whether a tape recording may be admitted into evidence. See United States v. Lance, 853 F.2d 1177, 1181 (5th Cir.1988) (federal courts do not require “conclusive proof of authenticity” before admitting tapes); Haldeman, 559 F.2d at 107 (evidence of admissibility of tapes “need not conform to any particular model”). Tapes may be authenticated by testimony describing the process or system that created the tape, see United States v. Sivils, 960 F.2d 587, 597 (6th Cir.), cert. denied, — U.S. -, 113 S.Ct. 130, 121 L.Ed.2d 84 (1992); Haldeman, 559 F.2d at 107-09, or by testimony from parties to the conversation affirming that the tape contained an accurate record of what was said. See Lance, 853 F.2d at 1181-82; Sandoval, 709 F.2d at 1555. The district court’s decision to admit the tapes was obviously based on its conclusion that the testimony of both the originator of the tapes and of the IRS agent established the authenticity, accuracy and trustworthiness of the tapes notwithstanding the misgivings of the defendants’ expert. Given the extended discussion of the objections and the government’s evidence in court, we are satisfied that the district court committed no reversible error in failing to make the basis of its ruling explicit. IV. Admission of Evidence fkom Search On May 18, 1990, the district court denied, without elaboration, the defendants’ motion to suppress evidence seized in a search of ADM’s offices and warehouse. In responding to our January 8, 1993 request to set forth its reasons for denying the defendants’ motion to suppress the tapes made by Bowers and Roth, the district court has provided this court with a second memorandum, also mistakenly believed by the district court to have been filed in 1990, explaining in detail why the court refused to suppress evidence seized in the search of ADM’s offices. United States v. Dale, Crim. No. 90-0027, Memorandum Order (D.D.C. Jan. 21, 1993) (“Warehouse Memorandum”). In their supplemental briefs,. the parties have addressed the search and suppression issues in light of the district court’s memorandum. A. Franks Hearing The defendants argue that the trial court erred in refusing to hold an evidentiary hearing under Franks v. Delaware, 438 U.S. 154, 98 S.Ct. 2674, 57 L.Ed.2d 667 (1978), to investigate alleged defects in the affidavit of Defense Criminal Investigation Service Special Agent Heidi Shintani supporting the warrant to search ADM’s offices and warehouse in Washington, D.C. Although a search warrant is presumptively valid, if the defendant is able to make a substantial preliminary showing that a false statement knowingly and intentionally, or with reckless disregard for the truth, was included by the affiant in the warrant affidavit, and , if the allegedly false statement is necessary to the finding of probable cause, the Fourth Amendment requires that a hearing be held at the defendant’s request. Id. at 155-56, 98 S.Ct. at 2676; see United States v. Sobamowo, 892 F.2d 90, 94 (D.C.Cir.1989), cert. denied, 498 U.S. 825, 111 S.Ct. 78, 112 L.Ed.2d 51 (1990). The defendants contend that they made such a showing before the district court by proffering evidence that: allegations in the warrant that ADM illegally substituted products in executing contracts with the Army were false and the affiant Shintani acted with reckless disregard for the truth by failing to investigate the validity of the allegations; the affiant misrepresented the credibility of David Bowers by failing to disclose that Bowers was himself under investigation; and the affiant lied about information provided by former ADM employees. We conclude that the district court properly rejected each of these claims. First, the defendants produced affidavits from Army officials to establish that ADM had approval from the Army to substitute Magna hard drives for the Wang or Yipcon hard drives originally contracted for. According to the defendants, Agent Shintani’s sole reliance on affidavits from former ADM employees and her failure to contact any Army officials amounted to reckless disregard for the truth. But in general, the failure to investigate fully is not evidence of an affiant’s reckless disregard for the truth. See United States v. Miller, 753 F.2d 1475, 1478 (9th Cir.1985); United States v. Mastroianni, 749 F.2d 900, 909-10 (1st Cir.1984); United States v. Young Buffalo, 591 F.2d 506, 510 (9th Cir.), cert. denied, 441 U.S. 950, 99 S.Ct. 2178, 60 L.Ed.2d 1055 (1979). As the district court explained, probable cause “does not require an officer to exhaust every possible lead, interview all potential witnesses, and accumulate overwhelming corroborative evidence.” Warehouse Memorandum at 18. In fact, Agent Shintani’s failure to contact Army officials may have been entirely prudent given the possibility of a leak back to ADM. According to the affidavit, one informant “indicated that Dale and ADM President Ashton would certainly destroy any incriminating records if they were subpoenaed. She stated Dale would do anything to avoid detection.” JA 258. Rather than evincing a reckless disregard for the truth, the agent’s actions amounted to at most negligence which is insufficient to warrant a Franks hearing. See Franks, 438 U.S. at 171, 98 S.Ct. at 2684. The defendants next argue that the affiant misrepresented Bowers’ credibility in the affidavit by describing him as a “Confidential Informant” when Bowers was himself under investigation. However, an affiant’s failure to disclose the backgrounds and alleged biases of informants does not establish the affiant's reckless disregard for the truth. See United States v. Wold, 979 F.2d 632, 634 (8th Cir.1992) (failure to disclose that informant had been drug dealer, was cooperating with police in order to receive leniency and was being paid by