COOK, J., delivered the opinion of the court, in which MILLS, D.J., joined. COLE, J. (pp. 466-72), delivered a separate dissenting opinion.
OPINION
After voir dire began in Donnell Young’s capital murder case, the government located nineteen new witnesses and sought to add those names to the list of more than 100 already provided to the defense. One of the nineteen, a new eyewitness who saw Young leaving the murder scene, came to light through trial preparation interviews of crime-scene bystanders. Another trial preparation interview turned up information about a related violent assault .Young committed. Through pursuit of that lead, the government located the other eighteen individuals as persons having knowledge of that assault.
When Young objected to the introduction of any evidence from the nineteen witnesses, the district court sua sponte invoked 18 U.S.C. § 3432, which requires the government to provide a capital defendant with a witness list at least three days before the start of trial, as grounds for excluding the witnesses. We find an abuse of discretion in the court’s choice to exclude relevant testimony on the ground that the government failed to conduct a reasonably diligent investigation. We therefore vacate the district court’s order and remand for proceedings consistent with this opinion.
I.
A. Procedural Background
A seven-year federal investigation targeting the Los Angeles-based Rollin’ 90s Crips street gang in connection with a nationwide drug-distribution conspiracy and widespread acts of violence resulted in federal charges of murder, drug trafficking, money laundering, and firearm possession, as well as others, against more than twenty-five defendants. After a grand jury indicted Crips-member Donnell Young, a/k/a “Lil’ Peso,” on a drug-conspiracy charge, the government transferred him from an Oklahoma City jail, where he was being held in connection with the murder of Woody Pilcher, to the Middle District of Tennessee. The Fifth Superseding Indictment charges Young with numerous drug and weapons offenses and three counts related to Pilcher’s death — (1) killing Pilcher in furtherance of a continuing criminal enterprise and drug conspiracy, 21 U.S.C. § 848(e)(1)(A); (2) *457killing Pilcher to eliminate a potential witness, 18 U.S.C. § 1512(a)(1); and (3) causing Pilcher’s death by the use and carrying of a firearm during and in relation to a crime of violence or a drug-trafficking crime, id. § 924(e)(1), (j). The government seeks the death penalty.
The district court severed Young’s trial from other defendants’ and granted his motion to empanel two juries (the first selected for the guilt phase and the second selected for the potential sentencing phase). United States v. Young, 376 F.Supp.2d 787, 800 (M.D.Tenn.2005). After we vacated the district court’s bifurcated-jury decision, United States v. Young, 424 F.3d 499 (6th Cir.2005), jury selection began on October 24, 2005. When the government supplemented its pretrial witness list, Young moved to “preclude the new witnesses.” On January 6 and 27, 2006, the district court ordered the newly discovered witnesses excluded.1 On February 2, 2006 (three-and-a-half months later), voir dire ended. This interlocutory appeal prompted the court to postpone final jury selection. 18 U.S.C. § 3731.
Though the appellate issue concerns the district court’s choice of remedy for the government’s late-noticed witnesses, we first discuss the government’s proposed proof as background that informed the district court’s exercise of discretion. In presenting its case-in-chief, the government planned to link Pilcher’s murder to Young’s involvement in the Rollin’ 90s Crips drug-distribution conspiracy and his enforcer role therein by showing that, in addition to killing Pilcher, Young used violence to collect drug debts, including restraining Lawrence Washington and burning him with a butter knife, dismembering Wallace Davis’s dog, and beating and sodomizing Troy Rogers. According to the government, one of the newly discovered witnesses, Mary Roschelle Walker, can testify to seeing Young leave the murder scene. The other eighteen new witnesses can provide evidence relating to the assault on Rogers. The district court understood that, through this new evidence, the government hoped to bolster its proof of Young’s involvement in the drug-distribution conspiracy and Pilcher’s death, rebut any claim of duress, and establish as a non-statutory aggravating factor Young’s future dangerousness.
B. The Pilcher Homicide
The government alerted the district court that it planned to introduce the following evidence at trial: Young (1) anticipated receiving either a kilogram of cocaine or $20,000 for killing Pilcher, (2) went to an Oklahoma City drug house run by Wallace Davis for that purpose, and (3) killed Pilcher by tying him up, stabbing him, and shooting him. Government’s Br. at 7.
Cornelius Humphrey, Coy Baird, and Lawrence Washington were present at the shooting. After the shooting, police questioned numerous bystanders who reported hearing gunshots and seeing two people (later identified as Humphrey and Baird) leave the scene. Police arrested Humphrey and Baird, who both then identified Young as the shooter. Humphrey and Baird are now government witnesses. Federal officials did not independently question the bystanders during their later investigation, however, thinking that, because none had reported seeing Young leave the scene, their testimony would only *458provide context for Humphrey’s and Baird’s more specific recollections.
A few weeks later, police arrested Young in Los Angeles on an Oklahoma murder warrant. While in state custody, he allegedly confessed to another inmate that he killed Pilcher, and also that he had previously tortured Lawrence Washington by burning him with a butter knife and dismembered Wallace Davis’s dog to collect on a drug debt. A grand jury eventually indicted Young on the federal charges, and the government transferred him to the Middle District of Tennessee.
C. The Discovery of Mary Roschelle Walker
On October 9, 2005, the prosecution, as required by 18 U.S.C. § 3432, provided Young with a list of the names and addresses of 151 potential trial witnesses. During final trial preparations, federal prosecutors and Los Angeles police detective George Leiker (who was heavily involved in the Rollin’ 90s investigation) traveled from Nashville to Oklahoma City to serve trial subpoenas and prepare the bystanders to testify. During these final interviews, two previously questioned bystanders disclosed information that pointed the government to a new eyewitness. On October 8, bystander Mary Judy said someone — perhaps named “Rosalyn” — told her that she saw the shooter flee the murder scene.2 Then, on October 18, bystander Dianne Jenkins said that someone told her “Rochelle” had seen the killer leave the crime scene. Jenkins said she knew Rochelle because she had previously helped her treat Lawrence Washington’s burns (after Young allegedly tortured him). Jenkins added that Rochelle was related to a “Richardson” family and had been married to “Walter Walker.” The next day, Jenkins identified a picture of Mary Roschelle Walker.
On October 28, the prosecutors and Leiker returned to Oklahoma City, found Mary Walker days later, and interviewed her. Confirming what Judy and Jenkins had said, Walker told them she was with her husband, Walter Walker,3 in a car on the day of the shooting when they heard gunshots and saw Young walking away from the house. She recognized Young because of their repeated contact at a drug house that Young paid her to clean. She also confirmed that she had helped treat Washington’s injuries. The next day, on October 31, the government provided Young with a supplemental witness list that included Mary Walker.
D. The Discovery of Troy Rogers and Seventeen Other Witnesses
Also during final trial preparation, the government met with Cornelius Humphrey to go over his testimony. By now — October 19, 2005 — Humphrey had been interviewed four previous times, had testified before the grand jury, and had been told to reveal everything he knew about the Rollin’ 90s Crips drug conspiracy. Nevertheless, at this fifth interview he disclosed for the first time that in Oklahoma City he had seen Young and others severely beat a man, known to him only as “Mr. T,” and sodomize him with a broom handle.
Armed with that new information, the government contacted local police, but no *459one at the department could identify Mr. T. When the prosecutors and Leiker returned to Oklahoma City on October 28, however, they reviewed police records showing that Troy Rogers, a/k/a Mr. T, reported being the victim of an assault and named “Lil’ Peso” as his assailant. The prosecution team found and interviewed Rogers the next day, and he confirmed that Young had severely beaten him for a drug debt. The prosecution located police photographs and hospital records documenting Rogers’s injuries, and, from the police file on Rogers’s assault, discovered seventeen new witnesses, including hospital staff.
The government’s October 31, 2005, supplemental list included Rogers and the other new witnesses, many of whom had not yet been located or interviewed. Soon thereafter, the government provided Young with relevant copies of police reports, photographs, hospital records, and notes that explained the origin of and purpose to be served by the additional witnesses.
E. Young’s Motion to Preclude the New Evidence
On November 4, 2005, Young moved to preclude evidence of Rogers’s assault, including the nineteen witnesses’ testimony (although Mary Walker does not represent an assault witness), and moved alternatively to adjourn jury selection to allow the defense time to investigate. This motion focused on the burden of investigating the new allegation, asserting that the late disclosure violated Young’s constitutional rights by compromising his ability to defend himself. Specifically, Young argued that the evidence to be introduced through the new witnesses would impermissibly amend the government’s death penalty notice, as the government would use this evidence as a non-statutory aggravating factor to justify a death sentence.
The next day the government responded, saying that the new evidence only represented direct evidence of the charged offenses. The death penalty notice filed, said the government, already included an allegation that Young committed acts of violence, including other violent acts as described in the Fifth Superseding Indictment. Because the Fifth Superseding Indictment alleged that Young and others committed violent acts including using and carrying firearms to collect drug debts and to assault, abduct, and kill other persons, the government argued that the new evidence did not amend, but rather supported, the existing allegations. As for the concern about investigating Rogers’s assault, the government argued to the court that the discovery it was providing to Young minimized the need for investigative methods different than those required for any other type of evidence. The response detailed the trial preparation interviews that unearthed the new evidence, and the government’s diligent pursuit of substantiation, as well as prompt transmittal of all relevant information to the defense (totaling thirty pages and including a typed report and notes from Rogers’s interview, photographs, police reports, and Rogers’s criminal record). The response also alerted the court to the government’s intent to transmit witness statements, witness addresses, and hospital records to Young.
The district court scheduled a hearing and asked the parties to argue the applicability of 18 U.S.C. § 3432, though neither party’s argument cited the statute, let alone argued its application. On January 6, 2006, the district court entered an order granting Young’s motion to exclude the nineteen witnesses’ testimony, reasoning that the government had violated § 3432 *460by not disclosing the supplemental witness list prior to the start of trial. The court noted that “[t]he purpose of this section is to enable a capital defendant to prepare to face the testimony against him.” JA 508. It then rejected the government’s argument that a trial does not begin until the jury is sworn, and held that “trial for purposes of § 3432 begins at the start of jury selection.” JA 509. The court found exclusion the proper remedy because “the rights of defendants in capital cases are important and to be protected,” and because the government was negligent in failing to interview Cornelius Humphrey more thoroughly at an earlier opportunity. JA 510-11.
The government moved for reconsideration and clarification, asking specifically whether it could call the nineteen excluded witnesses (1) in rebuttal or to rebut any claim of duress, (2) to establish a good-faith basis for cross-examination of witnesses, or (3) to establish non-statutory aggravating factors. On January 27, 2006, the district court denied reconsideration, but clarified its previous order by holding that (1) the excluded witnesses may appropriately be used in rebuttal, (2) it would determine at trial whether the Rogers assault may be referred to on cross-examination, and (3) only witnesses who were already on the October 9, 2005, witness list could testify to non-statutory aggravating factors. JA 547-48. Here again the court rested its ruling on the foundation that § 3432 was meant to “enable the Defendant to prepare to meet the evidence to be produced against him by the Government.” JA 548.
II.
A.Standard of Review
We review decisions regarding the exclusion of evidence for an abuse of discretion. E.g., United States v. Middleton, 246 F.3d 825, 838 (6th Cir.2001); United States v. Tocco, 200 F.3d 401, 414 (6th Cir.2000); United States v. Bonds, 12 F.3d 540, 554 (6th Cir.1993). And “any error of law in the district court’s application of § 3432 would constitute an abuse of discretion.” United States v. Fulks, 454 F.3d 410, 422 (4th Cir.2006); see also United States v. Heavrin, 330 F.3d 723, 727 (6th Cir.2003) (“An abuse of discretion occurs when the lower court relies on clearly erroneous findings of fact, or when it improperly applies the law or uses an erroneous legal standard.” (quoting United States v. True, 250 F.3d 410, 422 n. 2 (6th Cir.2001))). We give fresh review to questions of statutory interpretation. United States v. Morris, 203 F.3d 423, 424 (6th Cir.2000); see United States v. Martin, 378 F.3d 578, 580 (6th Cir.2004).
B.18 U.S.C. § 3432
Section 3432, originally enacted over 200 years ago and rarely cited in circuit cases since, provides that a capital defendant “shall at least three entire days before commencement of trial be furnished with a copy of ... a list of veniremen, and of the witnesses to be produced on the trial.”
C.Commencement of Trial
The government first asserts that the district court erred in concluding that the start of jury selection commenced trial for purposes of § 3432. Cf. Gomez v. United States, 490 U.S. 858, 872-73, 109 S.Ct. 2237, 104 L.Ed.2d 923 (1989) (indicating that a trial commences at different stages depending on the rights at stake). It relies on two nineteenth-century cases interpreting an earlier version of § 3432 and holding that “trial does not begin until the jury is completed and sworn.” United States v. Neverson, 12 D.C. (1 Mackey) 152 (D.C.1880); see also United States v. Curtis, 25 F. Cas. 726 (C.C.D.Mass.1826) (No. 14905) (same).
*461The district court disagreed, looking instead to United States v. O’Driscoll, 229 F.Supp.2d 370 (M.D.Pa.2002). In determining that trial for purposes of § 3432 begins when “potential jurors appear in court and are sworn,” the O’Driscoll court first tracked the provision’s history. Id. at 372-73. The court noted that both the Neverson and Curtis courts interpreted a version of § 3432 that required production of not only witnesses, but also “a list of the jury,” but that in 1948 Congress changed the term “jury” to “veniremen.” Id. at 372. The court found that change significant, observing that “[t]he purpose of providing a list of veniremen is to provide defense counsel an opportunity to prepare adequately for jury selection.” Id. at 373 (emphasis added). Stated differently, of what use would a list of potential jurors be after jury selection was complete? To shore up its conclusion that trial commences under § 3432 with jury selection, the court then identified four other provisions using language similar to “before commencement of trial,” and noted that courts construing that language elsewhere had also held that trial commences with jury selection. Id. at 373-74 (identifying Fed.R.Crim.P. 43; 21 U.S.C. § 851(a)(1); the Speedy Trial Act, 18 U.S.C. § 3161 et seq.; and the federal criminal removal statute, 28 U.S.C. § 1446(c)(1)).
The O’Driscoll court’s reasoning and the obvious importance of voir dire to litigants’ trial strategy persuades us to agree with the district court that, for purposes of § 3432, trial begins with the start of jury selection. The government’s October 31, 2005, supplemental witness list thus runs afoul of § 3432.
D. Factors Bearing on the Exclusion of After-Discovered Witnesses
1.
That said, the government argues that even if its supplemental list was not timely under § 3432, the district court’s exclusion of the witnesses constitutes an abuse of discretion. The statute itself is silent on whether the government may present the testimony of after-discovered witnesses, and this circuit has yet to wrestle with the remedial consequences of such a violation.
As a general matter, where a statute does not specifically provide for the exclusion of evidence in the event of a violation, federal courts disfavor exclusion as a judicially-fashioned remedy. See United States v. Abdi, 463 F.3d 547, 556 (6th Cir.2006) (“[T]here is no exclusionary rule generally applicable to statutory violations.” (collecting cases)). Sound policy supports its disfavor, and the Supreme Court has “repeatedly emphasized that the [exclusionary] rule’s ‘costly toll’ upon truth-seeking and law enforcement objectives presents a high obstacle for those urging application of the rule.” Pa. Bd. of Prob. & Parole v. Scott, 524 U.S. 357, 364-65, 118 S.Ct. 2014, 141 L.Ed.2d 344 (1998); see also Hudson v. Michigan, 547 U.S. 586, 591, 126 S.Ct. 2159, 165 L.Ed.2d 56 (2006) (“Suppression of evidence ... has always been our last resort, not our first impulse.”). Given exclusion’s high cost, federal courts invoke it only where its “ ‘remedial objectives are thought most efficaciously served.’ ” United States v. Leon, 468 U.S. 897, 908, 104 S.Ct. 3405, 82 L.Ed.2d 677 (1984) (quoting United States v. Calandra, 414 U.S. 338, 348, 94 S.Ct. 613, 38 L.Ed.2d 561 (1974)). “[D]e-ter[ring] constitutional violations” best serves exclusion’s remedial objectives. Sanchez-Llamas v. Oregon, 548 U.S. 331, 126 S.Ct. 2669, 2680, 165 L.Ed.2d 557 (2006) (noting a particular emphasis on Fourth Amendment violations). Indeed, the few suppression cases focused on statutory violations “implicated important *462Fourth and Fifth Amendment interests.” Id. at 2681.
Despite courts’ general aversion to exclusion, § 3432 declares capital trial procedure. See Logan v. United States, 144 U.S. 263, 303-04, 12 S.Ct. 617, 36 L.Ed. 429 (1892), abrogated on other grounds by Witherspoon v. Illinois, 391 U.S. 510, 523 n. 22, 88 S.Ct. 1770, 20 L.Ed.2d 776 (1968); cf. Murray v. Giarratano, 492 U.S. 1, 21 n. 9, 109 S.Ct. 2765, 106 L.Ed.2d 1 (1989) (Stevens, J., dissent ing) (collecting cases that recognize the need for heightened protections in capital cases); Ford v. Wainwright, 477 U.S. 399, 411, 106 S.Ct. 2595, 91 L.Ed.2d 335 (1986) (Marshall, J., plurality opinion) (“[DJeath is different.”). Section 3432 serves “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. In other words, it “is designed to prevent trial by ambush where a defendant’s life is at stake.” Fulks, 454 F.3d at 422. Given this weighty interest, as the Supreme Court explained over a century ago, the section “is not directory only, but mandatory to the government,” and “the trial cannot lawfully proceed until the requirement has been complied with.” Logan, 144 U.S. at 304, 12 S.Ct. 617. For this reason, appellate courts consistently hold that the government’s failure to provide a witness list to a capital defendant is reversible error. Fulks, 454 F.3d at 422 (collecting cases).
What is at stake here is an appropriate remedy for violation of the statute by supplementing a timely presented list with late-discovered witnesses. The ancient Logan Court first speculated about the possibility that “particular witnesses, af-terwards coming to the knowledge of the government, or becoming necessary by reason of unexpected developments at the trial, might be permitted, on special reasons shown, and at the discretion of the court, to testify in the case.” 144 U.S. at 306, 12 S.Ct. 617. And in Fulks, the Fourth Circuit thoroughly analyzed post-Logan case law and found that “virtually every court to have directly addressed the question of after-discovered witnesses has determined that § 3432 does not categorically preclude such witnesses from testifying at trial.” 454 F.3d at 423.4
With § 3432’s focus being protection of the capital defendant’s weighty interest in avoiding trial by surprise, courts look to balance that interest with the equally valid public interest in courts’ truth-seeking function. Distilling pertinent cases, Fulks identified three factors to be balanced by a trial court in deciding whether to exclude after-discovered-witness testimony: (1) the government’s good faith, id. at 423 (citing United States v. Rosenberg, 195 F.2d 583, 599-600 (2d Cir. 1952)); (2) the government’s diligence in pretrial investigations, id. (“[T]he prosecution may not present an after-discovered witness at trial if its failure to discover the witness prior to the expiration of the deadline established in § 3432 was due to a lack of reasonable diligence in conducting its pretrial investigation.”); and (3) any prejudice to the defendant caused by unfair surprise that could not be cured by brief adjournment, id. at 424.
*463The dissent disagrees with our balancing analysis here, but when the government fails to comply with § 3432, requiring the district court to fashion an appropriate remedy, this much is clear: the statute’s- purpose is “to inform the defendant of the testimony which he will have to meet, and to enable him to prepare his defense.” Id.; see also United States v. Greene, 497 F.2d 1068, 1082 (7th Cir.1974). Although “[sjection 3432 is not a forgiving statute,” and courts recognize it “does not excuse sloppiness,” United States v. Fernandez, 172 F.Supp.2d 1265, 1280 (C.D.Cal.2001), or bad-faith omissions, Fulks, 454 F.3d at 423, a sanction less severe than the disfavored remedy of exclusion will often provide a capital defendant with the full protection that § 3432 intended. Occasionally it may not, and our reading acknowledges that even absent prosecutorial abuses, “in certain situations, permitting a trial witness not included on the prosecution’s witness list to testify against the defendant will undermine [§ 3432’s] statutory purpose,” Fulks, 454 F.3d at 423-24. Such a district court decision would be reviewed for an abuse of discretion.
The dissenting view goes much further, fashioning a rule that after-discovered witnesses are presumed inadmissible unless the government establishes diligence and good faith, and “[e]ven then, the discretion to apply such an exemption lies solely within the province of trial courts.” Infra at 468. We agree that district courts exercise discretion over decisions regarding the admissibility of evidence. We do not agree, however, with the peculiar suggestion that a trial judge’s decision to exclude after-discovered witnesses on § 3432 grounds is somehow insulated from review, while its decision to admit such evidence is not.
2.
Against this backdrop, we return to the government’s argument that the district court abused its discretion in excluding the nineteen after-discovered witnesses. In its order, the district court did not find— and Young does not argue — that the government’s failure to include the nineteen after-discovered witnesses was in bad faith. The district court did, however, take issue with the government’s diligence.
Specifically, the court found that the government’s claim of best efforts was “not credible” because the case had been pending for six years, no evidence showed Humphrey was uncooperative, and the government could have done a more thorough job of questioning him in prior interviews. In the absence of a credible best-efforts defense, it decided the violation of the three-day notice warranted exclusion. JA 510. We do not read the court’s “not credible” observation as assessing credibility in the sense of truthfulness; rather, it appears to reflect the court’s rejection of the government’s claim that it could not have earlier discovered this evidence. With that viewpoint, the court labeled the government’s tardiness as “excusable negligence.” JA 510 (citing Fernandez, 172 F.Supp.2d at 1278).
Yet other cases analyze whether the government exercised reasonable diligence in conducting its investigation without tipping the scale with the benefit of hindsight. In Fulks, for example, the government learned during an interview with a witness scheduled to testify the next day that the defendant had, two years earlier, placed an incriminating phone call to the witness’s mother. 454 F.3d at 419. And this witness interview occurred nearly a month after voir dire ended and ten days after the prosecutor’s opening statement. Id. In affirming the district court’s decision to allow the new witnesses (the moth*464er and the agent who investigated the call), the Fulks court determined that the government should not be faulted for failing to interview the witness before trial. The court noted that the witness leading to the mother and agent was a minor figure who the government believed would provide only collateral testimony — that is, “the prosecution had no reason to believe that the [witness] had any useful information to offer.” Id. at 425. The impracticality of interviewing that witness, located a “considerable distance” from the court, also figured in the court’s judgment, as did the case’s complexity — “the crime spree spanned several states and touched over a hundred individuals the prosecution expected to call as witnesses.” Id.
In Gregory v. United States, 410 F.2d 1016 (D.C.Cir.1969), the government did not learn of a new witness until testimony at the defendant’s third trial for the same offense revealed a new person with relevant information. When the government sought to call the new witness, the court granted a continuance, after which the defense argued that it had inadequate time for a full investigation. Id. at 1019. The court found the government diligent in locating the new witness, despite the fact that the person revealing his name had “vaguely mentioned [the additional witness] ... at various times.” Id.
Discounting Gregory and Fulks, the district court here relied on a district court opinion that excluded evidence from two after-discovered witnesses. Fernandez, 172 F.Supp.2d at 1278. But Fernandez does not align well with this case because that prosecution team had the benefit of two leads that would have permitted timely disclosure. Although the court excused the failure to capitalize on the weaker lead, when combined with a subsequent lead from another witness who provided a “clear, detailed, unequivocal” statement with “many significant details,” the court found that the government failed to exercise reasonable diligence. Id.
3.
The facts here show the district court’s conclusion faulting the government’s diligence to be an abuse of discretion on three grounds. First, Young’s trial grew from a highly complex investigation. Second, rejection of Mary Walker’s testimony (on a subject different from the Rogers assault) went unexplained by the district court. Third, as regards the remaining eighteen witnesses who were to testify about the Rogers assault, the facts belie the district court’s stance on the government’s diligence here.
Complexity. The federal investigation here involved interviews of more than 200 individuals and coordination with law enforcement agencies in several states — circumstances even more complex than those recounted in Fulks. See Fulks, 454 F.3d at 425; see also JA 303 (stipulating to investigation’s massive scale).
Witness Mary Walker. This witness was to testify about seeing Young leave the murder scene, not about the assault on Rogers, yet the district court’s rationale for excluding the nineteen witnesses failed to separately account for these distinctions. The government’s proffering Mary Walker’s name on the supplemental list came about through circumstances wholly different from the other eighteen witnesses concerning the assault of Troy Rogers. Evaluation of the government’s diligence as to naming her outside the three-day deadline should have looked to whether the government’s reliance on police reports of bystander-interviews rather than face-to-face interviews was reasonable given (1) the considerable distance between Oklahoma City and Nashville (the trial venue), and (2) the expected minor role of *465these witnesses (just setting the stage for Humphrey’s and Baird’s eyewitness testimony). Fulks, 454 F.3d at 425. The district court did not explain how the government’s efforts to discover Mary Walker fell short, especially given that Walter Walker (though twice interviewed by police) never mentioned Mary Walker’s presence, no other bystander mentioned her presence, and only when the prosecution traveled to Oklahoma City did two bystanders reveal the new information that the government then pursued to locate Mary days later.
The district court abused its discretion in excluding Mary Walker’s testimony as the reasoning applicable to excluding the other eighteen witnesses did not apply to her differing circumstances. When the government in its motion for clarification and reconsideration alerted the district court to this mischaracterization of Mary Walker’s discovery, JA 517, the court denied the government’s motion to reconsider without clarifying this point, JA 546. The district court’s failure to specify how the prosecution’s efforts to discover Mary Walker fell short does not “in and of itself warrant[ ] reversal,” infra at 467, but strengthens our “definite and firm conviction that the [district] court ... committed a clear error of judgment in the conclusion it reached.” United States v. Dixon, 413 F.3d 540, 544 (6th Cir.2005) (quoting United States v. Wagner, 382 F.3d 598, 616 (6th Cir.2004)).
The Other Eighteen Witnesses. As for the remaining eighteen witnesses, we reject as an abuse of discretion the district court’s assessment that a reasonable investigation would have turned up the Rogers assault earlier. The district court reasoned (consistent with Young’s argument) that, since the government did not draw the assault information from Humphrey through four prior interviews, those interviews lacked the thoroughness of the pretrial interview. Yet the record as a whole counters the court’s assumption. After all, the government put Humphrey through four successive interviews, Detective Leiker required him in at least one of those interviews to reveal everything he knew about the conspiracy, and Humphrey testified before a grand jury. The court counted the absence of evidence of non-cooperation by Humphrey as a strike against the government’s claim of diligence. The passage of time, the number of interviews, and Humphrey’s cooperation are relevant, but no one disputes that he nevertheless failed to disclose the tangential matter of Rogers’s assault until late in the process, despite queries meant to elicit such information. Gregory, 410 F.2d at 1019 (noting that the government cannot probe a reticent witness about an event it does not know exists). And when the fifth interview produced this information, a reasonable assessment required crediting the government’s diligent pursuit of evidence to back it up. Indeed, within two weeks the government provided Young with the witnesses’ names and relevant information discovered from Humphrey’s pretrial interview. Contrary to the district court’s conclusion, this case is not analogous to Fernandez, where the government was negligent when it simply failed to pursue a promising lead. We thus determine that the district court abused its discretion in labeling as negligent the government’s failure to discover the Rogers assault earlier.
The district court’s reliance on Fernandez is misplaced for another reason. It cited the case for the proposition that “excusable negligence is not sufficient to permit the Government to add witnesses not on the witness list after the start of trial,” but Fernandez in fact concluded that the government’s failure to locate after-discovered witnesses “appears to be a simple mistake, but considering all the circumstances it is a mistake due to a lack of *466diligence and is not excusable.” 172 F.Supp.2d at 1278 (emphases added). Moreover, despite finding that the government had not exercised reasonable diligence, the Fernandez court went on to consider the impact of the new testimony on the defendants. Id. at 1280. Weighing “the rights of defendants in capital cases” with “the truth-finding function of our court system,” and despite the government’s lack of diligence, the court found partial exclusion the proper remedy. Id. at 1281.
4.
Although the government acted in good faith and conducted a reasonably diligent investigation, exclusion would be proper upon a showing of irreparable prejudice by Young. Fulks, 454 F.3d at 424. Because the district court never reached this issue, and because it is in the best position to consider this claim in the first instance, we remand for consideration of whether Young can establish that these late additions will irreparably harm his defense. See United States v. Tipton, 90 F.3d 861, 889 (4th Cir.1996) (defendant’s burden to show actual prejudice from tardily disclosed witnesses).
On remand the court should assess whether allowing the after-discovered witnesses’ testimony would frustrate § 3432’s 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. It is at this step — prejudice to the defendant without fault of the government — that courts look to adjournment as a remedial alternative to excluding evidence. If a defendant can establish actual prejudice through unfair surprise, “a trial court should first consider whether a brief adjournment to allow the defendant to meet the witness’s testimony would eliminate the prejudice caused by the surprise.” Fulks, 454 F.3d at 424 (citing Tipton, 90 F.3d at 889). In making this assessment, the court should consider only that prejudice resulting from a lack of notice, rather than any prejudice caused by the strength and nature of the after-discovered witness’s testimony. Id. And only if brief adjournment would not cure the defendant’s prejudice should the court preclude the witnesses from testifying. Id.; see also Fernandez, 172 F.Supp.2d at 1280-81 (excluding aspects of newly-discovered-witness testimony).
III.
We hold that the district court abused its discretion in choosing to exclude the relevant testimony in the absence of discovery abuses or bad faith on the part of the government. We therefore vacate the district court’s order and remand for proceedings consistent with this opinion.