concurring.
I join without reservation in all portions of Judge Sloviter’s opinion except for Parts II.A.1. and II.A.2. In Part II.A.1., Judge Sloviter’s follows our opinion in United States v. Continental Group, Inc., 603 F.2d 444 (3d Cir.1979), cert. denied, 444 U.S. 1032, 100 S.Ct. 703, 62 L.Ed.2d 668 (1980), and holds that the district court was not required to hold an in limine hearing to determine the sufficiency of nonhearsay evidence (“evidence aliunde”) to establish a conspiracy and connect a defendant to it. In Part II.A.2., also following Continental Group, Judge Sloviter holds that the district court was not required to make explicit its conclusion that there was a preponderance of evidence aliunde because that conclusion could be inferred from the court’s decision to submit the case to the jury.
These holdings relate to the trial judge’s evidentiary screening function, now codified in Fed.R.Evid. 104(a). Rule 104(a) allocates the determination of preliminary questions concerning the admissibility of evidence to the court. Proper performance of that screening function is essential to the fair conduct of conspiracy trials, especially of complex, multi-count conspiracy indictments. Because this panel is bound by our holding in Continental Group, I concur in the result in Parts II.A.1. and II.A.2. I write separately, however, to express my belief that the Continental Group rule sweeps too broadly. In my view, this Court should no longer be content to infer a finding of sufficient evidence aliunde from the district court’s decision to submit the case to the jury, at least where that finding requires the resolution of credibility questions. Moreover, I believe that this Court should counsel the district courts that in limine hearings, while not required, are at least preferred in cases where the defendant wishes to attack the credibility of a witness whose credibility is critical to the court’s evidentiary determination and the circumstances of the trial itself (typically a multi-count, multi-defendant conspiracy trial) impairs that strategy.
*268I.
To understand the screening function of the trial judge, it is helpful to refer to Judge Friendly’s opinion in United States v. Geaney, 417 F.2d 1116 (2d Cir.1969), cert. denied, 397 U.S. 1028, 90 S.Ct. 1276, 25 L.Ed.2d 539 (1970), which was adopted by this Court in United States v. Bey, 437 F.2d 188 (3d Cir.1971), and its progeny, including Continental Group. Judge Friendly started with the proposition established in a number of opinions by Judge Learned Hand1 “that it was for the judge to determine whether there was sufficient evidence that the defendant against whom [co-conspirator] declarations were offered had engaged in a ‘concerted mutual venture’ with the declarant.” Id. at 1119. Then, noting that Judge Hand’s opinions left in doubt the quantum of evidence that would suffice, Judge Friendly observed:
The circumstance that in a conspiracy trial the preliminary issue on the admissibility of evidence coincides with the ultimate one of the defendant’s guilt should not cause the trial judge to abdicate his traditional duty to decide those issues of fact which determine the applicability of a technical exclusionary rule. When the matter is viewed from the standpoint of the trial judge, it may be hard to say more than that he must satisfy himself of the defendant’s participation in a conspiracy on the basis of the non-hearsay evidence. ... Setting the standard that high avoids the risk that the requirement of independent evidence will be rendered “virtually meaningless,” as some courts are said to have done.
Id. at 1120 (citations omitted).
After observing that the practicalities of a conspiracy trial might require hearsay to be admitted “subject to connection,” Judge Friendly announced the rule that we have followed:
[T]he judge must determine, when all the evidence is in, whether in his view the prosecution has proved participation in the conspiracy, by the defendant against whom the hearsay is offered, by a fair preponderance of the evidence independent of the hearsay utterances. If it has, the utterances go to the jury for them to consider along with all the other evidence in determining whether they are convinced of defendant’s guilt beyond a reasonable doubt. If it has not, the judge must instruct the jury to disregard the hearsay or, when this was so large a proportion of the proof as to render a cautionary instruction of doubtful utility, ... declare a mistrial if the defendant asks for it.
Id. (footnote omitted).
Thus, the Geaney/Continental Group rule imposes upon the trial judge an evidentiary screening function that is essential to the fairness of the trial. What is sometimes overlooked in the rule’s formal recitation, however, is that the preponderance finding differs from the prima facie test it replaces: 2 The preponderance test requires the judge to determine the credibility of *269witnesses and to make a finding based on a fair assessment of the evidence, whereas the credibility of witnesses need not be considered under the prima facie test. The Geaney/Continental Group rule establishes that the court is to apply a preponderance test, rather than a reasonable doubt standard, in finding that a conspiracy exists and that a defendant is connected to it. Judge Weinstein thinks that this test is not stringent enough.3 This Court has eschewed a reasonable doubt standard, and it has rejected Judge Weinstein’s position (adopted only by the Sixth Circuit, see United States v. Vinson, 606 F.2d 149 (6th Cir.1979), cert. denied, 444 U.S. 1074, 100 S.Ct. 1020, 62 L.Ed.2d 756 (1980)) that the trial judge should consider the hearsay testimony in making the threshold determination. However, precisely the concerns articulated by Judge Weinstein suggest that the preponderance standard be applied rigorously, with explicit findings by the district court both on the credibility of nonhearsay witnesses and the sufficiency of the evidence.
My concern on this record is with the case against appellant Stillman. The critical evidence aliunde as to Stillman’s participation in the conspiracy was the testimony of Mr. Welkie, a co-conspirator turned government informant. It was Welkie who supplied the testimony about the crucial transaction linking Stillman to the conspiracy (i.e., the meeting in July 1980 at the Detroit Hyatt Regency, involving Ghassan, Dahabi, Welkie, Stillman, and an unidentified man, where, according to Welkie, Stillman directed him to give a package containing heroin to the unidentified man).
Stillman mounted a considerable attack on Welkie’s credibility. He attempted to establish that Welkie had used more than two grams of heroin before and during the meeting at the Hyatt. He also attempted to show that Welkie had given fatally inconsistent statements about that meeting, having asserted in his statement to Agent Schmotzer that it had been Ghassan, not Stillman, who had directed that the package be given to the unidentified man. Still-man sought to attack Welkie’s credibility on other grounds as well.4 The district court excluded much of the proffered impeach*270ment. And yet, despite the centrality of Welkie’s credibility to the preponderance determination, the district court made no explicit credibility findings.
It seems to me that the district court misapprehended the scope of its screening responsibilities. The majority concedes that “cross-examination of Welkie was limited in some respects” but asserts that “any additional cross-examination by Stillman would have been merely cumulative.” Ante. I am doubtful of that proposition, see supra note 4, but more important, it is unclear that the district court assessed Welkie’s credibility on the evidence presented. The majority refuses to “assume that the [district] court ignored a portion of the evidence before it simply because its ultimate determination was unfavorable to the appellant.” Ante. In my view, this Court should not be forced to infer from an ultimate conclusion that the district court properly considered evidence in performing its screening function. I would modify Continental Group to require explicit findings, at least where credibility is important to the evidence aliunde determination. We do not permit implied findings in bench trials under Fed.R.Civ.P. 52(a), and there is no reason for a different rule for a critical phase of a criminal case, as the preponderance determination under Rule 104(a) clearly is.
II.
I turn to the procedural setting in which the credibility issues must be tested. If, as the preponderance test requires, evidentiary findings are to be made rationally and fairly in cases where credibility is at issue, the judge must allow adequate opportunity for impeachment of the persons or documents supplying evidence aliunde. And yet in a multi-count, multi-defendant conspiracy trial, with a jury in the box, the circumstances may not permit that opportunity. I recognize that Judge Sloviter, either in the text of her opinion or by her disposition of the myriad claims alleged by Stillman and catalogued in the opinion’s appendix, has rejected the contention that the district court erred in excluding the proffered impeachment evidence. It is indisputable that the district court has broad discretion to exclude probative evidence on the basis of the factors listed in Fed.R.Evid. 403, including unfair prejudice to co-defendants. In my view, however, the inquiry does not end with the conclusion that the district court did not abuse its discretion by its evidentiary rulings.
Under Fed.R.Evid. 104(a), a court “is not bound by the Rules of Evidence except those with respect to privileges” in determining the admissibility of evidence. One reason for the in limine hearing procedure is to enable the court to consider evidence bearing upon the preponderance finding but not admissible at trial. In limine hearings thus give the court the ability to conduct a hearing out of the jury’s presence on the threshold question whether there is a preponderance of evidence aliunde linking a particular defendant with a conspiracy, without prejudicing either him or his codefendants.
In limine hearings are flexible; they need not be full-dress, pretrial reviews of the evidence.5 For example, it generally causes little disruption or loss of time for the trial judge to recess the trial and take sufficient testimony out of the hearing of the jury to complete the record.
*271I do not suggest that Rule 104(a) requires the district court to receive inadmissible evidence. That rule makes it clear, however, that a court conducting an in limine hearing is not bound by the Rules of Evidence and may consider inadmissible evidence in making its determination. Indeed, the district court might well have allowed Stillman to develop his excluded impeachment evidence in this case if our prior opinions had instructed that it is preferable for a court to hold an in limine hearing when there is a serious credibility problem in connection with an evidence aliunde determination, or when proffered impeachment evidence might unduly prejudice a co-defendant. As I have noted, multi-count, multidefendant conspiracy trials often impair a defendant’s impeachment strategy. The district court here should have had the impetus from this Court to at least consider an in limine hearing, and I believe that this Court should counsel the district courts that this is the preferred course in such situations. I would not make it an absolute requirement; I am satisfied with the wise exercise of discretion by the district courts in this Circuit.
III.
In sum, the proceedings in this case would have been fairer to Stillman if the district court had recessed to conduct an in limine hearing to further explore Welkie’s credibility. Moreover, the integrity of that exploration would have improved markedly if the district court had been required by decisions of this Court to make explicit findings. I believe that this Court, in the interest of improving the administration of justice in this Circuit, should modify the Continental Group rule accordingly.
SUR PETITION FOR REHEARING
Before SEITZ, Chief Judge, and ALDI-SERT, ADAMS, GIBBONS, HUNTER, WEIS, GARTH, HIGGINBOTHAM, SLOVITER and BECKER, Circuit Judges.The petition for rehearing filed by Appellant, Marshall Stillman, in the above entitled case having been submitted to the judges who participated in the decision of this court and to all the other available circuit judges of the circuit in regular active service, and no judge who concurred in the decision having asked for rehearing, and a majority of the circuit judges of the circuit in regular active service not having voted for rehearing by the court in banc, the petition for rehearing is denied. Because Judge Becker believes that United States v. Continental Group, Inc., 603 F.2d 444, 457 (3d Cir.1979), cert. denied, 444 U.S. 1032, 100 S.Ct. 703, 62 L.Ed.2d 668 (1980), should be reconsidered by the in banc court, he would grant rehearing .
. United States v. Dennis, 183 F.2d 201, 230-231 (2d Cir. 1950), aff’d, 341 U.S. 494, 71 S.Ct. 857, 95 L.Ed. 1137 (1951); United States v. Pugliese, 153 F.2d 497, 500 (2d Cir.1945); United States v. Nardone, 127 F.2d 521, 523 (2d Cir.), cert. denied, 316 U.S. 698, 62 S.Ct. 1296, 86 L.Ed. 1767 (1942); United States v. Renda, 56 F.2d 601, 602 (2d Cir.1932) (per curiam) (attributed to Judge Hand).
. Only the Ninth Circuit even nominally retains the “prima facie” standard of proof. Judge Weinstein notes that this standard makes sense only in cases where the jury decides whether there is sufficient evidence aliunde to admit co-conspirators’ statements into evidence, while the court only makes the initial decision to let the case go to the jury on the basis of a prima facie determination. 1 Weinstein & Berger, Evidence ¶ 104[05], at 104-55 (1982). However, the Ninth Circuit characterizes the standard as requiring the government to adduce sufficient, substantial evidence aliunde of a conspiracy and of the defendant’s connection thereto. See United States v. Perez, 658 F.2d 654 (9th Cir.1981); United States v. Zemek, 634 F.2d 1159 (9th Cir. 1980), cert. denied, 450 U.S. 916, 101 S.Ct. 1359, 67 L.Ed.2d 341 (1981); cases cited in 1 Weinstein & Berger, supra, ¶ 104[05] n. 54. The Fifth, Tenth and District of Columbia Circuits also require the district court as a preliminary matter to find “substantial evidence” of the existence of a conspiracy and the defendant’s membership in it. The Fifth and Tenth Circuits require in addition a preponderance finding at the close of all testimony. See United States v. James, 590 F.2d 575 (5th Cir.) (en banc), cert. denied, 442 U.S. *269917, 99 S.Ct. 2836, 61 L.Ed.2d 283 (1979); United States v. Petersen, 611 F.2d 1313 (10th Cir. 1979), cert. denied, 447 U.S. 905, 100 S.Ct. 2986, 64 L.Ed.2d 854 (1980); United States v. Jackson, 627 F.2d 1198 (D.C.Cir.1980). The other circuits, including this one, have adopted the fair preponderance of the evidence standard for the district court’s preliminary determination. See cases cited in 1 Weinstein & Berger, supra, ¶ 104[05] n. 44.
. [T]he fair and practicable method of providing protection to the defendant without violating the letter or spirit of the Rules lies in insisting on a stringent standard of proof.... Only if the court is itself convinced to a high degree of probability — considering hearsay as well as nonhearsay evidence — of the conspiracy, defendant’s membership, and that the statement was made during the course of, and in furtherance thereof, should it admit.
1 Weinstein & Berger, supra, ¶ 104[05], at 104-43 to -44 (footnote omitted).
. Welkie had also given a statement to his probation officer. Stillman moved for its production pursuant to 18 U.S.C. § 3500 (1976) (governing the production by the government of statements of its witnesses) as evidence tending to impeach Welkie. The district court held the statement “not discoverable in any event. That is a private paper prepared for the use of the Court.” According to Stillman, the district court was required at least to compare Welkie’s statement to his probation officer with his trial testimony, see United States v. Cyphers, 553 F.2d 1064, 1068-69 (7th Cir.), cert. denied, 434 U.S. 843, 98 S.Ct. 142, 54 L.Ed.2d 107 (1977); United States v. Figurski, 545 F.2d 389, 391-92 (4th Cir.1976). Stillman also sought to learn whether the DEA informant file on Welkie contained other versions of the event. The court quashed defendant’s subpoenas of that file and refused to examine it in camera or to seal it for transmittal to this Court.
Only portions of Schmotzer’s interrogation of Welkie on August 27 were tape recorded. During the cross-examination of Welkie, Stillman sought to obtain Schmotzer’s notes of the unrecorded portions of the interview. The court held that the notes were not Welkie’s “statements” under 18 U.S.C. § 3500 and ordered them sealed until after Schmotzer testified. The notes were then furnished to counsel, but when Welkie was recalled for further cross-examination, the court refused to allow counsel to question him based on the notes.
Welkie also had written to his girlfriend, Judith Barlow, prior to his being released on bail. The government called Barlow as a witness, *270and Stillman subpoenaed Welkie’s letters to her. The Court perceived the subpoena as invading Barlow’s privacy, examined the letters in camera, and then permitted counsel to see only two small segments of the letters, quashing Stillman’s subpoena as to the balance.
Welkie stated that during the period about which he was testifying, he was a heavy user of heroin and also used angel dust. Stillman’s expert testified that the use of these drugs could impair perception and memory and that angel dust could cause major perceptual distortions. Stillman then moved to have Welkie examined by any qualified person concerning the effect of these drugs on his memory and perception. The court apparently misperceived the thrust of Stillman’s argument and denied the motion as one that questioned Welkie’s competence as a witness.
. As Judge Weinstein remarks:
To the extent possible, the admissibility of coconspirators’ statements should be discussed at the pre-trial conference, or if at trial, outside the hearing of the jury. At times, the court will be able to make its determination on the basis of proffers or even on the opening or what it knows of the *271available proof from the pretrial or suppression hearings.
... [I]n most cases the judge can determine from colloquy, documents marked in advance of trial, suppression hearings and oné or two witnesses whether there is sufficient evidence to warrant admission of a co-conspirator’s statement.
1 Weinstein & Berger, supra, ¶ 104[5], at 104-51 to -52 (footnote omitted).