Full opinion text
Opinion for the Court filed PER CURIAM. PER CURIAM: In November 2000, a grand jury returned a 158-count superseding indictment against sixteen defendants. The indictment alleged that, during the late 1980s and throughout the 1990s, those defendants conspired to run a large-scale and violent nareotics-distribution business centered in Washington, D.C. The defendants were charged with an array of offenses including narcotics conspiracy and racketeering conspiracy, as well as numerous counts of first-degree murder, assault with intent to murder, tampering with a witness or informant by killing, continuing-criminal-enterprise murder, and violent crime in aid of racketeering conspiracy. Many of the indicted defendants pleaded guilty to the charges, while the others went to trial in two separate groups. “Group One” consisted of six defendants, including the conspiracy’s alleged leaders, Kevin Gray and Rodney Moore. The Group One trial culminated in guilty verdicts and substantial sentences for each defendant. We affirmed most of those verdicts and sentences in United States v. Moore, 651 F.3d 30 (D.C.Cir.2011), aff'd in part sub nom. Smith v. United States, — U.S. -, 133 S.Ct. 714, 184 L.Ed.2d 570 (2013). “Group Two” consisted of five defendants from the November 2000 indictment: Deon Oliver, Franklin Seegers, Kenneth Simmons, James Alfred, and Ronald Alfred. Before their trial, the government obtained a separate six-count indictment against Keith McGill arising from his participation in the same conspiracy. The district court joined McGill for trial with the other Group Two defendants. On October 16, 2003, the Group Two trial commenced. Nearly six months later, on March 31, 2004, the jury began its deliberations. In April and May 2004, the jury found Oliver, Simmons, James Alfred, Ronald Alfred, and McGill guilty on all counts and found Seegers guilty on seven of the charged counts. After denying their posttrial motions, the district court sentenced all defendants to lengthy prison terms. Each received at least one term of life imprisonment, with the exception of Seegers, whose combined sentence of imprisonment amounted to forty years to life. The six Group Two defendants now appeal. Appellants challenge the sufficiency of the evidence against them on many of the charges. They also raise various claims concerning the conduct of the trial, including challenges to the district court’s dismissal of a juror during deliberations and to certain of the court’s evidentiary rulings. Appellants also allege prosecuto-rial misconduct and ineffective assistance of counsel, and one appellant (McGill) challenges his sentence. Upon review, we conclude that the evidence was sufficient to convict on all of the challenged counts. We also reject most of the claims of error or find that the alleged errors were harmless under the appropriate standard of review. We reverse the convictions on two counts against Seegers, however, and we also remand to the district court to determine whether any of appellants’ conspiracy convictions must be vacated because of a Confrontation Clause violation. Certain of McGill’s sentencing arguments have merit, moreover, and we remand for examination of claims by Simmons and Ronald Alfred that they received ineffective assistance of counsel before the district court. Appellants’ consolidated briefing to this court is organized under discrete issue headings designated by Roman numerals. Our section headings conform to appellants’ presentation of the issues (although we omit those section numbers denoting instances in which one appellant merely joined other appellants’ arguments). Detailed discussions of the facts, evidence, and proceedings will be set forth as necessary to address each issue appellants raise. We now proceed to address each issue raised by appellants. While certain of their arguments on each issue do not merit separate discussion, any arguments not directly addressed were fully considered and their disposition is so directly dictated by precedent as to not merit individualized discussion. I. Removal of Juror In their first joint argument, appellants challenge the district court’s dismissal of a juror for misconduct during deliberations. Appellants argue that the dismissed juror was inclined to vote for acquittal and that his dismissal violated their Sixth-Amendment right to conviction only by a unanimous jury. We find no error. We review the circumstances giving rise to the juror’s dismissal in some detail because the facts bear substantially on our review of the district court’s decision and our rejection of appellants’ challenge. A. 1. The circumstances leading to the juror’s dismissal are as follows. On April 1, 2004, one day after its deliberations began, the jury sent a note to the district court indicating that it was experiencing some difficulties with one juror. The note reported that “[o]ne juror has stated categorically that he does not believe in any testimony from any of the cooperating witnesses.” J.A. 1049. That juror had also told the others “that there is no other evidence presented by the prosecution either direct, circumstantial, non-cooperating [witnesses], et[c]. that would likely lead to an unanimous decision.” Id. The district court instructed the jury to continue its deliberations. After the next day of deliberations, the jury sent another note to the court relating to “one juror.” Id. at 1052. That note relayed that the juror “ha[d] stated from the beginning of our deliberation that he does not believe any testimony of or by the prosecution, defense or any law enforcement witness.” Id. Once again, the district court told the jury to continue its deliberations. On April 8, the jury sent a third note to the court, stating that it had “had serious and productive discussion.” - Id. at 1064. The note further reported that “[o]ne juror continues to refuse to accept any evidence and discuss or consider any verdict but not guilty or not proven for any count or charge for any defendant.” Id. In response, the court instructed the jury that, although “each juror is entitled to his or her opinions[,] [e]ach juror should ... exchange views with his or her fellow jurors[,] ... discuss and consider the evidence, ... consult with one another, and ... reach an agreement based solely and wholly on the evidence.” Id. at 1076. On April 14, the jury sent back two more notes in quick succession. The first note requested portions of the trial testimony. It also stated: “In addition, we have one juror # 9, that refuses to participate in any and all deliberations for this trial.” Id. at 1078. The second April 14 note raised a separate issue concerning the same juror (Juror # 9). It stated: On April 13, 2004, I Juror [# 12] observed Juror # 9 throughout deliberations writing notes or things out of his jury book . [with] all defendants^] charges, then at (April 13) the end [of] deliberations he pull[ed] 3 pieces of paper from that tablet (yellow)[,] fold[ed] them in half and placed them in his eye glass case. Id. at 1079. Another paragraph followed in different handwriting: Note as Foreman [Juror # 10] I am very disturbed] and eoneern[ed] by th[ese] actions on Jxiror # 9. If an alternate is available that would make me feel safer. Id. The district judge read the notes aloud when defense and government counsel gathered in the courtroom that day. The judge also shared additional information about what had transpired the previous evening. The judge stated that, as the jurors exited the van that transported them to a secure location at the end of each day, the foreman, Juror # 10, took aside the accompanying marshal and told him that Juror # 12 had witnessed Juror # 9 removing notes' from the jury room. According to the judge, Juror # 10 spoke with the marshal because the jurors had received instructions to take nothing out of the jury room. Juror # 10 suggested that the marshal search Juror # 9, which the marshal declined to do. Later that night, Juror # 10 called the marshal on his cell phone, expressing fear “[t]hat the jurors might be compromised by whatever it was that was taken out of the room.” Id. at 554748. The court asked the two sides for their views on how to proceed. The government expressed concern about Jxiror # 9’s potential misconduct in removing notes from the jury room and the fact that Juror # 9 had apparently made the foreman “feel unsafe”; the government also worried that Juror # 9 may have “given the impression to the jurors that their anonymity ha[d], perhaps, been compromised.” Id. at 5539-40. The government suggested that the court conduct individual voir dires of the three jxirors involved: Juror # 12, who claimed to have witnessed Juror # 9 writing and hiding the notes; Juror # 10, whom Juror # 12 had told about the incident; and Juror # 9. The government stressed the heightened security precautions the court had employed for the trial and explained that maintaining a “continued sense of safety, security, and anonymity... is all important as [the jurors] move foxrward in their deliberations.” Id. at 5564. In addition, the government argued that the first April 14 note provided more evidence that one juror — most likely Juror # 9 — had continuously refused to deliberate with the others. But the government suggested that the court defer consideration of that issue for the time being and instead focus on Juror # 9’s alleged removal of notes from the jury room. The defendants, for their part, moved for a mistrial. They argued that the jury’s notes had established that Juror # 9 was a holdout for the defense on at least some charges. In addition, counsel for Simmons asked the district court- whether it had specifically instructed “the jurors not to take any paper out of the jxiry room.” Id. at 5554. The court responded, “The marshals informed them they could not remove anything from the room.” Id. The court further explained that “their own notes have to be sealed. The room is locked each night after they leave, and they are told they can’t take anything out,” including notes. Id. Counsel asked, “That wasn’t an instruction given by the Court, that was something given by the marshals?” Id. at 5554-55. The court answered, “Right. It’s a standard instruction from the marshals, don’t take anything out of the room.” Id. at 5555. The district court decided to conduct individual voir dires of Jurors # 12, # 10, and # 9. The court first questioned Juror # 12. Juror # 12 described witnessing Juror # 9 “taking notes out of’ and “copying stuff’ from his juror notebook, which contained the indictments, the jury instructions, and the verdict forms. Id. at 5572. Juror # 12 recounted that, after the conclusion of deliberations for the day, Juror # 9 took three pieces of paper from his notepad containing “whatever he wrote,” ‘.‘folded them up,” and “slid them in his eyeglass case.” Id. Juror # 12 admitted that he did not know what Juror # 9 had written on those pieces of paper. But when the court asked whether Juror # 9 may have written “a grocery list or something like that,” Juror # 12 said he “d[id]n’t think it was,” because he had observed Juror # 9 “going through ... the middle of the (juror notejbook, and he was just taking little segments out of the book and just jotting them down, taking little segments out of the book, jotting them down, taking little segments out of the book, jotting them down.” Id. at 5576. Juror # 12 also told the court that, when Juror # 9 folded the pieces of paper and put them in his eyeglass case, he was “kind of looking out the side of his eye to see if anybody saw him.” Id. at 5578. “That’s what made me suspicious,” Juror # 12 said, “because he concealed it.” Id. Juror # 12 also stated that he was in the best position to observe Juror # 9’s actions because Juror # 12 was sitting beside Juror # 9. Finally, Juror # 12 mentioned that he reported Juror # 9’s actions because they contravened the court’s “instructions that we were not supposed to take anything home.” Id. at 5579. Next up was Juror # 10, the foreman. The court asked Juror # 10 to “walk [it] through” Juror # 12’s statements to Juror # 10 and the events leading up to the latest note. Id. at 5580. After doing so, Juror # 10 explained that he and Juror # 12 had safety concerns because “[w]e don’t know what [Juror # 9] [is] doing. He’s not participating.” Id. at 5581. When the court pressed further on why Juror # 9’s nonparticipation created a safety issue, Juror # 10 responded, “Well, because he’s distant. He’s been very distant, and I don’t know what’s in his mind. He’s been kind of stand-offish, and, again, everybody, to a certain degree, I think, feeling for the rest of the ten jurors, they’re very uneasy because they don’t know what to expect from that individual.” Id. at 5582. Juror # 10 added that he “didn’t sleep too well last night” and was “disturbed” by Juror # 9’s removing his notes because the jurors received “firm instructions not to remove any of the evidence or our notes. If he’s taking notes and putting it in his eyeglass case, that’s a problem and that’s against the rules.” Id. at 5585-86. “That brings a red flag to me,” Juror # 10 continued, “and I’m concerned about, you know, the other jurors [and] myself as it relates to this case. We don’t know what he’s doing. We don’t know what his intentions are.” Id. at 5586. The court next questioned Juror # 9. Juror # 9 readily admitted that he had put something from his juror notepad into his eyeglass case. He stated, however, that it was a single sheet of paper containing a “grocery list.” Id. at 5598. When asked about the list, Juror # 9 said he had written “ ‘[m]ilk, eggs, bread’ and ‘fruit.’ ” Id. at 5598-99. Juror # 9 confirmed that he had been sitting at the back of the room and away from the juror table when he wrote the note, though he denied that he had been trying “to be secretive about it in any way.” Id. at 5604. When the court asked whether he still had the note, Juror # 9 answered that he had thrown it away. The district court also told Juror # 9 that there had been “some concern about the way deliberations are going” and asked whether Juror # 9 wanted to disclose anything in that regard. Id. at 5599-5600. The court made clear, however, that it did not want Juror # 9 to discuss matters such as “guilty or not guilty, nothing like that.” Id. at 5600. Juror # 9 told the court that “whenever someone expresses an opinion that’s not the majority, they get shouted down. They don’t get a chance to express their opinion.” Id. Juror # 9 also stated that he had been looking at the evidence and expressing his opinions about the case to the others, but that “[t]hey don’t want to hear it.... They don’t want to listen.” Id. at 5605. After the court concluded its questioning of Juror # 9, it again heard from both sides about how to proceed. Defense counsel renewed their requests for a mistrial. No one suggested that the court should voir dire additional jurors. 2. The next day, on April 15, the court orally granted the government’s motion to remove Juror # 9 for good cause under Federal Rule of Criminal Procedure 23(b). The court, at the time, based its dismissal of Juror # 9 solely on his refusal to deliberate. The court’s statement from the bench referenced our court’s decision in United States v. Brown, 823 F.2d 591 (D.C.Cir.1987), which held that the dismissal of a juror on the basis of the juror’s views about the government’s evidentiary case had infringed the defendants’ Sixth-Amendment right to be convicted only by a unanimous verdict. The district court understood Brown to require it to make a factual finding, beyond a reasonable doubt, that Juror # 9 had refused to consider the law and the evidence at all (as opposed to considering the evidence and forming a decision in favor of acquittal). Based on the facts reported in the jury’s notes and the jurors’ voir dire testimony, the court concluded that Juror # 9 had been totally unwilling to consider the evidence or discuss the case with the others, in violation of his oath as a juror and the court’s instructions. The court also observed that its decision to remove Juror # 9 was not based on his removal of notes from the jury room. The court stated that, while it found it “likely that [Juror # 9] was writing some notes,” the court could not “resolve[] beyond a reasonable doubt” whether “it was a grocery list” or “something about the case.” J.A. 5623. The government asked the court to reconsider its decision, arguing that the note-removal incident afforded an independent basis to remove the juror for misconduct. The government also offered its understanding that the factual findings underlying that ground for dismissal need not be made beyond a reasonable doubt. The court responded, “If the standard is preponderance of the evidence, I would agree with you.” Id. at 5625. But the court at the time was “not clear that that is the proper standard. If that’s the proper standard, then I think you’re right.” Id. When the jury returned the next day, on April 16, the court informed the jurors that Juror # 9 had been excused for reasons not relevant to their deliberations and that an alternate would be joining them. The court told the reconstituted jury to begin its deliberations anew. One week later, on April 23, following a motion by the government, the court issued an order determining that Juror # 9’s removal of notes from the jury room constituted an independent basis to remove the juror for good cause. While the court had previously been uncertain whether it needed to make findings supporting that ground for dismissal under a more stringent standard than a preponderance standard, it now “found by a preponderance of the evidence that Juror # 9’s misconduct of removing notes” afforded a “basis to remove him for good cause.” Id. at 1088. The court made factual findings concerning the note-removal incident in which it credited Juror # 12’s “observations of the conduct of Juror # 9.” Id. at 1087. The court, thus found, consistent with Juror # 12’s account, that Juror # 9 had “cop[ied] passages from his juror notebook onto his note pad” and had “then removed three pages from his note pad and placed them in his eyeglass case.” Id. The court also credited Juror # 12’s testimony that Juror # 9 had acted in a “secretive, covert manner, attempting to avoid being seen by other jurors.” Id. The court observed that it did “not believe” and did “not credit the testimony of Juror # 9 regarding this incident.” Id. at 1088. And the court stated that Juror # 9’s actions were “a violation of the court’s instructions to the jurors that they must not remove anything from the jury room.” Id. at 1087. The court noted that safety considerations also informed its finding of good cause to excuse Juror # 9 based on his removal of notes from the jury room. “Needless to say,” the court explained, “the safety and security of the jurors are matters that are of the utmost importance in this case/’ especially given the unique “security procedures that are in place in this trial and the nature of the charges.” Id. at 1088. The court recounted Juror # 10’s statement that “this incident ‘disturb[ed]’ him” and his resulting request that Juror # 9 be replaced with an alternate so that he would “feel safer.” Id. The court concluded “that' Juror # 9’s misconduct of removing notes from the jury room constitutes an alternative and independent basis to remove him for good cause.” Id. The court explained that “[tjhis misconduct, standing alone, would have required his removal from the jury panel, even absent the evidence of his refusal to deliberate.” Id. On April 26, the reconstituted jury returned guilty verdicts on all counts for four of the defendants — Oliver, Simmons, James Alfred, and Ronald Alfred. On May 4 and 10, the jury returned its verdicts for the remaining two defendants, McGill and Seegers, finding McGill guilty on all counts and Seegers guilty on six counts. B. Federal Rule of Criminal Procedure 23(b) provides that, “[ajfter the jury has retired to deliberate, the court may permit a jury of 11 persons to return a verdict, even without a stipulation by the parties, if the court finds good cause to excuse a juror.” Fed.R.Crim.P. 23(b)(3). Here, instead of proceeding with eleven jurors, the district court replaced Juror # 9 with an alternate and instructed the reconstituted jury to begin its deliberations anew. See Fed.R.Crim.P. 24(c)(3) & advisory committee’s note to 1999 amendment. Appellants challenge the dismissal of Juror # 9 as a violation of their Sixth-Amendment rights (but do not separately challenge the decision to replace him with an alternate rather than proceed with eleven jurors). A variety of issues that may arise in the course of jury deliberations can constitute “good cause” to excuse a juror under Rule 23(b), including illness, family emergency, or, as here, jury misconduct. See United States v. Vartanian, 476 F.3d 1095, 1098 (9th Cir.2007). “Jury misconduct” consists of “action by jurors that is contrary to their responsibilities.” 6 Wayne R. LaFave et al., Criminal Procedure § 24.9(f) (4th ed.2004). “Much of the jury behavior considered to be misconduct is prohibited specifically in preliminary instructions,” such as removing materials, discussing the merits of the case with a coworker or family member, giving false testimony during voir dire, or refusing to deliberate. Id. “[A] district court, based on its unique perspective at the scene, is in a far superior position than [a court of appeals] to appropriately consider allegations of juror misconduct.” United States v. Boone, 458 F.3d 321, 329 (3d Cir.2006); see United States v. Sobamowo, 892 F.2d 90, 95 (D.C.Cir.1989). As a result, we review a district court’s decision to excuse a juror only for an abuse of discretion. United States v. Ginyard, 444 F.3d 648, 651 (D.C.Cir.2006). In certain circumstances, the Sixth Amendment constrains the district court’s discretion to remove a juror under Rule 23(b). In United States v. Brown, we held that “a court may not dismiss a juror during deliberations if the [juror’s] request for [his or her own] discharge stems from doubts the juror harbors about the sufficiency of the government’s evidence.” 823 F.2d at 596. Dismissal of a juror on grounds of her unwillingness to convict based on the evidence, we reasoned, would plainly violate a defendant’s Sixth-Amendment right to be convicted only by a unanimous jury. Id. But we noted “the problem” that the precise reason for a juror’s request to be dismissed — or, equivalently, for one juror’s suggestion that another juror be dismissed, see United States v. Symington, 195 F.3d 1080, 1086 (9th Cir.1999)—“will often be unclear.” Brown, 823 F.2d at 596. The high premium our system puts on the secrecy of jury deliberations precludes a trial court from “delv[ing] deeply into a juror’s motivations.” Id.; see Symington, 195 F.3d at 1086. A court thus may “prove unable to establish conclusively the reasons underlying” a juror’s request to be dismissed. Brown, 823 F.2d at 596. The Brown court adopted an approach erring on the side of Sixth-Amendment caution. “[I]f the record evidence discloses any possibility that the request to discharge stems from the juror’s view of the sufficiency of the government’s evidence,” we stated, “the [trial] court must deny the request.” Id. Applying that approach to the facts before us, we found that the record revealed a “substantial possibility” that the juror in question had “requested to be discharged because he believed that the evidence offered at trial was inadequate to support a conviction.” Id. In light of that possibility, we concluded that the juror should not have been dismissed, and we reversed the convictions. And although Brown dealt specifically with a juror’s own request to be discharged, our court and other courts applying Brown’s approach (or a variant thereof) have adhered to the same analysis when a juror’s removal stems from another juror’s allegations or from circumstances that otherwise come to the court’s attention. See United States v. Carson, 455 F.3d 336, 352 (D.C.Cir.2006) (per curiam); Symington, 195 F.3d at 1085-87; United States v. Kemp, 500 F.3d 257, 304-05 (3d Cir.2007); United States v. Abbell, 271 F.3d 1286, 1302 (11th Cir.2001); United States v. Thomas, 116 F.3d 606, 622 (2d Cir.1997). Appellants contend that Brown controls this case and mandates a new trial. They argue that, by the time of the jury’s April 14 notes to the district court— and certainly after the court completed its individual voir dires of Jurors # 12, # 10, and # 9 — the record revealed a likelihood that Juror # 9 was a holdout for the defense. They further submit that there was a possibility that the other jurors’ allegations about Juror # 9’s refusal to deliberate stemmed from Juror # 9’s substantive view of the government’s case — that is, when the other jurors accused Juror # 9 of nonparticipation in deliberations, they in fact were condemning him for his inclination to acquit based on the evidence. In those circumstances, appellants conclude, Brown obligated the district court either to keep Juror # 9 or to declare a mistrial. The government, on the other hand, argues that Juror # 9 could be dismissed notwithstanding Brown because, rather than form a conclusion about the sufficiency of the government’s evidence, he refused to deliberate altogether. An outright refusal to deliberate, the government submits, constitutes a valid basis for dismissal notwithstanding Brown. In the alternative, the government contends that the dismissal of Juror # 9 can be sustained based on what the district court explained was an “alternative and independent basis” for the juror’s discharge, J.A. 1088 — viz., that Juror # 9 had removed case-related notes from the jury room in violation of the court’s instructions. We agree with the latter argument and rest our decision exclusively on that ground. We therefore have no occasion to assess whether, had the district court based its good-cause dismissal solely on Juror # 9’s refusal to deliberate, its decision would have run afoul of our decision in Brovm. In resting our decision on the district court’s “alternative and independent” finding that Juror # 9’s removal of case-related notes from the jury room constituted misconduct justifying his dismissal, we take guidance from our decision in United States v. Ginyard, 444 F.3d 648. Ginyard clarified that Brown does not stand in the way of dismissing a known holdout juror for reasons independent of his views about the evidence. Id. at 652. The jurors in Ginyard told the trial court that their deliberations had been “heated” and that they were “deadlocked.” Id. at 650 & n. 1. One note asked the court how they should handle “a juror who has stated that they do not believe the testimony of several witnesses and does not offer reasons based on evidence.” Id. The next day, Juror 429 asked to be relieved from service to pursue a job opportunity through his rehabilitation program that might soon elapse. Id. After briefly questioning Juror 429 about the employment issue, the court announced that it would dismiss Juror 429 for good cause — i.e., to assure preservation of his job opportunity. Id. at 651. But before the court implemented the dismissal, it received information revealing that Juror 429 was likely the holdout referenced in the earlier communications and might have doubts about the government’s evidentiary case. Id. at 651-52. The court proceeded to dismiss him anyway, and the remaining jurors found the defendants guilty. Id. On appeal, the government conceded that Juror 429’s dismissal was in error under Brown because the court discharged the juror despite learning that he may have been a holdout for the defense. Notwithstanding the government’s concession, we found that Brown “does not control.” Id. at 652. We acknowledged that, by the time of Juror 429’s dismissal, the record revealed a “ ‘possibility that’ Juror 429 believed that ‘the government had failed to present sufficient evidence to support a conviction.’ ” Id. (quoting Brown, 823 F.2d at 597) (brackets omitted). We explained, however, that the Sixth-Amendment interests safeguarded by Brown do not always preclude a district court from exercising its discretion to dismiss a known holdout juror for good cause. “Were a holdout juror to request dismissal because he was experiencing' a heart attack,” for instance, “Brown would not prevent a district court from excusing that juror under Rule 23(b) for good cause, even if the record suggested that the juror independently had doubts about the sufficiency of the evidence.” Id. Instead, Brown bars a juror’s dismissal “only [in] those situations where the ‘request for discharge stems from doubts the juror harbors about the sufficiency of the government’s evidence.’ ” Id. (quoting Brown, 823 F.2d at 596). We found “no evidence that Juror 429 sought dismissal, or was dismissed, because of his doubts about the government’s evidence.” Id. Rather, “the record indicate[d] that his request stemmed entirely from an employment-related need.” Id. We nonetheless ultimately vacated the convictions because we concluded that the district court had conducted an inadequate inquiry into whether Juror 429’s employment needs in fact rendered him unable to continue. Id. at 653-55. But what is critical for present purposes is our explanation that “Brown is not implicated” unless “there is some causal link between a juror’s holdout status and the juror’s dismissal.” Id. at 652. Ginyard thus establishes that, even if a trial court knows a juror may harbor doubts about the government’s evidentiary case, the Sixth Amendment does not always insulate the juror from removal. See id.; accord United States v. Edwards, 303 F.3d 606, 634 (5th Cir.2002). Rather, if the court forms an independent, good-cause justification for removing the juror that bears no “causal link” to the juror’s “holdout status,” the court may excuse the juror even if the juror “independently had doubts about the sufficiency of the evidence.” Ginyard, 444 F.3d at 652. That understanding applies here. Initially, the district court based Juror # 9’s dismissal solely on his refusal to deliberate. Regardless of whether that ground would have involved the sort of “causal link between [the] juror’s holdout status and the juror’s dismissal” that would implicate Brown, id., the court later found that Juror # 9’s misconduct in taking notes from the jury room “constitute[d] an alternative and independent basis to remove him for good cause.” J.A. 1088. Because that distinct ground bore no “causal link” to Juror # 9’s “holdout status,” the court could dismiss the juror on that basis even if he “independently had doubts about the sufficiency of the evidence.” Ginyard, 444 F.3d at 652. As we explained in another juror-dismissal case, “[t]he judge plainly stated his reasons for the dismissal” — Juror # 9’s secreting notes out of the jury room in violation of the court’s instructions — and those reasons “had nothing to do with the juror’s view of the case.” Carson, 455 F.3d at 352. That kind of misconduct — unlike a juror’s refusal to deliberate or a juror’s intent to nullify — poses no inherent potential for confusion with a juror’s evidence-based inclination to acquit. Like the juror’s job-related availability at issue in Ginyard, 444 F.3d at 652, or the juror’s mental condition and possible deception at issue in Carson, see 455 F.3d at 350-52, the dismissal of Juror # 9 for clandestinely taking case-related notes out of the jury room bears no connection to any ideas he might have formed about the strength of the government’s case. That misconduct instead “was a violation of the court’s instructions to the jurors,” and, the court noted, also raised safety concerns in the minds of the other jurors who knew about it. J.A. 1087-88. The court thus concluded that “[t]his misconduct” independently justified Juror # 9’s “removal from the jury panel,” regardless of Juror # 9’s refusal to deliberate with other jurors. Id. at 1088. Of course, if an ostensibly independent basis for a juror’s dismissal in fact amounts to a pretext, and the actual ground for dismissal involves the juror’s views about the adequacy of the government’s evidence, our decision in Brown would be directly implicated. See Carson, 455 F.3d at 352 (considering defendants’ argument that the district court’s good-cause finding was pretextual). Here, appellants suggest such a pretext by seeking to cast doubt on the district court’s reliance on Juror # 9’s removal of notes from the jury room as a “post hoc rationalization.” Appellants’ Br. 102. We are unpersuaded. It is true that, when the court initially announced its decision to dismiss Juror # 9 in an oral ruling from the bench, the court declined to rely on the note-removal ground, instead relying solely on Juror #9’s refusal to deliberate. But even at that time, the court indicated its inclination to “agree” with the government that Juror # 9’s taking of notes provided an “independent” ground for “removing] him from these deliberations.” J.A. 5625. The court observed that, if its factual findings supporting that ground for dismissal could be made by a “preponderance of the evidence,” it “would agree” that Juror “Number 12, over Number 9,” has the correct “version of the facts” and that Juror #9’s misconduct would justify his dismissal. Id. But the court was “not clear” at that time whether it would need to choose Juror # 12’s version of the incident over that of Juror # 9 under a more stringent, “beyond a reasonable doubt” standard, in which event the court could not definitively resolve the factual dispute in favor of Juror # 12’s account. Id. By the time of the court’s written ruling several days later, however, the court concluded that preponderance-based findings would be adequate, enabling it to make “additional findings” that “credited] the testimony of Juror # 12,” and ultimately to determine that “Juror # 9’s misconduct of removing notes from the jury room constitute[d] an alternative and independent basis to remove him for good cause.” Id. at 1087-88. We see no basis for questioning the court’s determination in that regard — or its good faith in reaching that conclusion— based merely on the sequence of events. The court was plainly concerned about Juror # 9’s alleged removal of notes from the outset — as soon as it first heard about the incident from the marshal and from the jury’s second April 14 note describing what Juror # 9 had done. The allegations about Juror # 9’s removal of notes, not his alleged nonparticipation in deliberations, provided the impetus for the court’s decision to conduct voir dires of the jurors aware of the incident. As in Ginyard, “there is no evidence that Juror [# 9] ... was dismissed” on this independent ground “because of his doubts about the government’s evidence.” Ginyard, 444 F.3d at 652. “On the contrary, the record indicates that” this basis for Juror # 9’s dismissal “stemmed entirely” from his removal of case-related notes from the jury room. Id. The district court accordingly found that “[t]his misconduct, standing alone,” justified “his removal from the jury panel, even absent the evidence of his refusal to deliberate.” J.A. 1088 (emphasis added). That was because “[t]his misconduct” — entirely independent of his refusal to deliberate with the other jurors— amounted to “a violation of the court’s instructions to the jurors” and also raised safety concerns in the minds of those jurors who knew about it. Id. at 1087-88. Nor do we think the district court erred in reaching its factual conclusions underlying that ground for dismissal — in particular, in crediting Juror • # 12’s account of the note-removal incident instead of Juror # 9’s own version — under a preponderance standard. Because our decisions have established no explicit standard-of-proof threshold for factual findings undergirding a court’s dismissal of a juror for misconduct, the district court’s initial uncertainty is understandable. But the court was correct in ultimately concluding that it could find that Juror # 9 had committed the misconduct of removing notes from the jury room under a preponderance standard rather than some more stringent standard. When a juror’s alleged misconduct justifying her dismissal is unconnected to her possible “doubts about the government’s evidence,” Ginyard, 444 F.3d at 652 — the only situation we have occasion to consider here — there is no cause for requiring the court to conclude that the misconduct occurred by any heightened evidentiary threshold beyond the usual preponderance standard. See, e.g., Bourjaily v. United States, 483 U.S. 171, 175, 107 S.Ct. 2775, 97 L.Ed.2d 144 (1987). To be sure, even in cases involving a potential ground for a juror’s dismissal that is fully independent of her known status as a possible holdout for the defense, the court must still conduct an adequate inquiry before finding the existence of the independent basis warranting her discharge. As we explained in Ginyard, while “[o]ur holding in Brown may not control the outcome” when there is no qonnection between the ground for dismissal and a juror’s “view of the evidence, the district court, upon having reason to believe the juror is a holdout, has an enhanced duty to determine the precise circumstances of the juror’s availability lest the action of the court interfere with a defendant’s Sixth Amendment right to a unanimous verdict.” 444 F.3d at 654 (internal citation omitted). And in Ginyard, we ultimately reversed the convictions because the district court had “never determined” the “precise circumstances” of the juror’s potential inability to serve due to employment-related reasons — i.e., whether the juror in fact would relinquish an employment opportunity if he continued his service. Id. We noted that the juror himself “had indicated that he might be able to serve several additional days without losing the job opportunity.” Id. “Yet the district court made no attempt to ascertain whether or not this was true.” Id. The court, we concluded, should have inquired into the matter further. Id. at 654-55. Here, by contrast, the district court did not “rely on an unexamined state of uncertainty to draw the inference” that Juror # 9 had committed disqualifying misconduct by removing case-related notes from the jury room. Id. Rather, the court conducted a fully adequate factual inquiry. Upon receiving Juror # 10’s (the foreman’s) written account of what had transpired, the district court questioned every juror with information about the incident. Juror # 10 testified that he had no reason to believe any other juror saw what Juror # 9 was doing, and nothing said by the other two jurors — Jurors # 9 and # 12— called that assertion into doubt. Under those circumstances, the court reasonably decided against asking additional jurors about the episode. Any such inquiry ran the risk of fueling rumors or further unsettling or distracting the jury. Based on the court’s voir dire of the threp jurors, it found that Juror # 9 copied “passages from his juror notebook onto his note pad” and then removed those notes in a “secretive, covert manner, attempting to avoid being seen,” in “violation of the court’s instructions to the jurors that they must not remove anything from the jury room.” J.A. 1087. The court’s findings to that effect, by necessity, were based on its credibility determinations about the voir dire testimony of the three jurors. And we have emphasized that “[t]he district court, having observed the demeanor of [a] juror [during voir dire questioning], is in the best position to determine the credibility of’ the juror’s statements. United States v. Gartmon, 146 F.3d 1015, 1029 (D.C.Cir.1998). For that reason, we are highly reluctant “to second guess the conclusion of [an] experienced trial judge,” when, as here, that conclusion was “based in large measure upon personal observations that cannot be captured on a paper record.” United States v. Ruggiero, 928 F.2d 1289, 1300 (2d Cir.1991). That is particularly so when nothing in that paper record calls the court’s credibility assessments into question. The district court was under no obligation to accept Juror # 9’s account that he merely wrote down “[a] grocery list” containing only the words “[m]ilk, eggs, bread” and “fruit.” J.A. 5598-99. Juror # 12 described Juror # 9 as repeatedly copying down information for some period of time from his jury notebook and then removing three pieces of paper from his notepad while attempting to avoid detection, all of which would be inconsistent with merely jotting down a short, innocuous grocery list. That testimony directly conflicted with - Juror # 9’s statements that he wrote down just four words, removed but one piece of paper, and made no attempt to conceal what he was doing. Keeping in mind that the district judge was in a position to observe the jurors’ demeanor, we cannot say that the judge was wrong to “eredit[ ] the testimony of Juror # 12 regarding his observations of the conduct of Juror # 9,” and to “not credit the testimony of Juror # 9 regarding this incident.” Id. at 1087-88. Perhaps recognizing the difficulty of questioning the district court’s credibility determinations, appellants argue that, even if Juror # 9 had furtively removed case-related notes from the jury room, that conduct should not have led to his dismissal. Appellants initially contend that the district court (as opposed to the marshals) never instructed the jurors that their notes must remain in the jury room. Assuming that a distinction between an instruction from the district court and one from the marshals should matter, it is true that the court, in an exchange with counsel immediately preceding its voir dire of the jurors, stated that the marshals were the ones to instruct the jury that they could not remove materials from the jury room. But regardless of the court’s recollection at that moment, the court in fact had told the jury at the outset of trial that, “[a]t the end of each day, you will take [any notes] ■with you to the jury room and seal them” and that those items would be kept in the locked jury room overnight. Id. at 182425. The instructions also explained that “[n]o one ... will ever look at any of your notes” and that the materials would “be destroyed” following the jury’s delivery of the verdict, id. at 1825 — making all the more clear that the prohibition’s aim was to preserve the notes’ secrecy. Indeed, two other jurors shared their (unprompted) understanding that Juror # 9’s removal of case-related notes violated the judge’s instructions. We are also unpersuaded by appellants’ contention that the prohibition itself was misguided because a juror’s removal of notes from the jury room is no different than her retention of her own memories of the evidence. A trial court can readily conclude that a juror’s removal of written material from the jury room carries a greater risk that the material could be inadvertently seen by — or intentionally shared with — someone else. Even assuming Juror # 9 did nothing more than copy passages out of his juror notebook verbatim, “[allowing the jury to take home the indictment or the jury instructions ‘leaves the deliberative process needlessly vulnerable to a variety of potential problems’ by ‘increasing the chances that individual jurors may want to discuss these matters with family members or friends’ and by ‘making it easier for jurors to research legal issues on their own.’ ” United States v. Esso, 684 F.3d 347, 354 (2d Cir.2012) (quoting State v. Morgan, 423 N.J.Super. 453, 33 A.3d 527, 539 (App.Div.2011)). Moreover, appellants’ effort to challenge the need for a bar against removing notes from the jury room disregards that Juror # 9 not only violated the court’s instruction to that effect, but then compounded his misconduct by also giving false testimony about the incident under oath. Appellants further argue that, even if Juror # 9 committed misconduct, the court should have re-instructed the jurors not to remove their notes rather than dismiss the juror straightaway. We are unable to conclude that the court abused its discretion under Rule 23(b) by choosing the latter course. A trial court’s zone of discretion under Rule 23(b) includes considerable leeway to determine the appropriate response to a finding of juror misconduct based on the court’s firsthand assessment of the nature and degree of misconduct and the effect on the trial proceedings. In that regard, the circumstances here are unlike those in Ginyard. There, we found fault in the district court’s failure to conduct a further inquiry before discharging the juror, especially given that the juror himself suggested that he could continue to serve without losing his job opportunity. See 444 F.3d at 654-55. Whether he should be dismissed turned on a factual question warranting further examination— i.e., whether the juror’s employment opportunity in fact would be relinquished if he were to continue to serve. Here, by contrast, whether Juror # 9’s misconduct should lead to his dismissal did not turn on any such factual question warranting further inquiry. Instead, it turned on the district court’s contextual assessments about the gravity of the misconduct and the consequences of allowing him to continue to serve. We see no abuse of discretion in the court’s determination that, by removing jury notes in violation of the court’s instructions and then giving false testimony about the incident, Juror # 9 committed misconduct warranting his dismissal. See, e.g., United States v. Vega, 72 F.3d 507, 512 (7th Cir.1995) (finding no abuse of discretion in a court’s dismissing a juror who disobeyed instructions, including by removing notes from the jury room); United States v. Fryar, 867 F.2d 850, 853 (5th Cir.1989) (finding no abuse of discretion in a court’s dismissing a juror who lied to the judge under oath). Moreover, the court noted that its decision to discharge Juror # 9 for good cause was additionally informed by the incident’s implications for the jurors’ sense of safety and security. As the court referenced in its written findings, the scale of the criminal enterprise and the nature of the charges against the defendants — including murder, attempts to intimidate potential witnesses through killings, and RICO conspiracy involving multiple acts of violence — caused the court to employ unusually stringent security measures to protect the jurors. The court had empaneled an anonymous jury, which entailed a conclusion that “there is a strong reason to believe the jury needs protection.” Moore, 651 F.3d at 48 (quoting United States v. Edmond, 52 F.3d 1080, 1090 (D.C.Cir.1995)). The jurors were seated behind a locked bulletproof wall during trial, and they were assembled and dropped off in private locations, escorted each way by the marshals. Even with those protections in place, some potential jurors expressed fear during jury selection about being picked for duty and worried that their anonymity could be compromised. Those concerns came to the fore once Juror # 9’s misconduct came to light. Neither the district court nor the jurors knew exactly what Juror # 9 had written down or what he had done with it. But Juror # 12 observed that, whatever it was, Juror # 9 had tried to hide it. And the district court credited the observation that Juror # 9 had acted “in a secretive, covert manner, attempting to avoid” detection. J.A. 1087. As a result of Juror # 9’s behavior, Juror # 10 felt “disturbed” and expressed concerns for his and other jurors’ anonymity and safety; he shared that he had lost sleep over the incident. Id. at 5585-86. The court considered that testimony against the backdrop of prior incidents raising concerns about the security and independence of the jurors. Previously, the court had learned that the supervisor of one of the alternate jurors had been regularly attending the trial and maintaining contact with the alternate juror; the supervisor had grown up with one of the defendants, Ronald Alfred, knew him well, and was seen gesturing to Alfred during trial. The court dismissed that alternate juror. There was also a likely instance of witness intimidation (discussed in greater detail below) involving a defense witness’s receipt of a folder containing a photo of his murdered son shortly before the witness was to take the stand at trial. In that context, the district court understandably noted that “the safety and security of the jurors are matters that are of the utmost importance in this case” when it ruled that Juror # 9’s removal of notes from the jury room warranted his dismissal. J.A. 1088. In the end, subject to constitutional limitations, a “trial court has a great deal of discretion in deciding to excuse a juror for cause,” and “[a]n appellate court ordinarily will not second-guess such a determination.” United States v. Essex, 734 F.2d 832, 845 (D.C.Cir.1984). We find that the district court’s alternative rationale for Juror # 9’s dismissal based on his removal of jury notes amounted to a good-cause' ground for his discharge. We thus perceive no abuse of discretion in the court’s dismissal of Juror # 9 under Rule 23(b). II. Government Overview Testimony In reviewing the trial of the Group One defendants in Moore, we condemned the government’s use of an FBI agent as an “overview witness.” See 651 F.3d at 54-61. In appellants’ trial — which took place before we released our decision in Moore — the government used that same FBI agent in substantially the same manner. We reiterate Moore’s disapproval of such an overview witness and its conclusion that overview testimony might be, in certain circumstances, sufficiently prejudicial to warrant reversal of a defendant’s convictions. Those circumstances are absent here, however. Appellants forfeited their objections to the overview witness’s testimony by failing to raise them at trial, leaving us to review only for plain error. As in Moore, we discern no reversible error under that forgiving standard of review. A. As in the Group One trial reviewed in Moore, the government began its case-in-chief in the Group Two trial with the testimony of FBI Agent Daniel Sparks, the lead agent investigating the narcotics conspiracy at issue in both cases. Agent Sparks testified as an overview witness, presenting background information in support of the government’s case. Sparks highlighted the crucial role that cooperating witnesses can perform in unraveling a conspiracy. Narcotics conspiracies, Sparks explained, are in large part “based on everybody keeping quiet.” J.A. 1862. “[Ojnce you penetrate that conspiracy” with cooperating witnesses, Sparks stated, “you get an inside[r] that can tell you what’s going on.” Id. At that point, a conspiracy is “like a house of cards[.] [I]t begins to crumble.” Id. Sparks also testified that, due to their value to the prosecution, cooperating witnesses may be threatened by their coconspirators and often require witness protection. A basic “ground rule[ ]” for cooperating witness testimony, Sparks explained, is that the cooperator must provide “[t]ruthful information.” Id. at 1866-67. Though cooperators are assured that any information provided will not be used against them — a rule designed to make them “feel comfortable to provide the information”— Sparks noted that law enforcement still works to vet any cooperating witness for truthfulness. Id. at 1865, 1867. Officers do not “take [information] at face value,” Sparks explained; rather, they work to “corroborate or verify” that information by cross-referencing it with police reports, historical homicide files, and testimony from other witnesses. Id. at 1867-68. He then further described how cooperators may earn leniency in exchange for their cooperation, including via “5(K)” letters (requests for sentencing departures under U.S.S.G. § 5K). The sentencing judge would be the one to evaluate “the full extent” of a witness’s cooperation, Sparks observed. See id. at 1874-76. At the close of his testimony, Sparks presented two exhibits designed to tie the facts of the ease together for the jury. He first showed the jury an exhibit with pictures of twenty-two individuals under indictment for the alleged conspiracy and identified which individuals (i) were on trial in the instant proceeding; (ii) were on trial in separate proceedings; and (iii) had pleaded guilty and would serve as cooperating witnesses in the current trial. Finally, Sparks introduced a map of the District of Columbia showing the site of each murder and attempted murder allegedly connected to the conspiracy. B. In Moore, the government used Agent Sparks in essentially the same fashion. Sparks “testified as the first witness in the government’s case-in-chief,” and “[h]is testimony provided an overview of the government’s case, setting forth for the jury the script of the testimony and evidence the jury could expect the government to present in its case-in-chief.” Moore, 651 F.3d at 54-55. “Further, [Sparks] expressed his opinion, based on his training and experience, about the nature of the investigation conducted in th[e] case.” Id. at 55. Of particular relevance, Agent Sparks testified in the trial of the Group One defendants “that it was important, in his view, to use cooperating witnesses in this case because it was ‘the only way’ to gain ‘access to the inside information.’ ” Id. at 59. While acknowledging that cooperating witnesses are “criminals,” he also testified that those witnesses “know what’s going on,” and that their testimony is “the only way to put these kinds of cases together.” Id. (brackets omitted). Sparks further noted that cooperating witnesses were debriefed “to ‘get complete and truthful information,’ ” and that the FBI worked “to ‘try and verify’ the information ‘just to make sure the person is truthful.’ ” Id. (brackets omitted). At trial and on appeal, the Moore defendants objected to Sparks’s testimony. They argued that his overview testimony “improperly permitted the government ... to elicit FBI Agent Sparks’s opinions about the charged crimes, the reasons for appellants’ actions in various circumstances, the nature of the charged conspiracy and the relationships between cocon-spirators, including the cooperating co-conspirators who testified as government witnesses, and the strength of the evidence — all before the government had presented such evidence.” Id. at 55. We agreed. Sparks’s testimony, we found, “crossed the line in a number of instances.” Id. at 59. While he “could properly describe, based on his personal knowledge, how the gang investigation in this case was initiated, what law enforcement entities were involved, and what investigative techniques were used,” what “he could not do was present lay opinion testimony about investigative techniques in general,” “opine on what generally works and what does not,” “anticipate evidence that the government would hope to introduce at trial,” or “express an opinion, directly or indirectly, about the strength of that evidence or the credibility of any of the government’s potential witnesses, including the cooperating co-conspirators.” Id. at 61. We noted that the “clear implication” of Sparks’s testimony “was that the government had selected only truthful co-conspirator witnesses for the pre-indictment investigation, from whom the jury would hear during the trial.” Id. at 59-60. We found that result to be highly problematic, and we therefore joined the other courts of appeals “that have addressed the issue in condemning” the government’s use of overview witness testimony. Id. at 60. We noted that there were several “obvious” problems posed by the government’s use of an overview witness. Id. at 56. “First, the jury might treat the summary evidence” from the overview witness “as additional or corroborative evidence that unfairly strengthens the government’s case.” Id. Second, the overview witness might serve as a conduit for the introduction of “otherwise inadmissible evidence.” Id. And third, an overview witness “might permit the government to have an extra [opening] argument.” Id. We also determined that the “[a]voidanee of those dangers is largely beyond the ability of the district court, much less the defense.” Id. at 60. Ultimately, however, we found no reversible error. We concluded that “the prejudice resulting from the admission of FBI Agent Sparks’s overview testimony, to the extent it was inappropriate, was ameliorated.” Id. at 61. We noted several mitigating factors, including that “[e]ach instance of FBI Agent Sparks’s improper testimony identified by appellants was later confirmed by admissible evidence at trial”; that the district court employed limiting instructions; and that the trial produced “overwhelming evidence of appellants’ guilt.” Id. Accordingly, we concluded that “the error did not ‘affect the outcome of the district court proceeding,’ and hence appellants are not entitled to reversal of their convictions because of improper overview testimony by FBI Agent Sparks.” Id. (quoting United States v. Sumlin, 271 F.3d 274, 281 (D.C.Cir.2001)) (internal citation and brackets omitted). In a subsequent decision, we again noted the problems associated with overview testimony (again by Agent Sparks), but we concluded that the admission of the testimony was harmless error due to the lack of prejudice. United States v. Bostick, 791 F.3d 127, 145-47 (D.C.Cir.2015). C. Both parties agree that Moore establishes the appropriate framework for our review today. Given that appellants raise on appeal substantially the same objections made at trial in Moore, to what was substantially the same testimony by the same witness, we agree. In Moore, we recognized that challenges to overview witness testimony could be framed as objections to the introduction of otherwise-inadmissible evidence or as assertions of prosecutorial misconduct. See 651 F.3d at 55. We assume that appellants make both claims, though — as in Moore — our conclusions are unaffected by any distinctions between the two. Id. Our standard of review depends on whether appellants properly preserved any objections to Sparks’s overview testimony. Failure to raise an objection at trial results in the forfeiture of the objection, yielding review only under the more forgiving “plain error” standard. United States v. Wilson, 605 F.3d 985, 1022 (D.C.Cir.2010). Appellants argue that they preserved their challenge to Sparks’s overview testimony by lodging a number of objections during the course of Sparks’s testimony. But the objections identified by appellants were not objections to Sparks’s testimony qua overview witness. They instead were objections to various discrete pieces of Sparks’s testimony' — for instance, an objection to Sparks’s testimony about his military background. Accordingly, appellants’ objections at trial “gave ‘no indication to the judge that the defense was claiming that the entire line of questioning was improper.’ ” United States v. Ramirez-Fuentes, 703 F.3d 1038, 1042 (7th Cir.2013) (quoting United States v. McMahan, 495 F.3d 410, 418 (7th Cir.2007)) (brackets omitted). Our review thus is for plain error only. The first two elements of the plain-error standard are met — i.e., that a “legal" error” exists and that the error is “clear.” United States v. Brown, 508 F.3d 1066, 1071 (D.C.Cir.2007) (quoting United States v. Sullivan, 451 F.3d 884, 892 (D.C.Cir.2006)). The key hallmarks of Sparks’s testimony — in particular, his opining on the truthfulness of cooperating witnesses as a whole' — mirrored the testimony we condemned in Moore. But plain-error inquiry does not end there. To satisfy the third prong of the plai