Full opinion text
ESCHBACH, Circuit Judge. Appellants were convicted of conducting an illegal gambling business, conspiracy to conduct such a business, and (except DiSal-vo) willful failure to file certain tax forms, and they now appeal. We affirm their convictions. I. The convictions we review today arose out of a lengthy and painstaking government investigation of organized sports gambling activities in Milwaukee, Wisconsin, from 1977 into 1980. The government collected its evidence through physical surveillance, electronic surveillance, warrant-authorized searches, and infiltration by two undercover FBI agents. From this evidence the government developed its theory that the three appellants, along with a number of others, conspired to run a succession of sports gambling businesses during the period. According to the theory, Frank Balistrieri was the owner of the businesses, Steve DiSalvo supervised them, and Dennis Librizzi participated in at least one of them — a basketball bookmaking operation in early 1980. Appellants, along with many others, were indicted on October 1, 1981. The case was assigned to Judge Robert W. Warren. Balistrieri promptly filed a motion for the disqualification of Judge Warren, the first of several motions in an ultimately successful effort to induce Judge Warren to re-cuse himself. The case was reassigned to Judge Terence T. Evans for trial, and trial commenced on August 29, 1983. On October 9, 1983, the jury rendered its verdicts. II. Frank Balistrieri (No. 84-2001) Frank Balistrieri was convicted of one count of conspiracy to direct an illegal gambling business, in violation of 18 U.S.C. § 371, two counts of conducting an illegal gambling business, in violation of 18 U.S.C. § 1955, and two counts of failure to file certain tax returns, in violation of 26 U.S.C. § 7203. He was acquitted on one count of conducting an illegal gambling business and four other tax counts. On May 29, 1984, he was sentenced to four years imprisonment and a fine of $4,000 on the conspiracy, four years imprisonment and a fine of $10,000 on one of the § 1955 counts, four years imprisonment and a fine of $4,000 on the other § 1955 count, and one year imprisonment and a fine of $1,000 on each of the two tax counts, with all the sentences of imprisonment to run concurrently. On appeal, Balistrieri assigns eight errors in the proceedings below. A. Recusal of Judge Warren 1. Background Balistrieri contends that he is entitled to a new trial because Judge Warren, who decided virtually all of the pretrial motions, should have recused himself at the outset. Balistrieri moved four times to disqualify Judge Warren on the ground that Warren, during the period from 1969 into 1971 while serving as the Attorney General of Wisconsin, had formed a firm belief that Balistri-eri was the head of the Milwaukee Mafia and had announced that belief and acted on it as Attorney General on numerous occasions. Judge Warren denied the first three of Balistrieri’s recusal motions, holding that the first and second were inadequate to satisfy the statutory standard for disqualification and that the third was untimely. Coupled with the filing of the fourth motion, a week before the start of trial, a Milwaukee attorney, Roland J. Steinle, Jr., issued a press release charging that Judge Warren was personally responsible for an alleged 1969 burglary of his law office and theft of a client file relating to his representation of Balistrieri. Steinle also announced that he intended to file a civil lawsuit against Judge Warren and another person based on that alleged incident. Judge Warren, while categorically denying all these allegations, nevertheless recused himself because he thought that a reasonable person might find an appearance of partiality. Balistrieri argues that the recusal came too late; because Judge Warren should have recused himself at the start, none of his rulings on pretrial motions was valid. We disagree. We do not question Judge Warren’s exercise of discretion in recusing himself in the face of Steinle’s public activities, but we hold that he was under no obligation to recuse himself earlier. 2. The Affidavits Balistrieri submitted his first motion for recusal on October 26, 1981, shortly after Judge Warren’s assignment to the case. The affidavit accompanying the motion set forth various statements and actions attributed to Judge Warren during the period from 1969 through early 1971, when he was Attorney General of Wisconsin. According to the affidavit, Warren believed that Frank Balistrieri was the head of the Mafia family in Wisconsin. Warren allegedly set into operation a systematic program, or “vendetta,” designed to ruin Bal-istrieri and to destroy businesses with which he or his relatives were associated. As a part of this program, Warren moved to dissolve certain Balistrieri-linked corporations for failure to file annual reports, saying that this “crackdown” was an effort to keep the crime syndicate out of legitimate business in Wisconsin. Warren also sought injunctions against four Balistrieri-linked taverns for not having workmen’s compensation insurance. On November 28, 1969, fourteen agents (ten from the Attorney General’s office) participated in a raid on the Scene, a nightclub which the press described as linked to Balistrieri. In June 1970 Warren objected to the Milwaukee Common Council’s granting of liquor licenses to taverns associated with Balistri-eri. In an interview after almost two years in office, Warren said the following: A characteristic of organized crime ... is that it ignores many of the laws regulating businesses — laws which require annual reports, seller’s permits, workmen’s compensation insurance and restrict liquor credit. To get at organized crime in legitimate businesses, the State started a myriad of civil actions against businesses believed to be controlled by organized crime figures. “We had to start at the bottom with some rather mundane things,” Warren said. "For example, we found that the Balistrieri family had not been filing annual corporation reports.” The affidavit also set forth that ce.rtain individuals and corporations associated with Balistrieri filed two lawsuits against Warren, the first seeking injunctive relief and damages for the raid on the Scene, and the second seeking damages for the effort to close a certain nightclub for failure to have workmen’s compensation insurance. The first suit was voluntarily dismissed, and the second was dismissed on grounds of immunity. Balistrieri’s second motion for recusal was filed on July 20,1983. It incorporated the previous affidavit and included a new affidavit from one John Forbes. Forbes stated that he was then in the Federal Witness Protection Program, that he was then serving a sentence for burglary, and that over his life he had been charged with a number of crimes and convicted of several. He stated that in 1963 he became acquainted with one Herbert Krusche, a criminal investigator for the Wisconsin Department of Justice. According to Forbes, from 1968 through 1970, during the period when Robert Warren was Attorney General, Krusche asked Forbes to conduct a number of undercover investigations of Frank Balistrieri and persons alleged to be associated with him, in return for help in connection with criminal charges then pending. On several occasions in 1969 and 1970, Forbes related, he wore a body recorder or electronic listening device at Krusche’s request and monitored conversations of Frank Balistrieri and of his lawyer, Roland Steinle, among others. Krusche allegedly asked Forbes to break into someone’s apartment and plant a bug and to break into the basement of the Kings IV restaurant and plant a bottle of stolen liquor. On one occasion Krusche allegedly asked him to break into Steinle’s office and bring back any files he could find on Frank Balistrieri. Forbes stated that he complied with this request and brought back one file. According to Forbes, he met Robert Warren only once, in a meeting with other high officials of the Wisconsin Department of Justice. Forbes stated that he had made a tape of a conversation with someone about fixing a case pending against Forbes, then went with a reporter to the Attorney General’s office and turned over the tape. According to Forbes, someone stated that they could not use the tape “because it might be considered illegal or an entrapment or something of the sort.” Forbes continued: I made a statement to the effect I did not understand why they were concerned about it, in light of the number of times that I wore a bug for Mr. Krushe [sic] and went in places for him. Someone, I think [the Head of the Criminal Division], said “You better not talk about that.” [An assistant to Attorney General Warren] then asked if I had declared it on my Wisconsin tax return and kept a record of it. I said “no.” [The assistant] said “well, we did.” I understood this conversation to mean that I ought not to talk what [sic] I had done for Krushe [sic]. Attorney General Warren was present during this conversation. I do not remember any specific comments made by him. Except about entrapment etcetera, [sic] Balistrieri filed a third motion for recusal on August 16, 1983, attaching the affidavit of one Terrence Joseph Donley. According to Balistrieri, Donley contacted attorney John Balistrieri on August 11 after having read an article in the previous evening’s paper concerning Judge Warren’s denial of the previous motion for recusal. In the affidavit Donley stated that he worked for the Wisconsin Department of Justice from June through September 1970 as an “undercover operative.” According to Donley, his immediate supervisors included Robert Warren. In Donley’s presence Warren allegedly swore that he was going to get Frank Balistrieri no matter what. Warren was alleged to have said, in substance, “If it’s the last thing I do, I’m going to put Frank Balistrieri back in prison for the rest of his life.” According to Donley, Warren frequently made statements of his intention to get Frank Balistri-eri. Donley stated that a special detail of the Department of Justice under the supervision of Dan Hanley and under instructions from Warren was assigned to the Milwaukee detail on Frank Balistrieri and organized crime, and that it was the purpose of this detail to bring criminal charges against Frank Balistrieri. According to Donley, Warren would get upset if nothing was found. Donley stated that Frank Bal-istrieri and organized crime were among the top priorities on the Attorney General’s budget. Balistrieri filed his final motion for disqualification on August 22,1983. It included all the previous motions and supporting documents as well as new affidavits of Frank P. Balistrieri, John J. Balistrieri, and John C. Tucker, Frank Balistrieri’s attorney. In his affidavit Frank Balistrieri stated his belief that Judge Warren had personal bias and prejudice against him. He reiterated the factual allegations of previous affidavits. The only new factual material we find is a paragraph stating that Balistri-eri did not previously know Terrence Don-ley and did not give him anything for his affidavit, and a paragraph stating on information and belief that Judge Warren had said at a recent social gathering that he was delighted to be sitting in judgment in the case because he will have an opportunity to “put Frank Balistrieri away.” The affidavits of John J. Balistrieri and John C. Tucker concerned the circumstances under which Terrence Donley came forward and gave his affidavit. John Balistri-eri stated that he had never met Donley before and gave Donley nothing of value for his affidavit. They both stated, in substance, that news reports found in the Milwaukee Public Library confirmed certain statements that Donley had made regarding his background and his position as an informant for the State of Wisconsin during 1970. 3. Section 144 Section 144 of the Judicial Code, 28 U.S.C. § 144, requires a judge to recuse himself if a party files a timely and sufficient affidavit that the judge has “a personal bias or prejudice” against him. The law is clear that in passing on the legal sufficiency of the affidavit, the judge must assume that the factual averments it contains are true, even if he knows them to be false. E.g., United States v. Jeffers, 532 F.2d 1101, 1112 (7th Cir.1976), aff'd in part and vacated in part, 432 U.S. 137, 97 S.Ct. 2207, 53 L.Ed.2d 168 (1977). An affidavit is sufficient if it avers facts that, if true, would convince a reasonable person that bias exists. United States v. Bashes, 687 F.2d 165, 170 (7th Cir.1981) (per curiam). The factual averments must give fair support to the charge of a bent of mind that may prevent or impede impartiality of judgment. Berger v. United States, 255 U.S. 22, 33-34, 41 S.Ct. 230, 233, 65 L.Ed. 481 (1921). They must not, however, be mere conclusions, opinions, or rumors. United States v. Haldeman, 559 F.2d 31, 134 (D.C. Cir.1976), cert. denied, 431 U.S. 933, 97 S.Ct. 2641, 53 L.Ed.2d 250 (1977). They must be stated with particularity, id. at 131, and must be definite as to times, places, persons, and circumstances. Id. at 134. The factual averments must show that the bias is personal rather than judicial, United States v. Patrick, 542 F.2d 381, 390 (7th Cir.1976), cert. denied, 430 U.S. 931, 97 S.Ct. 1551, 51 L.Ed.2d 775 (1977), and that it stems from an extrajudicial source — some source other than what the judge has learned through participation in the case. United States v. Grinnell Corp., 384 U.S. 563, 583, 86 S.Ct. 1698, 1710, 16 L.Ed.2d 778 (1966). In view of the requirement that the judge assume that the facts are as stated in the affidavit, the statute, while not quite conferring a right of peremptory challenge, is heavily weighed in favor of recusal. Doubtless recognizing that so powerful an instrument could easily be abused, Congress imposed certain strict limitations and conditions to minimize that possibility. The affidavit must be timely, and a party may file only one in a case. It must be accompanied by counsel’s certificate that it is made in good faith. 28 U.S.C. § 144. Courts have recognized that the statute is to be strictly construed, e.g., Rademacher v. City of Phoenix, 442 F.Supp. 27, 29 (D.Ariz.1977), and that a judge is presumed to be impartial, Jeffers, 532 F.2d at 1112, so that a party seeking recusal bears a heavy burden. Bashes, 687 F.2d at 170. We have not found in our cases any discussion of the standard we apply in reviewing a judge’s decision not to recuse himself under § 144. As we read the statute, it was not the intent of Congress to make recusal under § 144 a discretionary determination. The statute states in positive terms that if a party files a timely and sufficient affidavit, the judge shall proceed no further. The judge is allowed to pass only on the timeliness and sufficiency of the affidavit, accepting the factual aver-ments as true. Whether the affidavit is timely and sufficient is a question of law, for which the appropriate standard of review is de novo. Because of the statutory limitation that a party may file only one affidavit in a case, we need consider only the affidavit filed with Balistrieri’s first motion. We must treat the factual averments as true, but not Balistrieri’s conclusions as to their significance. When Balistrieri says that Attorney General Warren conducted a “vendetta” designed to ruin him and destroy his businesses, he is drawing conclusions that we are not bound to accept. We take the affidavit to establish that from 1969 through early 1971, during his tenure as Attorney General of Wisconsin, Robert W. Warren believed that Frank Balistrieri was head of an organized crime family in Milwaukee and that he made the statements and took the actions against Balistrieri businesses that the affidavit sets forth, as part of an effort against organized crime. We also take it to establish that certain of Balistrieri’s relatives and business associates brought two lawsuits against Warren as a result of his actions. The affidavit clearly meets many of the requirements of the law set forth above. There is no doubt that it was timely. While it contains much that is conclusion-ary, it also contains relevant factual aver-ments, stated with particularity and definite as to times, places, persons, and circumstances. Since the events took place before Judge Warren became a judge, if the affidavit shows bias at all, it is personal rather than judicial, and it stems from an extrajudicial source. The only question, then, is whether the averments that we are bound to accept as true would convince a reasonable person that Judge Warren was biased against Balistrieri at the time the motion for disqualification was made. We hold that they would not. The most striking feature of the affidavit is that it is confined to events that took place ten to twelve years earlier. Even if the affidavit established that Attorney General Warren was biased against Balis-trieri during 1969 through 1971, it contains nothing to show that the bias persisted for over ten years, so as to infect the judgment of Judge Warren in 1981. This does not mean by itself that the affidavit is insufficient, for we know that certain biases tend to persist, but the absence of any current evidence of bias is a clear weakness. Furthermore, the events related in the affidavit bear no relationship to the charges in the indictment. The targets of the enforcement activities of 1969-71 were certain taverns and nightclubs selling alcoholic beverages at retail. The indictment arose out of alleged gambling businesses operating during 1977-80. Quite apart from the temporal gap, we do not think that the affidavit sufficiently avers facts that show that Attorney General Warren was biased or prejudiced against Balistrieri at the time of the actions related. When a law enforcement professional, be he Attorney General, a prosecutor, or a policeman on the beat, takes action within the scope of his authority against a person, based on a reasonable belief that the person might be violating the law, and supported by whatever degree of probable cause the law may require in the circumstances, such action by itself does not support an inference that the professional harbors some personal bias or prejudice against the person. Law enforcement professionals typically take action against a wide variety of persons during their careers, motivated by nothing more than a desire to carry out the duties of their offices. Even a series of actions against a person according to a plan is not enough in itself to show bias or prejudice; such activity is perfectly compatible with personally disinterested professional motivation. The negative bias or prejudice from which the law of recusal protects a party must be grounded in some personal animus or malice that the judge harbors against him, of a kind that a fair-minded person could not entirely set aside when judging certain persons or causes. See United States v. Conforte, 624 F.2d 869, 881 (9th Cir.), cert. denied, 449 U.S. 1012, 101 S.Ct. 568, 66 L.Ed.2d 470 (1980). Satisfactory evidence of bias or prejudice must show this element of personal animus or malice. The case of Berger v. United States, 255 U.S. 22, 41 S.Ct. 230, 65 L.Ed. 481 (1921), in which the Supreme Court found the affidavit of certain defendants of German extraction to be sufficient, is an instructive example. The affidavit averred facts that clearly showed, if true, that the judge regarded all Germans with hatred and contempt. The statements and actions that Balistri-eri attributes to Attorney General Warren do not demonstrate, and to our minds do not even suggest, that he was motivated by personal animus against Balistrieri. There is no showing that Warren believed that Balistrieri had done him some personal wrong for which he might have been motivated to seek retribution. There is no showing, as in Berger, that Balistrieri is a member of some national, racial, or ethnic group against which Warren was demonstrably prejudiced. True, the affidavit avers that Warren believed that Balistrieri was the head of a Mafia crime family, but there are no intemperate denunciations of the Mafia or other such evidence to show that this belief was alloyed with personal animus. Warren’s statement, quoted supra, subsection 2, gives a plausible explanation for the approach he took. While it is clear that the name “Balistrieri” came readily to Warren’s mind on that occasion, the tone of the statement as a whole is even-tempered and unemotional. We do not think that the lawsuits filed against Attorney General Warren by relatives and business associates of Balistrieri would have created personal animus. Bal-istrieri himself was not a party to the suits. Both suits were short-lived, and both were dismissed without the granting of any relief. As Attorney General, Warren was immune from personal liability for damages, and there is no indication in the affidavit that he was upset or even inconvenienced by the suits. Meritless lawsuits against public officials for actions taken in the performance of their duties are a fact of public life, and they are generally taken in stride. The affidavit therefore does not sufficiently allege facts that would convince a reasonable person that Attorney General Warren was motivated by bias or prejudice in his actions against Balistrieri interests in 1969-71, still less than such bias or prejudice persisted for ten years to give Judge Warren “a bent of mind that may prevent or impede impartiality of judgment.” 4. Section 455 Section 455 of the Judicial Code, 28 U.S.C. § 455, is the comprehensive federal recusal statute. Section 455(a) requires a judge to disqualify himself in any proceeding in which his impartiality might reasonably be questioned. Section 455(b)(1) requires disqualification when the judge has a personal bias or prejudice concerning a party, or personal knowledge of disputed evidentiary facts. The remaining subsections of § 455(b) detail several specific circumstances, such as having previously served as a lawyer in the matter in controversy, in which the judge must disqualify himself. Balistrieri contends that Judge Warren should have recused himself under § 455(a) and under the “personal bias or prejudice” part of § 455(b)(1). 4.1. Section 455(b)(1) The phrase “personal bias or prejudice” echoes the language of § 144, and there is authority that the phrase has the same meaning in both statutes. E.g. United States v. Olander, 584 F.2d 876, 882 (9th Cir.1978). We see no reason to doubt this; consequently, we shall view judicial interpretations of “personal bias or prejudice” under § 144 as equally applicable to § 455(b)(1). In particular, we think that the interpretation of “personal” as meaning “extrajudicial” applies equally to § 455(b)(1). Accord In re International Business Machines Corp., 618 F.2d 923, 928 (2d Cir.1980). We do not think, however, that § 455(b)(1) reenacts § 144. There is no hint that the strict procedural requirements of § 144 are applicable to § 455(b)(1); indeed, the language of that section strongly suggests otherwise. Section 455(b)(1) is directed to the judge and is self-executing. It requires the judge to disqualify himself if he has a personal bias or prejudice concerning a party. We think that this language imposes a duty on the judge to act sua sponte, even if no motion or affidavit is filed. Accord United States v. Story, 716 F.2d 1088, 1091 (6th Cir.1983). Section 455(b)(1) also dispenses with the requirement that the judge must take all the factual averments of the affidavit as true. The formal and procedural requirements of § 144 are safeguards against its abuse, made possible by the take-as-true requirement. We do not think that Congress, in enacting § 455(b)(1), intended to retain that requirement while doing away with the formal and procedural safeguards it thought necessary in connection with § 144. Accordingly, the judge is free to make credibility determinations, assign to the evidence what he believes to be its proper weight, and to contradict the evidence with facts drawn from his own personal knowledge. The disqualification of a judge for actual bias or prejudice is a serious matter, and it should be required only when the bias or prejudice is proved by compelling evidence. Accordingly, we think the appropriate standard of proof is the same as for § 144: whether a reasonable person would be convinced that the judge is biased. Section 455 clearly contemplates that decisions with respect to disqualification should be made by the judge sitting in the case, and not by another judge. It requires the judge to disqualify himself when any one of the statutory conditions is met. It makes no provision for the transfer of the issue to another judge. We think that appellate review of a judge’s decision not to disqualify himself, when he is asked to do so by a proper and timely motion supported by affidavits and perhaps other evidence, should not be deferential. The motion puts into issue the integrity of the court’s judgment. The absence of the requirement that the judge take the factual averments of the moving party’s affidavit as true “gives chance for the evil against which the section is directed.” See supra note 5 and accompanying text. In addition, a judge may be especially reluctant to re-cuse himself when to do so requires him to admit that his actual bias or prejudice has been proved. Accordingly, we will review decisions against disqualification under § 455(b)(1) de novo. We will evaluate the evidence for ourselves, applying the same standard as the district court. We have held that Balistrieri’s first affidavit did not compel recusal under § 144 when all its factual averments are assumed to be true. Consequently, it could not possibly compel recusal under § 455(b)(1); the standard is the same, but the take-as-true requirement no longer operates. We must then consider whether the addition of the remaining affidavits requires a different outcome. John Forbes’s credentials are far from impeccable. He is a career criminal who was serving time for burglary when he gave his affidavit. There is no independent evidence to confirm anything he said in it. But we need not rest on Forbes’s doubtful credibility; the fatal flaw in the affidavit is that it does not say that Attorney General Warren knew anything at all about Krusche’s alleged activities, still less that he ordered or authorized them. Balistrieri argues that Forbes’s remarks about illegal activities, because they were made in Warren’s presence, compel the conclusion that Warren knew of, approved, or ratified these illegal activities. We do not think such a conclusion is compelled. Even if we assume that Forbes actually made the remarks in Warren’s presence, nothing shows that Warren heard and understood them, and nothing shows that Warren would have known that Forbes was referring to illegal activities. For an undercover agent to wear a tape recorder or microphone is not, and was not then, per se illegal, and to “go in places” does not necessarily mean to enter them illegally. Because Forbes reports no response or reaction from Warren, his account is perfectly consistent with the conclusion that Warren did not know what Forbes was talking about and did not think it important enough to ask. Forbes was a bit player with a shady past, not a law enforcement professional, and the meeting was focused on something else. But even if Warren knew that Forbes was talking about illegal activity, there is nothing to show that Warren knew who Krusche was, or knew that Krusche was involved in the investigation of Balistrieri, or knew that Forbes’s illegal activities were in aid of that investigation. In sum, Forbes’s affidavit is empty of evidence that Warren was actually biased against Balistrieri, even if everything it says is true. We think that Terrence Donley’s affidavit must be taken at a steep rate of discount. Except for the vague statements in the affidavits of John J. Balistrieri and John C. Tucker, to the effect that they had confirmed certain aspects of his story through newspaper accounts, including his claim to have been an informant for the Wisconsin Department of Justice in 1971, there is nothing to support or vouch for Donley’s credibility. His affidavit includes no biographical information except his claim to have been an informant. There is no affidavit supporting his credibility by a person known to be reliable. Donley is a mystery man, totally without credentials. Furthermore, the affidavit has gross internal defects. Donley ascribes certain intemperate statements to Warren, but he does not specify the time, place, and circumstances in which they supposedly were made. Donley does say that two other named individuals were present when Warren allegedly made those statements, but no confirming affidavit from either of them is in the record. Donley’s affidavit includes unattributed hearsay and conclusions not clearly founded on Donley’s own personal, direct observations. For example, it simply does not appear how Donley would have been in a position to speak authoritatively about the budget priorities of the Attorney General. For these reasons, we conclude that Don-ley’s affidavit may be disregarded. The affidavit of Frank Balistrieri, attached to his final motion for disqualification, includes a report of an alleged remark of Judge Warren at a social gathering. But the report is hearsay and is not specific as to time, place, or source. It has the character of rumor or gossip. We think it too should be disregarded. Balistrieri’s affidavit contains no other factual averments not already included in previous affidavits. We thus conclude that all the affidavits submitted with all the motions for disqualification did not require, when considered together, that Judge Warren recuse himself under § 455(b)(1). Because the charge of actual bias or prejudice in a judge goes to the heart of the integrity of the judicial process, we have gone a step further in our review and have examined all the pretrial orders of Judge Warren in the record for unmistakable indications that his rulings were affected by bias or prejudice against Balistri-eri. We have found no such indications. We also note that several of the motions denied by Judge Warren, presumably those in which Balistrieri had the greatest interest, were resubmitted to Judge Evans before and after trial, and that Judge Evans made independent rulings on them. 4.2. Section 455(a) Section 455(a) of the Judicial Code, 28 U.S.C. § 455(a), is not intended to protect litigants from actual bias in their judge but rather to promote public confidence in the impartiality of the judicial process. See H.R.Rep. No. 93-1453, 93d Cong., 2d Sess. (1974), reprinted in 1974 U.S.Code Cong. & Ad.News 6351, 6354-55. It is directed against the appearance of partiality, whether or not the judge is actually biased. See United States v. Murphy, 768 F.2d 1518, 1540 (7th Cir.1985); SC A Services, Inc. v. Morgan, 557 F.2d 110, 116 (7th Cir.1977). We have previously reviewed the denial of a motion to disqualify under § 455(a) under an abuse-of-discretion standard. See S.J. Groves & Sons v. International Brotherhood of Teamsters, 581 F.2d 1241, 1248 (7th Cir.1978). But the analysis of our recent case, United States v. Murphy, 768 F.2d 1518 (7th Cir.1985), implies that such denials are not properly reviewable on appeal at all. It is a fundamental principle of appellate review that unless an error affects the substantial rights of the appellant, it is not a basis of reversal. 28 U.S.C. § 2111; Fed.R.Crim.P. 52(a). As we pointed out in Murphy, 768 F.2d at 1539, if a judge proceeds in a case when there is (only) an appearance of impropriety in his doing so, the injury is to the judicial system as a whole and not to the substantial rights of the parties. The parties in fact receive a fair trial, even though a reasonable member of the public might be in doubt about its fairness, because of misleading appearances. We would hesitate to hold that the denial of a motion to disqualify under § 455(a) is never reversible error if the moving party would be left with no recourse when a judge denies such a motion. We would be depriving ourselves of any means of supervising the administration of § 455(a) in the district courts. But we have held that a writ of mandamus is an appropriate remedy against a judge who refuses to recuse himself when required to do so under that statute. Pepsico, Inc. v. McMillen, 764 F.2d 458, 460 (7th Cir.1985) (granting writ); SCA Services, Inc. v. Morgan, 557 F.2d 110, 117-18 (7th Cir.1977) (per curiam) (same). The writ of mandamus is the vehicle by which we may exercise our supervisory powers over the district courts with respect to § 455(a). To require a timely petition for a writ of mandamus as the sole remedy serves another important purpose: that of preventing injury to the public perception of the judicial system before it has a chance to occur. If a party is deprived of his substantial rights in a trial before an actually biased judge, the harm can be remedied (though not costlessly) by a new trial before an unbiased judge. But the harm to the public’s perception of the judicial system when a judge who appears to be biased proceeds in a case is more difficult to correct. Prevention in such circumstances is clearly preferable to attempts to cure. Accordingly, we hold that when a judge denies a motion to disqualify himself under § 455(a), the moving party’s sole recourse is to apply to this court immediately for a writ of mandamus. We therefore shall not review Judge Warren’s several denials of Balistrieri’s motions under § 455(a). B. Hearing Under Franks v. Delaware On October 20, 1979, the district court entered an order permitting electronic surveillance at Snug’s Restaurant and Leonardo’s Pasta House. In support of its motion seeking the order the government submitted a 110-page affidavit of Agent Michael De Marco setting forth evidence that Balistrieri and his associates were engaged in extortion, illegal gambling, and the murders and attempted murders of suspected informants. The electronic surveillance produced evidence that the government intended to introduce at Balistrieri’s trial. After indictment, Balistrieri moved for an evidentiary hearing, pursuant to Franks v. Delaware, 438 U.S. 154, 98 S.Ct. 2674, 57 L.Ed.2d 667 (1978), on the question whether the electronic surveillance evidence should be suppressed because the government made false statements in its affidavit knowingly and intentionally, or with reckless disregard for the truth. On July 6, 1982, the magistrate denied the motion. Balistrieri appealed to the district court, which affirmed the magistrate on October 29, 1982. In Franks v. Delaware, the Supreme Court held that where the defendant makes 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 was 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. If the defendant proves his contention at the hearing, and if the affidavit’s remaining content is insufficient to establish probable cause, then the search warrant must be voided and the fruits of the search excluded. Id. at 156, 98 S.Ct. at 2676. In his motion for a Franks hearing, Bal-istrieri charged that Agent De Marco’s affidavit contained a number of knowingly false statements purporting to report statements made by Balistrieri in the presence of undercover agent Gail Cobb and others. Balistrieri claimed that he had never made the statements attributed to him and submitted his own affidavit and the affidavits of other persons alleged to have been present when the statements were supposed to have been made. Each affiant stated that no such statements had been made. The magistrate held that the statements in question were material; without them the De Marco affidavit would not contain sufficient probable cause. But he denied the motion nevertheless, because Balistrieri had not made a sufficiently substantial preliminary showing that the statements were knowingly and intentionally false or were made with reckless disregard for their truth or falsity. The magistrate reasoned that counteraffidavits by those named as participants in the alleged conversations were not enough, because the agent had a greater incentive to be truthful than the alleged participants. The agent risked the exclusion of all evidence obtained as a re-suit of the surveillance order, while the counteraffiants were subject only to the penalties for false swearing. He concluded that “Franks” requires more than a ‘swearing contest’ before a hearing is mandated.” We are troubled by the magistrate’s reasoning, but we need not consider whether Balistrieri made a sufficiently substantial preliminary showing. We hold that the statements Balistrieri challenges were not material; to the extent that the magistrate and the district court held otherwise, their holdings were erroneous. The statute governing procedures for the interception of wire or oral communications is 18 U.S.C. § 2518. Under the statute the judge, before he may approve or authorize the interception of wire or oral communications, must determine on the basis of the facts submitted by the applicant that, inter alia: (a) there is probable cause for belief that an individual is committing, has committed, or is about to commit a particular offense enumerated in section 2516 of [Title 18]. The De Marco affidavit reports extensive, detailed information obtained from numerous confidential informants of proven reliability, from surveillance by Special Agents, from reports of Special Agents working under cover, and from previous court-authorized wire taps and surreptitious recordings. Disregarding the statements that Balistrieri contends are false, we think that the evidence presented in the affidavit is sufficient to establish probable cause to believe that Frank Balistrieri was the head of an association of individuals devoted to criminal activities in Milwaukee, that he authorized the murders of August Palmisano, August Maniaci, and Vincent Maniaci (the last of whom escaped death when the bomb failed to detonate), that he owned an illegal sports gambling business operated by Sam Librizzi, and that he expanded his vending machine business and took over other businesses by unlawful means. Probable cause is not proof beyond a reasonable doubt or proof by a preponderance of the evidence. Illinois v. Gates, 462 U.S. 213, 103 S.Ct. 2317, 2330, 76 L.Ed.2d 527 (1983). The information in the affidavit need establish only a “fair probability,” by practical common-sense standards, that the offenses alleged have been, are being, or will be committed. Id. 103 S.Ct. at 2332. The De Marco affidavit amply meets this test without the statements that Balistrieri contends are false. C. Speedy Trial Act Balistrieri contends that he is entitled to a new trial because he was not afforded the minimum thirty days preparation time guaranteed by the Speedy Trial Act. We shall consider this question in connection with the appeal of Dennis Librizzi, on whose arguments Balistrieri relies. See infra sec. IV D. D. Presence of Unauthorized Person Before Grand Jury On August 18, 1983, a grand jury returned a superseding indictment, and the district court signed the government’s order for dismissal of the original indictment. Balistrieri moved for the dismissal of the superseding indictment, on grounds that the Strike Force attorneys who appeared before the grand jury had no authority to do so. The district court denied this motion. Rule 6(d) of the Federal Rules of Criminal Procedure reads as follows: (d) Who May Be Present. Attorneys for the government, the witness under examination, interpreters when needed and, for the purpose of taking the evidence, a stenographer or operator of a recording device may be present while the grand jury is in session, but no person other than the jurors may be present while the grand jury is deliberating or voting. Rule 54(c) defines “attorney for the government” to include the Attorney General, an authorized assistant of the Attorney General, a United States Attorney, and an authorized assistant of a United States Attorney. John Franke and Mark Vogel conducted the grand jury proceedings leading to the superseding indictment. Franke and Vogel were not assistant United States Attorneys but “special attorneys” employed by the Organized Crime and Racketeering Section of the Criminal Division of the Department of Justice. They were assigned to assist the United States Attorney for the Eastern District of Wisconsin in investigating and prosecuting this case. Thus, if they were “attorneys for the government” within the meaning of Rule 6(d), it was because they were “authorized assistants of the Attorney General” under Rule 54(c). Balistrieri argued below that Franke and Vogel were not “authorized assistants of the Attorney General” because they did not have the authorization provided for by 28 U.S.C. § 515(a), which reads: (a) The Attorney General or any other officer of the Department of Justice, or any attorney specially appointed by the Attorney General under law, may, when specifically directed by the Attorney General, conduct any kind of legal proceeding, civil or criminal, including grand jury proceedings and proceedings before committing magistrates, which United States attorneys are authorized by law to conduct, whether or not he is a resident of the district in which the proceeding is brought. In response, the government submitted letters of authorization and other documents evidencing the authority of Franke and Vogel. A letter dated November 7, 1979, from Philip B. Heymann, Assistant Attorney General for the Criminal Division of the Department of Justice, to Mark J. Vogel, contains the following text: As an attorney for the Government employed full time by the Department of Justice and assigned to the Criminal Division, you are hereby authorized and directed to file informations and to conduct in the Eastern District of Wisconsin and any other judicial district any kind of legal proceedings, civil or criminal, including grand jury proceedings and proceedings before United States Magistrates, which United States Attorneys are authorized to conduct. You may file a copy of this letter with the Clerk of the District Court to evidence this authorization. Balistrieri concedes in this court that under our holding in Infelice v. United States, 528 F.2d 204 (7th Cir.1975), this letter was sufficiently specific to establish Vogel’s authority to appear before the grand jury. The letter to Franke was from Stephen S. Trott, Assistant Attorney General for the Criminal Division, and bore a date of August 23, 1983, five days after the return of the superseding indictment. It read: This letter is to evidence your appointment as an attorney for the Government, employed full time by the Department of Justice, and assigned to the Criminal Division. Since March 15, 1982, you have been and continue to be authorized and directed to file informations and to conduct in the Eastern District of Wisconsin and any other judicial district any kind of legal proceedings, civil or criminal, including grand jury proceedings and proceedings before United States Magistrates, which United States Attorney are authorized to conduct. You may file a copy of this letter with the Clerk of the District Court to evidence this authorization. Balistrieri contends that this letter is not a letter of authorization; it simply recites that Franke had been appointed an attorney for the government and that since March 15,1982, he had been authorized and directed to appear before the grand jury. He points out that the letter does not recite how, where, or by whom that authorization or direction was made. An unsworn letter merely stating that authorization was previously given, he contends, is not adequate proof of authorization. Section 515(a) was enacted in 1906 in order to overrule legislatively United States v. Rosenthal, 121 F. 862 (C.C.S.D.N. Y.1903), which held that only the United States Attorney for the district or one of his assistants could present a matter to the grand jury. United States v. Morris, 532 F.2d 436 (5th Cir.1976); In re Pérsico, 522 F.2d 41 (2d Cir.1975). According to the report of the Judiciary Committee in favor of passage, [t]he purpose of this bill is to give to the Attorney General, or to any officer in his Department, or to any attorney specially employed by him, the same rights, powers and authority which district attorneys [United States Attorneys] now have or may hereafter have in presenting and conducting proceedings before a grand jury or committing magistrate. H.R.Rep. No. 2901, 59th Cong., 1st Sess. 1-2 (1906), as quoted in Morris, 532 F.2d at 440. While the principal purpose of the statute was to empower the Attorney General and his special employees to appear before grand juries and magistrates, Congress also wanted to protect the treasury from excessive expenses and unwarranted claims incident to the appointment of special counsel and to preserve the traditional role of district (now United States) attorneys as the primary representatives of the government before grand juries. Pérsico, 522 F.2d at 60. The restrictive features of the statute are directed to those ends; there is no evidence that Congress intended those features as safeguards for the benefit of those whose indictment might be sought. Consequently, § 515(a) has generally been constructed liberally in favor of the validity of indictments. Id. at 61. Letters appointing or commissioning special attorneys have been extensively attacked as overly broad, and in virtually every case the appointment has been upheld. In Infelice v. United States, 528 F.2d 204 (7th Cir.1975), we noted cases holding that the failure to specify the statute under which the special attorney was to act was not fatal, that the failure to specify the names of the persons to be investigated or prosecuted was of no consequence, and that no reason need be stated for the appointment. Id. at 206-07. See also Pérsi-co, 522 F.2d at 62-64. Balistrieri, of course, does not contend that Franke’s letter of appointment is over-broad but that it is totally absent. We must confront two questions that are apparently of first impression: (1) can a special attorney be validly appointed under § 515(a) without a letter of appointment or written commission, and if so, (2) can his authority be proved by a letter from the Assistant Attorney General for the Criminal Division certifying that he has been authorized from a certain date in the past? We do not know whether Franke’s letter of authorization was never issued or was issued and lost. If such a letter is essential to the authorization, it would make a difference. On that assumption, if the letter was never issued, there was never any authorization, but if it was issued and later lost, there was authorization that might be proved by other evidence. In the absence of evidence to the contrary, we shall assume that no letter was issued. Nevertheless, we hold that a letter of authorization is not essentia] to the validity of an appointment under § 515(a). The statute does not in terms require written authorization, and the general policy of liberally construing the statute in favor of the validity of indictments inclines us not to add such a provision to it. We might think otherwise if the commissions of special attorneys had to be precisely and narrowly drawn, meticulously tailor-made for carefully limited purposes. In that event it might be too difficult to reconstruct the authority of a special attorney without a written commission, and too easy to mold the authority afterwards to fit the special attorney’s activities. But the law clearly favors broadly drawn commissions, relying on other institutional safeguards to hold special attorneys in check. See Pérsi-co, 522 F.2d at 51-52. The question now becomes whether Franke was in fact authorized to appear before the grand jury that returned the superseding indictment. We are persuaded that the evidence submitted by the government is sufficient to establish that he was authorized. The letter of August 23, 1983, stating that Franke has been authorized since March 15, 1982, is from the Assistant Attorney General for the Criminal Division, and Balistrieri makes no challenge to that official’s authority to make such appointments as an original matter. Indeed, Vo-gel’s letter, which Balistrieri no longer contests, is also from the Assistant Attorney General for the Criminal Division. That the letter does not say how, where, or by whom Franke was originally authorized appears to us immaterial. That the letter is not notarized also appears immaterial; it is clearly in the standard form used by the Criminal Division for letters of authorization, and Balistrieri does not contend that the signature is a forgery. The letter to Vogel was not notarized. If there were countervailing evidence or even any reason to suspect that Franke really was not authorized when he appeared before the grand jury, we might require harder evidence. But there is nothing to suggest that the absence of an original letter of authorization was anything more than an administrative oversight. Furthermore, there is evidence in the record to corroborate Franke’s prior authorization. On March 17, 1982, Franke executed a duly notarized Appointment Affidavit on Standard Form 61, showing the position to which he was appointed to be Special Attorney and the date of appointment to be March 15, 1982. The affidavit includes, among other things, Franke’s oath of office. Of course, we do not commend the government’s procedure with regard to Franke’s authorization. Clearly, contemporaneous letters of authorization are preferable to retrospective proof, however convincing. But under the unusual circumstances of this case, we hold that Franke’s authorization was sufficiently proved and that the superseding indictment may stand. E. Sufficiency of the Evidence Balistrieri contends that the evidence was insufficient to sustain his convictions. The standard we apply is whether, after viewing the evidence in the light most favorable to the prosecution, any rational trier of fact could have found the essential elements of the crimes charged beyond a reasonable doubt. Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 2789, 61 L.Ed.2d 560 (1979); United States v. Redwine, 715 F.2d 315, 319 (7th Cir.1983), cert. denied, — U.S. -, 104 S.Ct. 2661, 81 L.Ed.2d 367 (1984). 1. Count 2 — The 1977 Football Season To convict Balistrieri of Count 2, the government had to prove that he conducted, financed, managed, supervised, directed, or owned a gambling business in 1977 that (i) was a violation of the law of Wisconsin, (ii) involved five or more persons, and (iii) had a gross revenue of $2,000 in any single day. 18 U.S.C. § 1955. We proceed from the premise that the government proved that Salvatore “Sam” Librizzi operated a football gambling business during the 1977 football season that met conditions (i), (ii), and (iii). Balistrieri does not contest this premise. The government’s theory was that Balistrieri was the owner of the business. In support of this theory the government offered the testimony of Joseph Pistone, a Special Agent of the Federal Bureau of Investigation, who worked undercover as part of the Strike Force investigation. Pistone testified that on Sunday, August 27, 1978, he participated in a conversation with Frank Balistri-eri and Steve DiSalvo at the Peppercorn Lounge in Milwaukee, during which Frank Balistrieri said that Steve DiSalvo was in charge of his bookmaking operation, and he was looking — Frank Balistri-eri was looking for an individual to oversee the day-to-day operation, because the person that was running it last year, by the name of Sam, did not tend to business and wasn’t doing a good job and he was looking for someone that he could trust to run the daily, the day-to-day operation for the upcoming football season. We think that a reasonable jury could have believed this testimony and could have inferred from it, beyond a reasonable doubt, that Frank Balistrieri owned a football gambling business in 1977 that was operated by someone named “Sam.” There was further evidence that “Sam” was Sam Librizzi. FBI agents observed Sam Librizzi meeting in a hospital parking lot with Steve DiSalvo on three separate occasions in October 1976. Following one of these meetings, DiSalvo was observed driving directly to Frank Balistrieri’s house. In September 1978 Balistrieri was shown photographs of one of these meetings during a grand jury proceeding. Gail Cobb, a Special Agent for the FBI who had also worked undercover, testified that in a conversation among Frank Balistrieri, Peter Balistrieri, and Steve DiSalvo just after the proceeding, Peter said to Steve, “You got a problem,” and then Frank told him that they had pictures of Steve at the hospital— meeting at the hospital, and Steve gave the name of the hospital which I don’t recall, and they said, “Yes, they got pictures of you there where you picked up the money.” Cobb also testified that in this conversation Frank Balistrieri mentioned Sam Librizzi by name as the person with whom DiSalvo had met. A reasonable jury could have believed all of this testimony and could have inferred from it, beyond a reasonable doubt, that the “Sam” to whom Balistrieri referred in the Peppercorn conversation was Sam Librizzi, and thus that Balistrieri was the owner of Sam Librizzi’s football gambling business in 1977. Balistrieri argues that because Sam Li-brizzi’s meetings with DiSalvo were for unknown purposes and took place in 1976, there was no evidence tying Balistrieri to Sam Librizzi’s 1977 gambling operation. We disagree. Given the admissions in the Peppercorn conversation, the jury needed only evidence from which it could find beyond a reasonable doubt that the “Sam” Balistrieri referred to was Sam Librizzi, and we think the evidence provided was sufficient for that purpose. 2. Count 3 — The 1979 Football Season Count 3 charged Balistrieri with violating 18 U.S.C. § 1955 during the 1979 football season. The evidence consisted primarily of the materials obtained in a warrant-authorized search of Balistrieri’s home on March 5, 1980, together with expert testimony as to the significance of those materials. They included a “charting sheet” and “bet sheets” of the kind used in a bookmaking operation. These sheets were written in Sam Librizzi’s hand. The expert testified that they related to the 1979 football season. The government also introduced a recorded conversation between Frank Balis-trieri and Sam Librizzi that took place on January 10, 1980. Librizzi delivered a large sum of money to Balistrieri. They talked about people who had not paid and about the level of betting on certain games. In the expert’s opinion Librizzi was reporting to Balistrieri'part of the previous season’s wagering activity. The expert also expressed his opinion that Frank Balistrieri was the owner or a partner in the gambling business run by Sam Librizzi. We think that this evidence is sufficient to enable the jury to conclude that Balistrieri owned a football gambling business during the 1979 football season that violated Wisconsin law. According to the expert, the sheets seized in the search of Balistrieri’s house reflected the acceptance of more than $47,-000 in bets on October 14, 1979. This is sufficient to prove that the business had a gross revenue of $2,000 in a single day. The difficult question is whether the government proved that five or more persons were involved. The government’s expert testified that the evidence showed that Balistrieri, Sam Librizzi, John Pisciune, Carl Micelli, and a partner of Micelli known as “Matches” were involved. Pisciune’s involvement was shown by his recorded conversation with Sam Librizzi and by the fact that some of the betting sheets bore the initials “J.P.” at the top, which, according to the expert, identified a writer for the operation. The expert identified Micelli and “Matches” as writers on the basis of remarks in the Balistrieri-Librizzi conversation together with the fact that they had been writers in previous years. Balistrieri argues that Pisciune was acquitted and so cannot count as one of the five, and that Micelli and “Matches” were the same person. But the jury could have acquitted Pisciune through lenity while believing him guilty; his acquittal does not bar the use of evidence of his involvement against Balistrieri. See United States v. Powell, — U.S.-, 105 S.Ct. 471, 477, 83 L.Ed.2d 461 (1984). Furthermore, even if Pisciune was not “J.P.,” the evidence showed that someone identified by the initials “J.P.” was a writer, and he may be counted. There was evidence to show that Micelli had a partner, that both were writers for the business and occupied the same office, and that both reported wagers to Sam Li-brizzi, who recorded them in an account labeled “Matches.” The jury could have believed this evidence; whether “Matches” was the nickname of Micelli or his partner is irrelevant. Balistrieri argues that even if the jury could have found that five people were involved and that gross revenues exceeded $2,000 on at least one day, there is nothing to show that five people were involved on such a day. But the statute does not require proof that five people were involved on a $2,000 day, and we have found no case that so holds, certainly not United States v. Gresko, 632 F.2d 1128, 1133-34 (4th Cir.1980), cited to us by Balistrieri. We conclude that the evidence was sufficient to support the jury’s verdict on Count 3. 3. Count 1 — The Conspiracy Count Count 1 charged Balistrieri with conspiring to commit offenses in violation of 18 U.S.C. § 1955, beginning on or before September 1, 1977, and continuing until April 18, 1980. As overt acts the indictment alleged the conduct charged in Counts 2, 3, and 4, as well as several specific incidents of gambling activity. The federal crime of conspiracy has two basic elements: an agreement between two or more persons to commit a crime, and an overt act in furtherance of the illegal agreement. 18 U.S.C. § 371. Balistrieri does not contend that no agreement was proved, and indeed there was evidence to show that Balistrieri agreed with Sam Librizzi as early as 1977 that Librizzi would operate Balistrieri’s sports gambling business. Balistrieri argues rather that because the evidence in support of Counts 2 and 3 is insufficient, and because he was acquitted on Count 4, no overt act was proved. But we have held that the evidence in support of Counts 2 and 3 is sufficient, and his acquittal of Count 4 does not require reversal of the conspiracy conviction. See United States v. Isaksson, 744 F.2d 574 (7th Cir.1984) (government not required to prove all overt acts charged; proof of one can suffice). Balistrieri argues that even if there was evidence of a conspiracy involving Balistri-eri, the evidence shows multiple conspiracies at best and not the single conspiracy charged in the indictment. He contends that these conspiracies involved different persons and different periods of time, specifically the 1977 football season, the 1979 football season, and the 1980 basketball season. We think the jury could have inferred that there was a single ongoing conspiracy. Continuity of a conspiracy does not require perfect continuity of membership. Some members may join or drop o