dissenting.
Under 18 U.S.C. § 3432, the prosecution was obliged to give Donnell Young a complete witness list at least three days before voir dire began, so that Young — a man faced with the penalty of execution — could avoid “trial by ambush.” United States v. Fulks, 454 F.3d 410, 422 (4th Cir.2006). Yet, through what the district court found to be negligence, the prosecution failed to comply with this simple, but plainly mandatory directive. The question we face on appeal is whether the district court, the very same court that has presided over this vast, complex drug conspiracy since 1998 and accepted the guilty pleas of multiple other co-conspirators, committed a clear error of judgment in finding that the prosecution did not exercise reasonable diligence in producing nineteen after-dis*467covered witnesses. Because I believe the answer is no, I respectfully dissent.
I.
First, I take issue with the majority’s view that a district court may abuse its discretion when it decides to remedy a violation of § 3432 by excluding after-discovered witnesses from testifying at trial. Section 3432 provides, in no uncertain terms, that: “A person charged with treason or other capital offense shall at least three days before the commencement of trial be furnished with a copy ... of the witnesses to be produced on the trial for proving the indictment....” 18 U.S.C. § 3432. Despite this clear language, the majority would find that witnesses not disclosed in the pretrial notice must be allowed to testify at trial, so long as the prosecution demonstrates good faith and reasonable diligence, and if the defendant cannot demonstrate “irreparable prejudice.” Maj. Op. at 466.
But Congress has amended § 3432 twice, once in 1948 and again in 1994, and the text of the statute still provides for only one exception to this notice requirement: when listing the witness’s name would “jeopardize the life or safety of any person.” 18 U.S.C. § 3432. And as the Supreme Court recognized over a century ago, “[t]he words of the existing statute are too plain to be misunderstood.... The provision is not directory only, but mandatory to the government; and its purpose is to inform the defendant of the testimony which he will have to meet, and to enable him to prepare his defense.” Logan v. United States, 144 U.S. 263, 304, 12 S.Ct. 617, 36 L.Ed. 429 (1892).
True, the statute does not state, in explicit terms, that after-discovered witnesses must be excluded from testifying at trial. And I recognize that many courts have established special circumstances for when a district court may, in its discretion, allow witness testimony despite the prosecution’s non-compliance with § 3432. See, e.g., Fulks, 454 F.3d at 424; but see id. at 438-41 (Williams, J., concurring) (finding that the statute precludes any judicially created exceptions). But the majority goes farther by requiring “courts [] to balance [a defendant’s interest in avoiding trial by surprise] with the equally valid public interest in courts’ truth-seeking function,” Maj. Op. at 462, which assumes the burden should be shared equally between the parties.
The problem is that “Congress’s concern in passing [§ 3432] was with allowing defendants facing possible sentences of death sufficiently to prepare their defense, regardless of whether the statute precluded the Government from introducing some relevant testimony.” Fulks, 454 F.3d at 439. Indeed, in Logan, the only case in which the Supreme Court has spoken as to the scope of this statute, the Court found that “particular witnesses, afterwards coming to the knowledge of the government, ... might be permitted on special reasons shown, and at the discretion of the court, to testify in the case.” Logan, 144 U.S. at 306, 12 S.Ct. 617 (emphasis added). And in Fulks, upon which the majority so heavily relies, the Fourth Circuit described § 3432 as “imposing] no per se bar against testimony from witnesses discovered after the prosecution’s witness list is due,” 454 F.3d at 423, but concluded that such witnesses “should only be permitted to testify ... when the prosecution has demonstrated that its failure to include the witnesses on the list was in good faith and not the result of a lack of diligent investigation,” id. at 424 (emphasis added). “Even then,” the court noted, “if the defendant can demonstrate actual prejudice ..., the trial court should preclude the witness from testifying unless a brief adjournment *468of the trial would cure the prejudice.” Id. (emphasis added).
Therefore, I believe the proper approach is to assume the following: (1) that after-discovered witnesses may be admitted only in a narrow, rare set of cases, and (2) that the decision to do so is left to the discretion of the trial court. In other words, there should be no “balancing test,” nor should the burden be shared equally between the parties; courts should presume that the after-discovered witnesses are not allowed unless the government shows by clear and convincing evidence that it acted in good faith and that it exercised reasonable diligence in its investigation. Fulks, 454 F.3d at 424. Even then, the discretion to apply such an exemption lies solely within the province of the trial courts. Logan, 144 U.S. at 306, 12 S.Ct. 617. Such an approach accords trial courts their due deference, but also recognizes that “Section 3432 is not a forgiving statute,” United States v. Fernandez, 172 F.Supp.2d 1265, 1280 (C.D.Cal.2001), and gives full effect to the statute’s intended purpose: “to inform the defendant of the testimony which he will have to meet, and to enable him to prepare his defense,” Logan, 144 U.S. at 304, 12 S.Ct. 617.
The result of the majority’s contrary position — that the remedy must balance equally the rights of both the capital defendant and the government — is that a district court now must allow previously undisclosed witnesses to testify at trial if it decides that the government’s interest in providing the testimony somehow outweighs the defendant’s interest in excluding it.1 But this interpretation waters down the protection afforded by § 3432 by merely applying to capital cases the discovery standards accorded to non-capital cases. Under the Federal Rules of Criminal Procedure, a trial court may impose a number of sanctions on the prosecution for failing to meet its discovery obligations, including the granting of a continuance, the exclusion of the undisclosed evidence, or the granting any other remedy “that is just under the circumstances.” Fed. R.Crim.P. 16(d)(2). In considering whether suppression of evidence is an appropriate remedy, the court is to balance a number of factors: “(1) the reasons for the government’s delay in producing the materials, including whether it acted intentionally or in bad faith; (2) the degree of prejudice, if any, to the defendant; and (3) *469whether the prejudice to the defendant can be cured with a less severe course of action, such as granting a continuance or a recess.” United States v. Maples, 60 F.3d 244, 247 (6th Cir.1995). These factors, no doubt, sound strikingly familiar to the ones adopted by the majority. But I do not believe Congress meant for courts of appeals to balance a multitude of judicially created factors — the same factors used in non-capital cases — to determine whether a district court committed a clear error of judgment in following the plain language of a statute intended to give capital defendants heightened discovery protection.
II.
I also disagree with the majority’s holding that the district court abused its discretion in finding that the prosecution failed to exercise reasonable diligence in its investigation. The prosecution provided its first witness list to Young on October 9, 2005, identifying one hundred and fifty-one individuals to be called to testify. Over the next two days, the prosecution provided the names of fifteen additional witnesses, for a grand total of one hundred and sixty-six witnesses. Then, twenty days later, and after the start of voir dire, the prosecution attempted to provide the names, but no addresses, for an additional nineteen witnesses, most of whom were identified as a result of an apparent eleventh-hour interview of Cornelius Humphrey.
Notwithstanding the prosecution’s assertion that “it could not have known about this incident or the witnesses before the interview,” the district court found the prosecution’s claim to be “not credible.” As an initial matter, it bears noting the obvious: that the district court is in “the best position to evaluate a party’s pre-trial diligence,” Fulks, 454 F.3d at 424, which applies with particular force to the instant case. See also Gen. Elec. Co. v. Joiner, 522 U.S. 136, 142, 118 S.Ct. 512, 139 L.Ed.2d 508 (1997) (“ ‘[Cjases arise where it is very much a matter of discretion with the court whether to receive or exclude the evidence; but the appellate court will not reverse in such a case, unless the ruling is manifestly erroneous.’ ”) (quoting Spring Co. v. Edgar, 99 U.S. 645, 658, 25 L.Ed. 487 (1878)).
What is most surprising, or perhaps disturbing, is the majority’s willingness to substitute its view of “reasonably diligent” for that of the district court’s. The same court has presided over the entire conspiracy since 1998, has accepted the guilty pleas of many other co-conspirators, and no doubt has intimate knowledge of the ongoing investigation. According the proper level of deference, I believe that the exclusion of Mary Walker and the eighteen other after-discovered witnesses was proper, and that the complexity of the investigation offers no recourse to the Government.
Mary Walker. The prosecution’s failure over a span of seven years to conduct follow-up interviews of the bystanders to the murder, many of whom knew the existence of Mary Walker, displays a lack of reasonable diligence. The two witnesses who identified Walker after the start of voir dire, Mary Judy and Dianne Jenkins, both resided in Oklahoma City near the drug house itself and were known and available to federal investigators. But, for some reason, in the seven years since the filing of the indictment in federal court, the prosecution never interviewed the bystanders or neighbors near the murder scene, choosing instead to rely upon interviews conducted by the Oklahoma City Police Department immediately after the murder. I have my doubts as to whether this is standard investigative procedure. Regardless, it is certainly reasonable for *470us to believe that a diligent investigation would have produced Walker at some point prior to the eve of trial.
True, the district court’s order focused on the eighteen witnesses discovered from Humphrey, and did not specifically explain how the prosecution’s efforts to discover Walker fell short. But I disagree with the majority that this in and of itself warrants reversal. For one, the exact same reasons that the district court gave for excluding the other eighteen witnesses apply equally to Walker — namely, that the case had been pending for over seven years, that the prosecution had “ample opportunity” to interview the witnesses prior to trial, that there was no evidence that the witnesses were uncooperative, and that all the evidence points to the fact that the prosecution simply did not “thoroughly interview” the witnesses. For another, as I have already explained, a district court need not articulate its reasons for complying with a statutory mandate. And the cases that the majority cites, Fulks and Gregory, do not counsel a different result. Those courts considered whether the district court abused its discretion by refusing to apply § 3432, while here, we consider whether the district court abused its discretion by applying § 3432. It is one thing for us to hold that a district court’s failure to comply with a statute is a reversible error, but it is quite another for us to hold that a district court’s failure to explain why it complied with a congressional mandate constitutes an abuse of discretion.
The Other Eighteen After-Discovered, Witnesses. The prosecution’s failure over a span of seven years to interrogate fully Humphrey as to his knowledge of Young’s reputation and prior bad acts displays a lack of reasonable diligence. According to the prosecution’s theory, Humphrey is the most important witness linking Young to the murder and drug conspiracy because he was present at the crime scene. Indeed, federal authorities initially charged Humphrey with the murder of Woody Pil-cher. For the last decade, Humphrey repeatedly cooperated with authorities while incarcerated in Oklahoma City and while living in Los Angeles, both focal points of the investigation. Now, after five separate interviews by local and federal authorities, the prosecution claims that Humphrey simply failed to reveal the assault on Troy Rogers until his pretrial interview on October 19, 2005.
One view of the foregoing is to take the prosecution at its word: that Humphrey, a central witness who has been available to the prosecution since 1998, and with no evidence of prior uncooperative behavior, failed to provide all the information he knew. Another view is that the prosecution simply failed to interrogate Humphrey adequately. Whether or not we would conclude, on a clean slate, that the prosecution’s claim was the more credible one, it is not a clear error of judgment to believe that a diligent investigation should have exposed this particular incident sometime before the start of trial.
Complexity. The majority has not explained the relevance of the scope and complexity of the underlying investigation. While this case admittedly involves multiple suspects, crimes, murders, and victims, the focus of the inquiry should be on only one target: Young. Whether the prosecution has spread its resources too thin should not be a means to excuse the requirement that it be diligent in its investigation toward the defendant. Keeping in mind that “Section 3432 is not a forgiving statute,” Fernandez, 172 F.Supp.2d at 1280, and the societal interest in giving defendants the greatest degree of protection when their life is at stake, the district court did not abuse its discretion in con-*471eluding that the prosecution failed its statutory obligations.2
Finally, because I take the view that the district court may exclude an after-discovered witness at trial if the government fails to demonstrate reasonable diligence, it is unnecessary to consider whether Young suffered prejudice, or whether a continuance would have been a more appropriate remedy. See Fulks, 454 F.3d at 423 (requiring showing of diligence and good faith before permitting presentation of after-discovered witness); Fernandez, 172 F.Supp.2d at 1280. I only note that, contrary to the Government’s position, in the century since Logan, the Supreme Court has declined to circumscribe a trial court’s discretion in proscribing the remedy for a § 3432 violation. Indeed, there does not appear to be any persuasive judicial authority for the proposition that a continuance is the exclusive option. See generally Taylor v. Illinois, 484 U.S. 400, 414, 108 S.Ct. 646, 98 L.Ed.2d 798 (1988) (holding that the compulsory process clause of the Sixth Amendment permits exclusion of testimony of a defense witness as a sanction for violating a discovery rule because it was “reasonable to presume that there is something suspect about a defense witness who is not identified until after the 11th hour has passed”); Boardman v. Nat’l Med. Enter., 106 F.3d 840, 843 (8th Cir.1997) (“The power of the trial court to exclude exhibits and witnesses not disclosed in compliance with its discovery and pretrial orders is essential to the judge’s control over the case.”) (citation and internal quotations omitted); Conway v. Chem. Leaman Tank Lines, Inc., 687 F.2d 108, 112 (5th Cir.1982) (While continuances are “generally more appropriate remedy than exclusion of evidence,” “[t]he granting or denial of a continuance ... is a procedural matter of the kind that this Court has repeatedly said is subject to the discretion of the trial judge.”).
III.
Because I would affirm the district court’s decision to exclude the after-discovered witnesses, I will address briefly the Government’s contention that § 3432 does not apply to witnesses called only to establish non-statutory aggravating factors— specifically, those intended to testify about the torture of Rogers.3
Section 3432, by its terms, applies to witnesses to be called “for proving the indictment,” 18 U.S.C. § 3432, and most courts have found that non-statutory aggravating factors do not need to be alleged in an indictment. See United States v. Brown, 441 F.3d 1330, 1368 (11th Cir.2006) (collecting cases). Nonetheless, I do not believe that § 3432 is inapplicable to the witnesses in this case. Young is charged with using a firearm to kill Pilcher in furtherance of a continuing criminal enterprise and with the goal to eliminate Pilcher as a potential witness. The Government admits that the evidence relating to the torture of Rogers “demonstrates [Young’s] role as an enforcer ... [and] helps refute his claim of duress as a defense.... ” (Appellant’s Br. 59 n. 16.) Accordingly, because the testimony elicited from these eighteen after-discovered witnesses would *472be used not only to prove non-statutory aggravating factors, but also to prove the crimes alleged in the indictment, the full scope of § 3432 should apply.
And to the extent that the Government now asks us to allow witnesses called to testify about non-statutory aggravating factors, we should also be forced to recognize that the language of § 3432 is mandatory. The statute is no more silent on its application to non-statutory aggravating factors than it is silent on the question of whether after-discovered witnesses may be admissible based on good faith and diligence on the part of the Government. If the statute is, in fact, “too plain to be misunderstood,” Logan, 144 U.S. at 304, 12 S.Ct. 617, then the proper approach would be to reject judicially created exemptions for good faith, diligence, and prejudice, and exclude after-discovered witnesses regardless of whether the result would be to preclude the Government from introducing relevant evidence.
IV.
For those reasons, I respectfully dissent.
. I should note that we are the first court of appeals since the statute's enactment by the First Congress in 1790 to reverse a district court's decision to remedy a clear violation of § 3432 with the exclusion of after-discovered witnesses. Many cases hold that a district court does not abuse its discretion when it decides to allow witness testimony despite non-compliance with § 3432. See, e.g., Fulks, 454 F.3d at 424-27 (affirming district court’s decision to admit witnesses on narrow grounds); United States v. Chandler, 996 F.2d 1073, 1099 (11th Cir.1993) (affirming a district court's decision to admit a police officer's testimony); United States v. Greene, 497 F.2d 1068, 1082 (7th Cir.1974) (affirming a district court's decision to admit expert witness testimony). Many other cases hold that failure to comply with § 3432 constitutes reversible error. See, e.g., United States v. Cro-well, 442 F.2d 346, 347-48 (5th Cir.1971) (“Section 3432 is mandatory, and a defendant indicted for a capital offense must be given the benefits of its provisions, ... and the failure to allow defendant its benefits would be plain error.”); Hall v. United States, 410 F.2d 653, 660 (4th Cir.1969) (stating that failure to comply with § 3432 is reversible error); Amsler v. United States, 381 F.2d 37, 45 (9th Cir.1967) (reversing district court's decision to admit witnesses in violation of § 3432); Fernandez, 172 F.Supp.2d at 1280 (stating that "Section 3432 is not a forgiving statute,” and that it "does not excuse sloppiness or negligence on the part of the government,” and excluding the witnesses’ testimony). To my knowledge, no case holds that a district court abuses its discretion by remedying a violation of § 3432 with the exclusion of after-discovered witnesses.
. Moreover, the district court was more lenient than it could have been. Although some courts have held three days notice to be sufficient, other courts have required greater notice. See, e.g., United States v. Tipton, 90 F.3d 861, 889 (4th Cir.1996) (district court requiring witness list ten days in advance of trial date).
. Even if the Government’s argument is correct, it would only allow testimony of the eighteen after-discovered witnesses testifying about the alleged torture of Rogers. The eyewitness testimony of Walker would still be excluded.