Before Higginbotham, Smith, and Engelhardt, Circuit Judges. Patrick E. Higginbotham, Circuit Judge: A jury convicted a medical doctor and two pharmacists of drug-related crimes under the Controlled Substances Act for their roles in a pill-mill operation. We AFFIRM. I. A grand jury indicted Dr. Caesar Capistrano and two pharmacists, Wilkinson Oloyede Thomas and Ethel Oyekunle-Bubu (“Bubu”), (collectively, “Appellants” or “Defendants”) for roles in a “pill-mill” operation.[1] Prosecutors charged Appellants with three drug-distribution conspiracies that each spanned from 2011 to 2020.[2] Bubu and Thomas, who both owned pharmacies, were also charged with possession with intent to distribute controlled substances.[3] While Capistrano is a medical doctor, he also owned multiple clinics. The Government’s theory was that he prescribed controlled substances and Bubu and Thomas filled those prescriptions and others, on a host of occasions, for which there was no legitimate medical purpose. The conspiracy involved recruiters coordinating with pill mills and complicit pharmacies to fill unlawful prescriptions for street-level distribution. Recruits posed as patients, getting prescriptions issued in their names in exchange for cash. The recruiters would then fill the recruits’ prescriptions at complicit pharmacies, paying exclusively in cash. Charged with drug-distribution conspiracies and with possessing with intent to distribute controlled substances,[4] defendants invoked § 841(a) of the Controlled Substances Act, which exempts doctors and pharmacists from criminal liability for distributing “authorized” controlled substances.[5] By regulation, prescriptions are “authorized” if they are (1) “issued for a legitimate medical purpose” and (2) “by an individual practitioner acting in the usual course of his professional practice.”[6] At trial, the Government offered extensive evidence, including text messages, wiretaps, surveillance, cooperator testimony, and records from Defendants’ businesses and homes. The jury found Defendants guilty on all counts. The district court sentenced Capistrano and Bubu to 240 months’ imprisonment and Thomas to 151 months. Defendants timely appealed. II. We turn first to the standard of our review and then challenges to the sufficiency of the evidence. A. “The standard of review for insufficiency-of-the-evidence claims depends on whether the claims were preserved.”[7] As the three defendants preserved their challenges to the sufficiency of the evidence against them by motions filed at trial, our review is de novo.[8] Nonetheless, a “defendant seeking reversal on the basis of insufficient evidence swims upstream.”[9] Our review is “highly deferential” to the jury’s finding of guilt.[10] We will uphold the jury’s verdict so long as “any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt.”[11] A verdict can be supported by “reasonable inferences from the evidence,”[12] but “may not rest on mere suspicion, speculation, or conjecture, or on an overly attenuated piling of inference on inference.”[13] “Circumstances altogether inconclusive, if separately considered, may, by their number and joint operation, especially when corroborated by moral coincidences, be sufficient to constitute conclusive proof.”[14] “[T]he jury is free to choose among reasonable constructions of the evidence.”[15] 1. Bubu challenges two counts of possession with intent to distribute controlled substances in violation of 21 U.S.C. § 841(a)(1),[16] which requires the Government to prove beyond a reasonable doubt that Bubu knowingly possessed a controlled substance—here, Hydrocodone and Carisoprodol— which she intended to distribute.[17] Bubu’s “[p]ossession may be actual or constructive, may be joint among several defendants, and may be proved by direct or circumstantial evidence.”[18] “Constructive possession is ‘the knowing exercise of, or the knowing power or right to exercise, dominion and control over the proscribed substance.’”[19] Bubu argues that there was “no evidence that [she] knew of the particular medical conditions of Ms. Cooks and Mr. Parks.” The Government counters that there was abundant evidence of Bubu’s involvement with recruiters—including her instructing recruiters to “remove [her] logo from vials” and leaving their recruits in the car, as having so many people in the area was a bad look—as well as other “numerous red flags” about Bubu’s pharmacy operations, including only accepting cash and charging unusually high prices for controlled substances, priced per pill rather than by a typical prescription quantity. While § 841 does not require that Bubu knew the patients’ medical conditions, there must be sufficient evidence that Bubu knew the prescriptions she filled for Cooks and Parks were unauthorized.[20] Bubu concedes that she “knew some of the prescriptions emanating from Dr. Capistrano’s clinic were invalid.” Cooks was one of Capistrano’s recruiters who filled her and her recruits’ prescriptions at Bubu’s pharmacy.[21] Bubu filled Cooks’s Hydrocodone prescription from Capistrano for the highest possible prescription strength. Cooks testified that she directly interacted with Bubu, including phone calls. Parks was one of Cooks’s recruits, and Cooks filled his prescriptions at Bubu’s pharmacy. Bubu’s dispense log, signed by Bubu, shows that Bubu filled Parks’s and another one of Cooks’s recruit’s prescriptions from Capistrano for controlled substances. In sum, given the evidence of Bubu’s knowledge of Capistrano’s clinic’s practices and her involvement with recruiters, “a rational trier of fact could have found the elements of the crime beyond a reasonable doubt.”[22] 2. Thomas argues that the evidence cannot show he knew any prescriptions were “invalid,” and both Thomas and the Government point to “red flags.”[23] We turn to the evidence, asking whether a rational jury could find beyond a reasonable doubt that Thomas knew the prescriptions were unauthorized.[24] The testimony of recruiter Wayne Kincade, and his text messages with Thomas, played a prominent role in the Government’s case. Kincade started using Thomas’s pharmacy to fill his recruits’ prescriptions after another recruiter recommended the pharmacy. Kincade told Thomas he was picking up other people’s prescriptions because they did not want to drive to the pharmacy. Kincade regularly texted and called Thomas about prescriptions and sent pictures of recruit’s IDs if needed. Kincade testified that Thomas operated “by the book,” but also that Thomas “fronted” Kincade prescriptions—once more than $1,000 worth—because Thomas trusted that he would pay for the drugs later. Kincade paid for the prescriptions in cash—three or four at a time for $265 each—sometimes outside of business hours. When Kincade tried to fill more prescriptions each time, Thomas told him it was best to space them out so he would fill some now and the rest the next day. Thomas warned Kincade to “be careful cashing those Capistrano prescriptions because he [is] in the black book.” Thomas’s pharmacy stopped accepting Capistrano’s prescriptions but still filled prescriptions from Dr. Noel, another defendant who pleaded guilty. Kincade never told Thomas he sold drugs or suggested that he was breaking the law, but Kincade affirmed that, like everyone else involved in the conspiracy, Thomas “knew what [he] was doing.” Thomas argues that Kincade’s statement that Thomas “wasn’t like some of the other pharmacists” and was “by the book” means “it was clear to Mr. Kincade that Mr. Thomas was not a party to a pill mill case.” But this view is not the only one fairly drawn from Kincade’s testimony that Thomas “knew what [he] was doing.” While Thomas imposed some requirements on filling other people’s prescriptions, a reasonable jury could infer that Thomas was trying to cover himself, as the Government argued. We may not reweigh the evidence, or second-guess “[c]redibility choices that support the jury’s verdict.”[25] Juries are “entitled to weigh . . . circumstantial evidence, drawing inferences for or against [a defendant's] knowing and voluntary participation in a conspiracy with others.”[26] Where, as here, there are multiple reasonable constructions of the evidence, “the jury is free to choose among [them].”[27] “[T]he ‘relevant question is whether, after viewing the evidence in the light most favorable to the prosecution, any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt.’”[28] Considered in the requisite light, the evidence was sufficient for a rational juror to find the requisite mens rea here. 3. To sustain a conviction for conspiracy under 21 U.S.C. § 846, the Government must prove beyond a reasonable doubt “(1) an agreement between two or more persons to violate the narcotics laws, (2) the defendant’s knowledge of the agreement, and (3) the defendant’s voluntary participation in the conspiracy.”[29] Capistrano argues he cannot be convicted of conspiracy because there was no record that he “had any contact, of any type whatsoever,” with the pharmacists. Capistrano also argues that there was “no testimony whatsoever that [he] said []or did anything.” The Government counters that there was abundant evidence of a conspiracy, and Capistrano’s involvement with it as well—including Capistrano instructing individuals to issue prescriptions when he was not there, and prescribing significant quantities of Alprazolam, Carisoprodol, and Hydrocodone, which accounted for 99.7% of his prescriptions—as well as other actions with respect to Capistrano’s operations. We have long held that “all members of a conspiracy are not required to know every other member for a conspiracy to exist.”[30] Given the attendant record, Capistrano’s claim falls short. B. In sum, our highly deferential review compels us to conclude that “‘the totality of the evidence permits a conclusion of guilt beyond a reasonable doubt’” for all Appellants on all challenged claims.[31] III. Bubu and Capistrano challenge the jury instructions given at trial. The challenges fail. A. Generally, “this court reviews jury instructions for abuse of discretion and harmless error.”[32] “However, when a defendant fails to object to jury instructions, we review for plain error.”[33] Since neither Bubu nor Capistrano objected to the jury instructions, we review for plain error.[34] To establish plain error, one must show that: “(1) the district court erred, (2) the error was clear or obvious, (3) the error affected his substantial rights, and (4) this court should exercise its discretion to correct the error because the error seriously affects the fairness, integrity, or public reputation of judicial proceedings.”[35] By the metric of plain error review of jury instructions, a district court does not err when “the instruction, taken as a whole, is a correct statement of the law.”[36] “[W]hen a jury instruction omits . . . an essential element of an offense, the error may be severe enough to meet the plain-error standard.”[37] When reviewing a jury instruction, we must “consider the jury charge as a whole” and reverse only if the entire charge leaves us “with the substantial and ineradicable doubt whether the jury has been properly guided in its deliberations.”[38] In other words, to amount to plain error, the instruction “must ‘have meant the difference between acquittal and conviction.’”[39] After Appellants filed their initial briefs, the Supreme Court issued Ruan v. United States.[40] Ruan addresses the state of mind requirement to convict doctors under the Controlled Substances Act.[41] In Ruan, the Supreme Court overturned the convictions of two doctors for violating 21 U.S.C. § 841(a)(1), which makes it a federal crime, “[e]xcept as authorized . . . for any person knowingly or intentionally . . . to manufacture, distribute, or dispense . . . a controlled substance.”[42] Although the defendants could prescribe such substances to their patients, prescriptions are authorized only when a doctor issued it “for a legitimate medical purpose . . . acting in the usual course of his professional practice.”[43] The specific question at issue was whether it was “sufficient for the Government to prove that a prescription was in fact not authorized,” or whether the Government must also “prove that the doctor knew or intended that the prescription was unauthorized.”[44] The Court held that “the statute’s ‘knowingly or intentionally’ mens rea applies to authorization.”[45] So, “[a]fter a defendant produces evidence that he or she was authorized to dispense controlled substances, the Government must prove beyond a reasonable doubt that the defendant knew that he or she was acting in an unauthorized manner, or intended to do so.”[46] This Court then decided United States v. Ferris, which applied Ruan to pharmacist violations of § 841.[47] Emphasizing that it is the unauthorized nature of prescriptions that renders conduct wrongful, not the dispensation itself, this Court held that the Government must prove that a pharmacist “knowingly or intentionally filled unauthorized prescriptions for a patient.”[48] 1. Bubu raises two challenges regarding the jury instruction. We address each in turn. First, Bubu challenges the district court’s use of “or” rather than “and” in instructing the jury when a prescription is unauthorized. Section 841 makes it unlawful, “[e]xcept as authorized[,] . . . for any person knowingly or intentionally . . . to manufacture, distribute, or dispense . . . a controlled substance.”[49] A two-pronged definition provides that prescriptions for controlled substances are authorized if they are (1) “issued for a legitimate medical purpose” and (2) “by an individual practitioner acting in the usual course of his professional practice.”[50] Bubu argues that the district court erred in instructing the jury that “it could convict upon a finding that she acted either without legitimate medical purpose or outside the usual practice of medicine, measured objectively.”[51] The district court’s jury instructions incorrectly stated the law by omitting th emens rea element.[52] This satisfies the first two prongs of the plain error test.[53] That said, we find that this error does not warrant a plain error reversal. While it is true the district court erred, and that error was clear, “an instruction that omits an element of the offense does not necessarily render a criminal trial fundamentally unfair or an unreliable vehicle for determining guilt or innocence.”[54] To justify reversal on plain error review, Bubu must show that the error affected her substantial rights.[55] “‘As a general rule, an error affects a defendant’s substantial rights only if the error was prejudicial.’”[56] “‘Error is prejudicial if there is a reasonable probability that the result of the proceedings would have been different but for the error.’”[57] In other words, the likelihood of a different result must be enough to undermine confidence in the outcome of the proceedings.[58] Bubu fails to make this showing. Bubu’s failure to meaningfully address the third and fourth prongs of the plain error test either in her opening brief or in reply undermines her challenge.[59] Bubu’s initial brief does not argue that but for the error, there would be a reasonable probability she would be acquitted. Bubu even “assume[s] for the purpose of [substantial rights] that the [G]overnment presented sufficient evidence for a jury to find the defendant’s guilty knowledge under the correct standard,” but that because of the error, Bubu did not have a chance to defend herself.[60] Bubu’s concession shows that she did have the “chance to defend herself”—the opportunity to present evidence that could have raised doubts about her knowledge.[61] Additionally, the record shows that Bubu’s counsel spent substantial time arguing that Bubu did not knowingly commit a crime. Because Bubu failed to argue that but for the incorrect jury instruction there was a reasonable probability that she would have been acquitted, she does not satisfy the plain error test. Accordingly, although the district court erred— based on an intervening Supreme Court case it could not know about at the time—in instructing the jury, such error does warrant reversal. Bubu’s second challenge argues the district court erred by “tethering the pharmacist’s criminal liability to a doctor’s misconduct.” She argues that the instructions exclusively address doctors’ practices and not pharmacists’ practices and that any doctor’s unauthorized act—whether known or unknown by the doctor or pharmacist—could be imputed to a pharmacist. We conclude that reasonable minds can differ as to whether the instructions impute doctors’ misconduct to pharmacists, as the instructions simply ask the jury to consider each defendant’s “usual course of professional practice.” “[L]egal error must be clear or obvious, rather than subject to reasonable dispute.”[62] This was not. 2. Capistrano raises three jury-instruction challenges. First, Capistrano challenges the instruction given by the district court. The written jury charge correctly instructed the jury to determine whether the controlled substances were “(1) prescribed for what the defendant subjectively considered to be a legitimate medical purpose.” However, at trial, the district court misread the charge, telling the jurors to consider objectively legitimate medical purposes. Capistrano contends this warrants reversal. To be sure, we have recognized the problematic nature of inconsistent jury instructions.[63] And we have found reversible error when written instructions were contradictory on an issue that neither party addressed during closing argument.[64] But when reviewing jury instructions, we “rarely will reverse a conviction based on a district court’s insignificant slip of the tongue.”[65] A “district court’s apparent mistake [is] sufficiently remedied to render any resulting error harmless” when the jury is given a copy of the instruction, in which “[t]he contradictory, erroneous statement is nowhere to be found.”[66] “[T]he proper inquiry is not whether the instruction ‘could have’ been applied in an unconstitutional manner, but whether there is a reasonable likelihood that the jury did so apply it.”[67] Here, not only was there no error in the written instructions, the parties also spent extensive time discussing the subjective knowledge requirement during closing arguments.[68] Even though the district court misspoke, when “consider[ing] the instructions as a whole, the evidence presented, and the arguments of counsel[,]” we do not believe this error is “ so fundamental as to result in a miscarriage of justice.”[69] Accordingly, we find there was no reversible error.[70] Second, like Bubu, Capistrano challenges the district court’s use of “or” rather than “and” in instructing the jury when a prescription is unauthorized. Unlike Bubu, however, Capistrano does not argue that the knowledge requirement applies to both authorization prongs. Rather, like Bubu, Capistrano argues that both prongs must be satisfied. Because the Government need not prove both prongs, Capistrano fails to establish plain error. Lastly, Capistrano argues that “the trial court did not clearly explain nor adequately define to the jury what good faith means.” The district court’s jury instructions make no mention of good faith. However, good faith is not a required element of the offense.[71] Capistrano fails to show any error, plain or otherwise.[72] B. In sum, neither Bubu nor Capistrano have shown that any errors affected their substantial rights or that we should exercise our discretion to correct any such errors.[73] We reject Bubu and Capistrano’s arguments that we must vacate their convictions because of the jury instructions. IV. We next address Bubu’s other claims. Her challenges all fail. A. Bubu contends that the district court deprived her of her constitutional right to counsel at a critical stage of the proceeding—during sentencing—by allowing her to proceed pro se without a clear and unequivocal waiver.[74] “Sixth Amendment challenges to the validity of a waiver of counsel are reviewed de novo.”[75] To determine whether the district court violated Bubu’s right to counsel, we ask whether Bubu properly waived her right to counsel and whether the waiver was knowing and intelligent.[76] 1. A criminal defendant, by virtue of the Sixth Amendment, has the right to counsel at trial.[77] The right extends to the sentencing phase just as forcefully as to the guilt phase.[78] “Where a fundamental constitutional right, such as the right to counsel, is concerned, courts indulge every reasonable presumption against waiver.”[79] Without a clear election to forgo counsel, “‘a court should not quickly infer that a defendant unskilled in the law has waived counsel and has opted to conduct his own defense.’”[80] Defendants “can waive [their] right to counsel implicitly, by [their] clear conduct, as well as by [their] express statement.”[81] Further, defendants’ “‘refusal without good cause to proceed with able appointed counsel constitutes a voluntary waiver of’ the right to counsel.”[82] “To constitute waiver, such a refusal must take the form of ‘a persistent, unreasonable demand for dismissal of counsel.’”[83] But the right is not limitless. Applied here, a criminal defendant is not entitled to a particular counsel, just a competent one.[84] As we have described this right previously, “‘[a] defendant is entitled to counsel capable of rendering competent, meaningful assistance. . . . No defendant has a right to more.’”[85] The issue regarding Bubu’s representation was no minor dispute, but instead a continuous and long-running issue. At sentencing, Bubu repeatedly stated she did not want her current attorney, J. Stephen Cooper, to represent her. Bubu did not like the attorney previously appointed to her, so the district court allowed Bubu to hire Cooper, who was Bubu’s fourth attorney. The district court then instructed Bubu: “he is either going to be your lawyer, or you’re going to proceed pro se.” Cooper explained there was “some conflict” between Cooper and Bubu and that Bubu refused to talk to him.[86] The district court instructed Cooper to discuss the PSR and the dangers of self-representation with Bubu. After a 47-minute break, Cooper reported that Bubu refused to look at any documentation with him and when he spoke about the dangers of self-representation, she turned her back to him and said: “I’m representing myself.” Bubu told the district court she wanted a different lawyer to represent her. The district court spoke with the attorney Bubu wanted, who said he had not yet been retained to represent Bubu and that it would “not be feasible” to represent her at that time. The Government objected to Bubu bringing on a fifth attorney because “it seem[ed] like . . . a delay tactic” since Bubu had received “competent representation from her first lawyer through her fourth lawyer.” The district court agreed and, not wanting to keep delaying sentencing and recognizing Bubu’s “pattern” of “refus[ing] to talk to [her] attorneys[,]” denied Bubu’s request to fire Cooper and hire new counsel. When asked if she desired to represent herself, Bubu responded “No” but also insisted that Cooper could not represent her. When told she had to choose between two options: either Cooper representing her or representing herself, Bubu refused to answer the question, reiterating: “I want new counsel.” After more back and forth, the district court concluded: “you’ve made clear that you do not want Mr. Cooper to represent you in this case . . . So that means, ma’am, you are going to represent yourself.” The district court proceeded, then Bubu interjected to say: “I cannot represent myself right now, sir.” The district court asked Bubu to not interrupt him, and Bubu again said, “I cannot represent myself.” The district court asked if she wanted Cooper to come back, which she eventually agreed to. Cooper returned and argued that Bubu “needs some credit for an exemplary life prior to this event,” asked for a minimum guidelines sentence, and introduced Bubu’s children to speak on her behalf. Bubu’s conduct—which she concedes was “frustrating”—waived counsel. Bubu persistently and unreasonably demanded that her counsel be dismissed. After having already dismissed multiple attorneys and refusing to cooperate and communicate with Cooper—and even turning her back to him—she insisted she would represent herself. Although Bubu never told the court she wished to represent herself, her actions relinquished her right to counsel.[87] Bubu does not argue that she had good cause to not proceed with Cooper.[88] And we have long-held that “[a] defendant’s refusal without good cause to proceed with able appointed counsel constitutes a voluntary” decision to proceed pro se.[89] We find Bubu’s actions as a voluntary waiver of the right to counsel. 2. While Bubu may have voluntarily waived the right to counsel, we must next ask if it was done knowingly and intelligently.[90] Defendants must “be made aware of the dangers and disadvantages of self-representation.”[91] We require “district courts to exercise discretion in determining the precise nature of the warning provided to a defendant seeking to represent himself, depending on the circumstances of the individual case.”[92] “Although . . . the precise nature of appropriate warnings depends on the particularities of the case, we have generally required trial courts to provide warnings of substance, including at least a modicum of specificity.”[93] Bubu argues that even if she waived her right to counsel, it was not a knowingly and intelligent choice because the court did not advise her that repeatedly requesting a new lawyer or asking for a continuance would result in immediate self-representation. The record shows otherwise. The district court told Bubu, “I am not continuing the case any longer. And so that means today, you can represent yourself . . . or you can be represented by Mr. Cooper.” The sentencing transcript reveals the district court repeatedly advised Bubu against self-representation and of the disadvantages of self-representation. For example, the district court cautioned Bubu: “I’m going to advise you that, in my opinion, you will be far better off remaining with your retained attorney, Mr. Cooper. I think it is unwise of you to try to represent yourself.” The district court even instructed Cooper to discuss “dangers and disadvantages” of self-representation with Bubu. Bubu argues that the court should have to warn defendants that their conduct could result in self-representation. While sometimes district courts do this,[94] we have never imposed such a requirement[95] and we decline to do so today. Given the district court’s multiple warnings and attempts to reason with Bubu, we hold Bubu knowingly and voluntarily waived her right to counsel. B. Bubu challenges the district court’s refusal to grant a continuance. “A district court’s denial of a continuance is reviewed for abuse of discretion.”[96] “Trial judges have ‘broad discretion’ in ruling on motions for a continuance.”[97] “[T]he movant must show that the denial resulted in specific and compelling or serious prejudice.”[98] “This is true even where the denial of the continuance will shorten the amount of time available for preparation of the defendant’s case.”[99] “In review, we evaluate each situation on a case-by-case basis and normally consider only the reasons for continuance presented to the trial judge.”[100] To establish that denying a continuance was an abuse of discretion, Bubu “must show that the denial resulted in ‘specific and compelling or serious prejudice.’”[101] We will uphold the decision below so long as it was not arbitrary or unreasonable.[102] Bubu argues the district court abused its discretion in denying her continuance request made at sentencing because she was unprepared to represent herself. While Bubu’s briefs identify the correct standard, she fails to address the “specific and compelling or serious prejudice” that resulted from the denial of the continuance. To be sure, Bubu maintains that she needed more time to prepare to discuss her PSR objections. That said, she fails to explain how this discussion would have aided her defense. She therefore cannot establish prejudice.[103] The record also indicates that prior to Bubu’s request, the district court paused proceedings and instructed Bubu and her counsel to review the PSR. She refused to do so. Any resulting prejudice was by her own hand. Bubu’s counsel was available and capable of representing her, and she may not indefinitely postpone hearings to seek representation.[104] The district court acted well within its discretion in refusing to grant the requested continuance. C. Bubu argues that the district court erred by adopting the PSR without first hearing objections from her attorney, violating her Rule 32 rights, which require sentencing courts to “allow the parties’ attorneys to comment on the probation officer’s determinations and other matters relating to an appropriate sentence.”[105] Because Bubu did not object to the PSR below, plain error review applies.[106] Bubu argues neither she nor her attorney had a chance to object. Nowhere does the Rule require courts to hear comments before ruling on PSR objections. The Rule governing parties’ opportunities to speak, Rule 32(i)(4)(A), provides that defendants and their attorneys must have an opportunity to speak “[b]efore imposing sentence,” not before adopting the PSR.[107] Bubu argues but cites no support for the assertion that “[a]t least where the defendant proceeds pro se, the same reasoning suggests that the court errs when ruling on PSR objections without soliciting argument from the defendant.” We have noted that “‘[t]he touchstone of [R]ule 32 is reasonable notice’ to allow counsel adequately to prepare a meaningful response and engage in adversary testing at sentencing.”[108] Here, both Bubu and her attorney were given opportunities to speak at sentencing. While the Federal Sentencing Guidelines say that “[w]hen any factor important to the sentencing determination is reasonably in dispute, the parties shall be given an adequate opportunity to present information to the court regarding that factor[,]” it notes that counsel’s “ [w]ritten statements” may suffice.[109] That is what happened here. Bubu’s attorney filed written objections. Additionally, unlike Rule 32(i)(1)(B) and Rule 32(i)(4)(A), Rule 32(i)(1)(C) does not require courts to “give [defendants] a reasonable opportunity to comment,”[110] “address the defendant personally,”[111] or “provide the defendant’s attorney an opportunity to speak.”[112] Rule 32(i)(1)(C) instead requires that parties’ attorneys be allowed to comment.[113] At no point did the district court prohibit Bubu’s attorney from commenting. Bubu has not established that the district court committed a clear or obvious violation of Rule 32(i)(1)(C). D. Bubu challenges as improper hearsay the admission of an investigator’s testimony about an intercepted conversation between LaTonya Tucker, a receptionist for Capistrano who secured money from patients, and Ritchie Milligan, a recruiter, in which the two discuss “Little Barry Hill.”[114] Although evidentiary rulings are usually reviewed for abuse of discretion, a defendant must preserve the challenge through an objection.[115] We review unpreserved challenges for plain error.[116] Bubu argues she preserved the challenge by objecting to and referencing the presence of double hearsay in the challenged testimony at trial. But at trial, Bubu objected to a wiretapped conversation between Tucker and Milligan as double hearsay because it included “two different people talking.” The testimony about Jonathan McGillivray that Bubu challenges on appeal occurred after the district court overruled Bubu’s double hearsay objection. That objection did not preserve the error Bubu now urges because it was not “sufficiently specific to alert the district court to the nature of the alleged error and to provide an opportunity for correction.”[117] We therefore review for plain error.[118] Bubu contends this testimony is double hearsay because “[i]t reflected both the conversation between Ms. Tucker and Mr. Milligan and some prior conversation relating these facts about Mr. McGillivray to either Ms. Tucker or Mr. Milligan.” Bubu does not contest that the conversation between Tucker and Milligan is admissible under the conspiracy hearsay exclusion. She rather argues that Turner and Miller do not have personal knowledge of the information about McGillivray. But this contention brings no comfort. The record is insufficient to determine whether Turner or Miller obtained the information about McGillivray first-hand or in the furtherance of a conspiracy.[119] Any error was neither plain nor obvious. And there was substantial evidence about McGillivray and Bubu’s fraudulent transactions,[120] so even if we did find errors, they did not affect Bubu’s substantial rights or seriously affect her trial’s fairness. We find no reversible error. E. Bubu challenges the district court’s allowing a DEA agent to authenticate her signature as a lay witness. Since Bubu objected at trial, the district court’s ruling on the admissibility of evidence is reviewed for abuse of discretion subject to harmless error.[121] The metric is “unless manifestly erroneous,” we will not reverse.[122] At trial, the district court overruled Bubu’s objection to a DEA agent’s lay testimony identifying two of her signatures.[123] The agent gained familiarity with Bubu’s handwriting during the course of the investigation. Bubu argues that familiarity developed during a criminal investigation is “acquired for purposes of the litigation” and not admissible as lay witness testimony. While we have not addressed whether an investigator who develops familiarity about handwriting during an investigation may authenticate the handwriting as a lay witness, our sister circuits have. We are persuaded by their reasoning. Under Rule 901 of the Federal Rules of Evidence, a signature can be authenticated by “[a] nonexpert’s opinion that handwriting is genuine, based on a familiarity with it that was not acquired for the current litigation.”[124] “Testimony based upon familiarity acquired for purposes of the litigation,” on the other hand, must be provided as expert testimony.[125] The First, Second, Sixth, Eighth, and Eleventh Circuits all allow investigators who become familiar with handwriting in the process of solving a crime to testify at trial as lay witnesses.[126] “Each of those circuits has drawn a distinction, either explicitly or implicitly, between becoming familiar with someone’s handwriting ‘for the current litigation’ and doing so for the purpose of determining if the defendant has committed a crime.”[127] We found no sister circuit holding differently, nor did Bubu identify one. Here, the agent’s testimony was not merely a “one-shot comparison” where a witness identifies handwriting for the first time in the courtroom during trial.[128] Rather, over the course of the investigation, the agent reviewed 20,000 pages of prescriptions with witness signatures. Given that an “investigator is in the same position as any other lay witness who, as part of his job or in his day-to-day affairs, has seen examples of the defendant’s handwriting, such as the defendant’s ‘accountant, employee[,] or family member[,]‘”[129] we join our four sister circuits in holding that the district court did not err in admitting the agent’s testimony. V. Finally, we address Capistrano’s other claims. None is meritorious. A. Capistrano objects to statements made during the Government’s closing argument as mischaracterizing the facts. The statements were objected to at trial. We review for abuse of discretion.[130] “A criminal conviction is not to be lightly overturned on the basis of a prosecutor’s comments standing alone,” and “[t]he determinative question is whether the prosecutor’s remarks cast serious doubt on the correctness of the jury’s verdict.”[131] To determine whether there was prosecutorial misconduct, we ask whether “the prosecutor made an improper remark” and whether “the defendant was prejudiced.”[132] Prejudice is a “high bar.”[133] Capistrano objected to the Government’s assertion that he had “zero cancer patients.” The district court overruled the objection and instructed the jury: “you will remember what the evidence shows.” “The closing argument must be analyzed in the context of the entire case to determine whether it affected substantial rights of the accused. In making this determination, [we] should consider the strength of the [G]overnment’s case and the trial court’s instructions to the jury.”[134] The evidence shows that a “few” of Capistrano’s patients were diagnosed with cancer. But Capistrano did not treat patients for cancer, he treated them for “pain.” So when one of Capistrano’s employees was asked if they saw “any cancer patients at all[,]” she responded “ No.” Given the substantial evidence against Capistrano and the district court’s instructions to “remember what the evidence shows,” we find no reversable error. Indeed, the Government’s argument is consistent with the evidence. Moreover, if the evidence in the case to support a conviction is strong, it is unlikely that the defendant was prejudiced by any improper arguments made by the prosecutor in closing arguments.[135] B. Capistrano argues his counsel was ineffective because he did not request home detention, failed to make various objections, failed to investigate claims, failed to object to jury instructions, and failed to request a Franks hearing.[136] Yet we review a claim for ineffective assistance of counsel (“IAC”) on direct appeal “[o]nly when the record is sufficiently developed with respect to such a claim.”[137] That is, evidence or examples establishing deficient performance or prejudice.[138] We have none here. As the record is not sufficiently developed to evaluate Capistrano’s IAC claim, we decline to consider the claims on direct appeal.[139] C. Capistrano is proceeding pro se, so we must “interpret his brief liberally to afford all reasonable inference which can be drawn from them.”[140] By the rules, pro se “litigants must still brief the issues and reasonably comply with the standards of Rule 28 in order to preserve them.”[141] Failure to comply with this Court’s rules results in dismissal.[142] We will not address his remaining arguments as they either are frivolous or inadequately briefed.[143] VI. In sum, we AFFIRM Appellants’ convictions and sentences. There is sufficient evidence for a jury to draw reasonable inferences to support Appellants’ convictions. Bubu and Capistrano fail to make the showings necessary to warrant plain error reversal. Bubu’s refusal to be represented by her retained attorney amounted to a knowing and voluntarily waiver of counsel. Bubu fails to show the necessary prejudice for her challenges to the denial for a continuance, as well as permitting a DEA agent to authenticate her signature as a lay witness. The Government’s closing argument was consistent with the evidence. The record is not sufficiently developed to evaluate Capistrano’s IAC claim. And Capistrano’s additional claims are either frivolous or insufficiently briefed. AFFIRMED. Patrick E. Higginbotham, Circuit Judge, concurring in part and dissenting in part: Decades ago, Justice Oliver Wendell Holmes, Jr., and Judge Learned Hand, two of our nation’s preeminent legal minds, were having lunch, and after breaking bread, “as Holmes began to drive off in his carriage, Hand, in a sudden onset of enthusiasm, ran after him, crying, ‘Do justice, sir, do justice.’ Holmes stopped the carriage and reproved Hand: ‘That is not my job. It is my job to apply the law.’”1 “The exchange between the two judges is part of an age-old struggle to define the relation of law and justice and to determine to which the judge owes loyalty.”2 In Hand’s telling of the story, he did so only “to provoke a response” from Holmes, knowing full-well that he agreed with Holmes’s view of his juridical responsibility.3 And, indeed, as students of these two stalwarts and their jurisprudential philosophy know both believed their duty and fidelity was strictly to the law rather than to one’s individual concept of a just outcome.4 By contrast, those like Chief Justice Earl Warren or Judge J. Skelly Wright, two luminaries of their day, fall into the latter category.5 With regard to Bubu’s conviction on Count 3, the majority is loyal to neither. Though I join the remainder of the Court’s opinion vis-à-vis Bubu’s other convictions as well as those of her co-defendants, as I believe there is a miscarriage of justice afoot, I would not affirm the sentence imposed for her drug trafficking conviction in Count 3. I. One month after oral argument, Bubu’s counsel moved to file supplemental briefing raising a new claim: “whether the Court reversibly erred in imposing a sentence of 20 months on Count Three, when 21 U.S.C. §§ 841(b)(1)(E)(3) and 846 set forth a maximum of 12 months.”6 The unopposed motion for leave to file was directed to me as a single judge matter and granted, with a request that the Government respond.7 It did, “agree[ing] [that] the sentence exceeded the statutory maximum and that the sentence could not be greater than 12 months” and urging that “the Court [] reform the judgment to reduce the sentence” in accordance with the statutory maximum rather than remanding altogether.8 In other words, the Government conceded plain error urging that the panel correct the error rather than remand for a new sentencing hearing. II. When the Government confesses that a person is facing nearly a year in prison for which there is no legal basis—it matters. Nigh a century ago, the Supreme Court made clear that “[i]n exceptional circumstances, especially in criminal cases, appellate courts, in the public interest, may, of their own motion, notice errors to which no exception has been taken, if the errors are obvious, or if they otherwise seriously affect the fairness, integrity, or public reputation of judicial proceedings.”9 Twenty-six and a half years later, the High Court reaffirmed that principle.10 Since that pronouncement, our Court has taken that principle to heart, “recogniz[ing] an exception to” the general waiver rule “whereby we will consider a point of error not raised on appeal when it is necessary ‘to prevent a miscarriage of justice.’”11 The Federal Rules of Criminal Procedure specifically endow us with the authority to reverse a sentence on the basis of plain error, even though the defendant has not raised the issue on appeal.12 And of course, this issue was raised on appeal, albeit not in a timely fashion. To these eyes, the error at issue here falls squarely within this exception. This is no minor error, but one the Government concedes will subject Bubu to nearly one year of prison beyond her legal sentence. If the point is to impose discipline upon counsel for their shortcomings, it misses the mark. As Chief Justice Marshall wrote just over two centuries ago, “the power of punishment is vested in the legislative, not in the judicial department. It is the legislature, not the Court, which is to define a crime, and ordain its punishment.”13 Affirming this sentence beyond what Congress permits, as our Court does today, exceeds our power and usurps that of the Congress. Indeed, I can think of no clearer subject of “exceptional circumstances” worthy of action than an unlawful sentence.14 And in conceding the error, the Government asked this Court to correct the error and otherwise affirm rather than remand for resentencing.15 Our Court has corrected errors in unlawful sentences without remand for unlawful terms of supervised release16 or where the modification of the carceral term for one count did not impact the total imprisonment.17 I would remand the case and allow the able district judge to exercise his discretion. The form of the remedy aside—affirm with a modification or remand—inaction ought not be countenanced, as the Court’s opinion demands Ethel Oyekunle-Bubu stay in prison eight months more than Congress deemed permissible. ***** No jurisdictional bar prevents this Court from correcting this error.18 With respect, to these eyes, refusing to do so works a manifest injustice without principled justification. I accept the necessity of maintaining the guardrails of our court with its myriad rules of preclusion, but I would correct this error—and in doing so would be attending these rules, enabling their function without blinking at an injustice we are duty-bound to correct. This is not the pursuit of justice and fairness in the abstract. It is simply a citizen’s government refusing to enforce a prison sentence it confesses is illegal. With respect, I must DISSENT from affirming Bubu’s sentence for Count 3.
