JUSTICE O'CONNOR, with whom JUSTICE BRENNAN and JUSTICE BLACKMUN join, concurring in the judgment.
I agree with the Court that the convictions obtained in the trial court against defendants Mechanik and Lill should not have been set aside. I write separately because I believe that the analysis adopted by the Court for determining the effect of a violation of the rules governing the conduct of grand juries effectively renders those rules a dead letter, thereby seriously undermining the grand jury's traditional function of protecting the innocent from unwarranted public accusation.
The grand jury has two principal functions. First, it bears the weighty responsibility of investigating crime and determining whether there is probable cause to believe that a crime has been committed. United States v. Calandra, 414 U.S. 338, 414 U. S. 343 (1974). The second, and no less important, task of the grand jury is to
serv[e] the invaluable function in our society of standing between the accuser and the accused, whether the latter be an individual, minority group, or other, to determine whether a charge is founded upon reason or dictated by an intimidating power or by malice and personal ill will.
Wood v. Georgia, 370 U. S. 375, 370 U. S. 390 (1962). To further the grand jury's investigative function, the grand jury traditionally has been given "wide latitude" in its inquiries. Calandra, supra, at 414 U. S. 343. See also United States v. Dionisio, 410 U. S. 1, 410 U. S. 17 -18 (1973). Prosecutors have been accorded similar leeway in presenting their cases to the grand jury, see, e.g., United States v. Adamo, 742 F.2d 927, 936-938 (CA6 1984), cert. denied, 469 U.S. 1193 (1985), but they are bound by a few, clear rules which were carefully drafted and approved by this Court and by Congress to ensure the integrity of the grand jury's functions.
Federal Rule of Criminal Procedure 6(d) is one such rule; it is designed to guard the secrecy of the grand jury proceedings, prevent intimidation of jurors, and guarantee that the grand jury is given the opportunity to make an independent examination of the evidence and render its probable cause and charging determinations free of undue prosecutorial influence. See, e.g., United States v. Echols, 542 F.2d 948, 951 (CA5 1976), cert. denied, 431 U.S. 904 (1977); United States v. Lill, 511 F.Supp. 50, 55-57 (SD W.Va.1980); 1 C. Wright, Federal Practice & Procedure § 105, p. 237, and n. 1 (2d ed.1982). For example, if the Government, in violation of Rule 6(d), were to have all witnesses remain in the courtroom while the grand jury investigation was going on to ensure that all testified in a consistent manner, it cannot seriously be doubted that this practice would hinder the grand jury in its task of uncovering the truth. Similarly, if the prosecuting attorney were to remain in the jury room during the jury's deliberations in contravention of the Rule, a very real possibility would arise that the jury's deliberations or vote would be unduly influenced by the prosecutor's presence.
The Federal Rules clearly envision that dismissal of the indictment may be an appropriate remedy for such violations of Rule 6(d). See, e.g., Fed.Rule Crim.Proc. 12(b)(2). Indeed, courts have consistently employed the remedy of dismissal of the indictment for deviations from Rule 6(d) which may imperil the grand jury's independence. See, e.g., Lill, supra, at 58 (collecting federal cases). See also Nadel, Presence of Unauthorized Persons During State Grand Jury Proceedings as Affecting Indictment, 23 A.L.R. 4th 397 (1983) (hereinafter Nadel) (collecting state cases dealing with similar violations of state rules). To be sure, a violation must be clearly established before dismissal may be contemplated. The grand jury proceeding is accorded a presumption of regularity, which generally may be dispelled only upon particularized proof of irregularities in the grand jury process. See, e.g., United States v. Johnson, 319 U. S. 503, 319 U. S. 512 -513 (1943). And not every violation of Rule 6(d) will create such a likelihood of prejudice as to warrant the drastic remedy of dismissal. The Federal Rules dictate that dismissal is appropriate only when a violation has impaired the substantial rights of the accused. See Fed.Rule Crim.Proc. 52.
Rule 52(a) provides that its harmless error inquiry extends to "[a]ny error, defect, irregularity or variance." The Advisory Committee's notes to Rule 52 state that "[t]his rule is a restatement of existing law," which specifically provided for a harmless error analysis of objections going to the validity of the indictment in 18 U.S.C. § 556 (1946 ed.). See 18 U.S.C.App. p. 657. The language of Rule 6 does not exempt the Rule from a harmless error scrutiny. In fact, the commentary accompanying it states that the Rule "generally continues existing law" and expressly refers to the harmless error rule of 18 U.S.C. § 556 (1946 ed.), thereby confirming the rulemakers' intent that violations of Rule 6(d) would be among those errors subject to harmless error review. See Advisory Committee's Notes on Fed.Rule Crim.Proc. 6(d), 18 U.S.C.App. p. 568.
A Rule 6(d) violation is one affecting the grand jury proceeding, and is not in any sense a trial error. Accordingly, the logical focus of the harmless error inquiry is an examination of the influence of the error on the charging decision. Indeed, in most Rule 6(d) cases, a court conducting a harmless error inquiry will of necessity focus on the effect of the alleged error on the grand jury's charging decision, rather than the verdict, because the rules governing the disclosure of grand jury materials to defendants and the waiver provision of Rule 12(f) virtually ensure that all claims of violations of Rule 6(d) will be made before or during trial. See, e.g., 18 U.S.C. § 3500; Fed.Rules Crim.Proc. 6(e)(3)(C)(i), (ii); Dennis v. United States, 384 U. S. 855, 384 U. S. 868 -875 (1966); 8 J. Moore, Federal Practice 6.05[3] (2d ed.1985) (discussing defendants' access to grand jury materials under the above cited authorities). See also Lill, supra, at 58, 61 (most reported Rule 6(d) claims raised and disposed of before trial).
In my view, when, as in these cases, a court decides to reserve the ruling on a timely raised and diligently pursued motion to dismiss based on an alleged violation of Rule 6(d) until after a verdict is returned, the focus of the court's inquiry should remain on the grand jury's charging decision. Yet the Court shifts the focus of the harmless error analysis in such circumstances from an examination of the violation's effect on the indictment to an assessment of the violation's effect on the trial verdict, without regard to the timing of the defendants' objection. See ante at 475 U. S. 70 -71. The Court then concludes that a conviction automatically renders harmless any violation of Rule 6(d). This holding is not justified by the applicable rules, nor can it be reconciled with precedent.
A number of federal courts have employed a rule directly in conflict with that adopted by the Court: they presume the existence of prejudice from the presence of unauthorized persons in the grand jury room, and apply a rule of automatic dismissal of the tainted indictment. See, e.g., United States v. Fulmer, 722 F.2d 1192, 1195, n. 5 (CA5 1983); Echols, 542 F.2d at 951; Latham v. United States, 226 F. 420 (CA5 1915); Lill, 511 F.Supp. at 58 (collecting lower federal cases). See also Nadel § 4 (collecting state cases); 2 W. LaFave & J. Israel, Criminal Procedure § 15.6 (1984). Other courts have applied a harmless error test to Rule 6(d) violations, but have uniformly evaluated the prejudice to the defendant by looking to the violation's likely effect on the grand jury's deliberations, not merely to its significance in light of the trial verdict. See, e.g., United States v. Condo, 741 F.2d 238, 239 (CA9 1984) (per curiam), cert. denied, 469 U.S. 1164 (1985); United States v. Computer Sciences Corp., 689 F.2d 1181, 1185-1186 (CA4 1982), cert. denied, 459 U.S. 1105 (1983); United States v. Kahan & Lessin Co., 695 F.2d 1122, 1124 (CA9 1982) (per curiam); United States v. Rath, 406 F.2d 757, (CA6), cert. denied, 394 U.S. 920 (1969). I have found no Rule 6(d) cases in which a per se rule based on the ultimate verdict at trial has been applied. Cf. also United States v. Lane, 474 U. S. 438, 474 U. S. 447 -448 (1986) (disapproving use of per se rules in harmless error analysis).
The Court's focus on the effect of the verdict, in combination with its per se rule, gives judges and prosecutors a powerful incentive to delay consideration of motions to dismiss based on an alleged defect in the indictment until the jury has spoken. If the jury convicts, the motion is denied; if the jury acquits, the matter is mooted. The Court's approach thus undermines the authority of Rule 6(d), exposes to the ordeal of trial any defendants who would otherwise have a right to dismissal of the indictment, and undermines adherence to the very measures that this Court proposed and Congress implemented to guarantee that the grand jury is able to perform properly its screening function.
In my view, when a defendant makes a timely objection to the grand jury indictment based on a violation of Rule 6(d), the remedy of dismissal of the indictment is appropriate if it is established that the violation substantially influenced the grand jury's decision to indict, or if there is grave doubt as to whether it had such effect. See Lane, supra, at 474 U. S. 449 ; Kotteakos v. United States, 328 U. S. 750, 328 U. S. 765 (1946). The focus of the prejudice inquiry should be on the effect of the alleged error on the grand jury's decision to indict, even if the court postpones its decision until the conclusion of the trial.
This approach would not impose unwarranted costs on the criminal justice system. The prosecution has it within its power to avoid dismissals by adhering to the simple dictates of Rule 6(d), and to remedy any violation of the Rule by obtaining a superseding indictment so as to avoid the risks of subsequent dismissals. Even where an unremedied violation is proved, the trial judge must still be satisfied that the violation resulted in grand jury intimidation or improper influence on important witnesses' testimony, and thus had a "substantial influence" on the indictment returned, or that there is grave doubt as to whether it had such effect. Kotteakos, supra, at 328 U. S. 765. See also Lane, supra, at 474 U. S. 449.
In these cases, the District Court found, after a scrupulous examination of the record, that the violation was harmless, a finding which was not found wanting on appeal. The District Court preliminarily observed:
It is especially significant to note that the two indictments were returned by the same grand jury. The court's review of the attendance and voting records of that grand jury reveals that each of these indictments was returned by a unanimous vote. A nucleus of the same seventeen grand jurors voted for each indictment. In addition, one other grand juror voted for the first indictment but did not vote on the second, while two others voted for the second indictment but did not vote on the first.
511 F.Supp. at 58-59.
Both agents had testified separately before the same grand jury in support of the first, untainted indictment, giving the jury ample opportunity to weigh the credibility of each agent prior to their joint appearance. Moreover, both agents had access to all grand jury materials in the case pursuant to Rule 6(e)(3)(A)(ii), and thus the likelihood that their joint testimony created a potential for collusion not already available is minute.
Turning to an examination of the indictment itself, the District Court found that the substantive counts of which the defendants were convicted were "identical or virtually so" to the counts returned in the superseded indictment, and that those counts had "a probable cause basis entirely independent of the testimony presented to the grand jury after the return of the [superseded] first indictment." Id. at 59. It concluded that, as to the substantive counts, "there was neither prejudice nor potential for prejudice." Ibid. Thus, the only count upon which the defendants could have been prejudiced by the objectionable joint testimony of the Drug Enforcement Administration agents was the conspiracy count.
Although the District Court conducted its post-trial harmless error review in part with an eye to the effect of the error on the verdicts, its findings also make clear that the effect of the joint testimony on the grand jury's decision to indict on the conspiracy count was negligible. The District Court carefully isolated the alterations and additions to that count which were the subject of the joint testimony. After examining the testimony given by other grand jury witnesses, the trial judge concluded that
the grand jury would, in my view, undoubtedly have returned the very same second indictment even had [the] Agents… testified separately.
Id. at 61. Accordingly, I would reverse the judgment of the Court of Appeals insofar as it set aside the defendants' conspiracy convictions and affirm the Court of Appeals' judgment regarding the defendants' cross-petitions.