Full opinion text
Affirmed by published opinion. Judge WILKINSON wrote the opinion, in which Judge NIEMEYER and Judge GREGORY joined. Judge NIEMEYER wrote a concurring opinion. OPINION WILKINSON, Circuit Judge: Defendant David Anthony Runyon appeals his conviction and capital sentence for conspiracy to commit murder-for-hire, among other charges stemming from the same course of events. For the following reasons, we affirm. I. A. On April 30, 2007, Cory Allen Voss, an officer in the United States Navy, was found dead of multiple gunshot wounds in his pickup truck in a parking lot in Newport News, Virginia. Three individuals were arrested in connection with the killing: Runyon; Catherina Voss (“Cat”), the victim’s wife; and Michael Draven. On February 13, 2008, a federal grand jury in the Eastern District of Virginia returned a five-count indictment charging all three with the following crimes: • Count One: conspiracy to commit murder-for-hire, in violation of 18 U.S.C. § 1958(a); • Count Two: carjacking resulting in death, in violation of 18 U.S.C. § 2119 and 18 U.S.C. § 2; • Count Three: bank robbery resulting in death, in violation of 18 U.S.C. § 2113(a) and (e) and 18 U.S.C. § 2; • Count Four: conspiracy to commit robbery affecting commerce, in violation of 18 U.S.C. § 1951(a); and • Count Five: murder with a firearm in relation to a crime of violence, in violation of 18 U.S.C. § 924(c)(1) and (j) and 18 U.S.C. § 2. The indictment also included the requisite notice of special findings for seeking capital punishment pursuant to the Federal Death Penalty Act (FDPA), 18 U.S.C. §§ 3591-3598, which governs multiple aspects of this case. The government further notified Runyon that it intended to seek the death penalty against him on July 17, 2008. Cat pleaded guilty to all counts and was sentenced to life imprisonment. Runyon and Draven were jointly tried before a jury beginning on June 30, 2009. At the end of the prosecution’s case on the question of guilt, the court granted the defendants’ motion to dismiss Count Three. The jury found both defendants guilty of Counts One, Two, and Five and not guilty of Count Four. The government did not pursue the death penalty against Draven. He received a sentence of life imprisonment, and this court affirmed his convictions in United States v. Draven, 417 Fed.Appx. 362 (4th Cir.2011) (per curiam). The district court conducted a death penalty eligibility hearing for Runyon on July 22, 2009. The previous day, the court had excused a juror whose mother had died the night before and replaced her with an alternate, and the court informed the parties of this substitution immediately before the eligibility hearing. Neither side presented additional evidence at the hearing, and on that same day, the jury found Runyon eligible to receive the death penalty as a threshold matter. The penalty selection phase commenced on August 19, 2009. The jury began deliberating during the afternoon of August 26, 2009. The next morning, the court excused a juror whose brother-in-law had passed away the night before, replacing her with an alternate. The jury returned its verdict that evening, recommending a sentence of death on Counts One and Five and a sentence of life imprisonment on Count Two. The court imposed the recommended sentences on December 4, 2009, and this appeal followed. B. The evidence adduced during the guilt phase of Runyon’s trial established the following factual foundations for his convictions. Cat and Draven began conducting an extramarital affair during the summer of 2006. The affair commenced when Voss, to whom Cat had been wed since 1999, was deployed aboard the USS Elrod. Cat and Draven hired Runyon, whom Draven met while participating in a drug study in February 2007, to murder Voss in hopes of gaining his Navy death benefits and life insurance proceeds. On April 20, 2007, Cat opened an account at a branch of the Langley Federal Credit Union in Newport News (“the LFCU”) with a five dollar deposit. Shortly before midnight on April 29, 2007, Cat sent Voss to the automated teller machine (“ATM”) at the LFCU to withdraw cash. Video surveillance showed that while Voss stood at the ATM, an unidentifiable intruder entered his pickup truck. Voss drove away from the ATM but returned a few minutes later and attempted another withdrawal, which was denied due to insufficient funds. Voss was found dead in his truck in a parking lot near the LFCU the next morning. He had been shot five times at close range. Four hollow-point bullets from a “.38 class” gun — which includes firearms capable of firing .357 magnum, .38 special, and 9 mm cartridges— were recovered from his body. The cause of death was three shots to the chest and abdomen. The prosecution presented a wealth of evidence proving that Runyon acted as the triggerman in a murder-for-hire conspiracy. The government established that on the day of the killing, Runyon purchased a .357 magnum handgun and ammunition in West Virginia, where he lived, and that a friend of his pawned the gun several months later. In the console of Runyon’s vehicle, law enforcement located a map of Newport News with notes referring to Voss, Voss’s vehicle, and the LFCU, as well as a photograph of Cat and Draven with their names, addresses, and a social security number written on the back. In Runyon’s current and former homes, investigators discovered phone numbers for Cat and Draven; a box of .357 magnum bullets with five missing; papers mentioning the LFCU and the travel time to Virginia; and a list of items including a taser, Spyderco knife, tarp, and trash bag, as well as boots, gloves, a black hoodie sweatshirt, and military-style pants. Moreover, a variety of telephone and email evidence showed that Cat, Draven, and Runyon had arranged the contract killing and attempted to orchestrate a cover-up. For example, while Runyon apparently asked for five hundred dollars up front, a Western Union money order showed that he received two hundred and seventy-five dollars from Draven’s brother on June 1, 2007. Finally, several witnesses testified that Runyon had boasted about killing Voss — or a military member or unidentified individual — for money. As mentioned above, at the close of the prosecution’s casein-chief, the court dismissed the bank robbery charge (Count Three). The jury ultimately convicted Runyon of conspiracy to commit murder-for-hire (Count One), carjacking resulting in death (Count Two), and murder with a firearm in relation to a crime of violence (Count Five) and found him not guilty of conspiracy to commit robbery affecting commerce (Count Four). C. The sentencing portion of the trial began with the eligibility phase, which determines whether a defendant meets the minimum statutory requirements for receiving the death penalty. Pursuant to the FDPA, a defendant convicted of certain crimes — including those charged in Counts One, Two, and Five here — can be declared eligible if the jury determines, unanimously and beyond a reasonable doubt, that one of four enumerated intent elements and at least one statutory aggravating factor are present. 'See 18 U.S.C. §§ 3591-3593. Here, the jury found that Runyon had intentionally killed Voss, see id. § 3591(a)(2)(A), and that the prosecution had established two statutory aggravating factors: first, that Runyon “committed the offense as consideration for the receipt, or in the expectation of the receipt, of anything of pecuniary value” and, second, that he “committed the offense after substantial planning and premeditation to cause the death of a person,” id. § 3592(c)(8), (9). The district court then proceeded to the penalty selection phase. Pursuant to the FDPA, the jury must decide by unanimous vote “whether the defendant should be sentenced to death, to life imprisonment without the possibility of release or some other lesser sentence.” Id. § 3593(e). In deciding whether to recommend capital punishment, the jury must determine “whether all the aggravating ... factors found to exist sufficiently outweigh all the mitigating ... factors found to exist to justify a sentence of death.” Id. The FDPA enumerates a number of statutory aggravating factors and mitigating factors (which are also often called “aggravators” and “mitigators”) and allows the parties to propose nonstatutory factors for the jury to consider as well. Id. § 3592(a), (c); id. § 3593(a). While the jury may find only aggravators for which the prosecution has provided notice as defined by the statute, the jury may find additional mitigators beyond those specifically proposed by the defense. Id. § 3592(a), (c); id. § 3593(a). Finally, the FDPA provides that, while findings concerning aggravating factors must be unanimous, findings concerning mitigating factors “may be made by 1 or more members of the jury, and any member of the jury who finds the existence of a mitigating factor may consider such factor established.” Id. at § 3593(d). After receiving an abundance of evidence over several days (from sixteen prosecution and twenty-one defense witnesses), the jury unanimously found that the prosecution had proved each of its proposed nonstatutory aggravators, in addition to the two statutory aggravators already found during the eligibility phase. As listed on the special verdict form, these were: • Nonstatutory Aggravating Factor One: Runyon “caused injury, harm, and loss to the victim, Cory Allen Voss, and the victim’s family and friends”; • Nonstatutory Aggravating Factor Two: In killing Voss, Runyon “utilized education, training, and experience that he received in college courses focused on criminal justice, and as a law enforcement and correctional officer, as an officer of the Kansas National Guard, and as a member of the United States Army”; • Nonstatutory Aggravating Factor Three: Runyon “engaged in acts of physical abuse toward women”; and • Nonstatutory Aggravating Factor Four: Runyon “has demonstrated a lack of remorse for murdering Cory Allen Voss as demonstrated by the evidence in the case.” The jury also unanimously found that Runyon had established seven of the fourteen mitigators proposed by the defense: • Statutory Mitigating Factor One: Runyon “does not have a serious criminal record,” see id. § 3592(a)(5); • Statutory Mitigating Factor Two: “Other persons equally culpable in the crime will not be punished by death,” see id. § 3592(a)(4); • Nonstatutory Mitigating Factor One: Runyon “will serve a sentence of life in prison without the possibility of release if not sentenced to death”; • Nonstatutory Mitigating Factor Nine: Runyon’s son “will suffer emotional harm if his father is executed”; • Nonstatutory Mitigating Factor Ten: Runyon’s mother “will suffer emotional harm if her son is executed”; • Nonstatutory Mitigating Factor Eleven: Runyon “served his country as a member of the United States Army and was honorably discharged”; and • Nonstatutory Mitigating Factor Twelve: Runyon “graduated from high school and earned an associate of arts degree ... and took further college courses to expand his education.” Additionally, the jury unanimously found two further nonstatutory mitigating factors that the defense had not expressly proposed: first, that Runyon “continued to witness and experience domestic violence and parental conflict/abuse from [his] mother and adoptive father” and, second, that Runyon’s brother “will suffer emotional harm if his brother is executed.” Finally, beyond these unanimous findings, ten or eleven of the twelve jurors found the following three proposed miti-gators: • Nonstatutory Mitigating Factor Two: Runyon “has worked and has been legally employed for all of his life”; • Nonstatutory Mitigating Factor Three: Runyon “committed acts of kindness and generosity for his neighbors and his community”; and • Nonstatutory Mitigating Factor Four: Runyon “grew up, witnessed, and experienced, domestic violence and parental conflict until his mother and biological father separated.” And eleven jurors agreed that the defense had established an additional mitigating factor that it had not specifically proposed: that Runyon “was given the impression that Cory Voss was molesting [Voss’s] daughter.” The special verdict form concluded by confirming that upon weighing the six aggravating factors (two from the eligibility phase and four from the penalty selection phase) and multiple mitigating factors, the jury'unanimously recommended a sentence of death on Counts One and Five and a sentence of life imprisonment without the possibility of release on Count Two. II. Runyon appeals both his convictions and his sentences on various grounds. Although the bulk of Runyon’s appeal focuses on the latter, we take up his conviction-related challenges first in the interest of chronological order. First, Runyon claims that the statutes on which Counts One and Two are premised are unconstitutional. Second, he contends that there was insufficient evidence to establish the jurisdictional element of Count One. We address these arguments in turn and, for the reasons that follow, find each unconvincing. A. Runyon asserts that both the federal murder-for-hire statute, 18 U.S.C. § 1958, which underlies Count One, and the federal carjacking statute, 18 U.S.C. § 2119, which underlies Count Two, are unconstitutional because their enactment exceeded Congress’s enumerated powers — in particular, the power to “regulate Commerce with foreign Nations, and among the several States.” U.S. Const, art. I, § 8, cl. 3. 1. The text of the murder-for-hire statute provides for punishment of whoever travels in or causes another (including the intended victim) to travel in interstate or foreign commerce, or uses or causes another (including the intended victim) to use the mail or any facility of interstate or foreign commerce, with intent that a murder be committed in violation of the laws of any State or the United States as consideration for the receipt of, or as consideration for a promise or agreement to pay, anything of pecuniary value, or who conspires to do so. 18 U.S.C. § 1958(a). While Runyon does not appear to challenge the statute’s constitutionality to the extent that it addresses “travel in interstate or foreign commerce,” he takes issue with the fact that it also purports to reach the mere “use [of] any facility of interstate or foreign commerce” to perpetrate contract killings. In particular, Runyon argues that a 2004 amendment changing the phrase “facility in interstate or foreign commerce” to “facility of interstate or foreign commerce” broadened the statute’s scope to such a degree as to cover virtually every murder-for-hire-including, for instance, a contract killing in which all of the parties were neighbors and the defendant made a single phone call to the victim’s residence. This argument fails by a wide margin. Pursuant to its commerce power, Congress may, among other things, “regulate and protect the instrumentalities of interstate commerce, or persons or things in interstate commerce, even though the threat may come only from intrastate activities.” United States v. Lopez, 514 U.S. 549, 558, 115 S.Ct. 1624, 131 L.Ed.2d 626 (1995). We agree with all of the circuits to address the question that the amended murder-for-hire statute meets this standard, as there exists “no meaningful distinction between the terms ‘facilities’ and ‘instrumentalities’ of interstate commerce.” United States v. Marek, 238 F.3d 310, 317 & n. 26 (5th Cir.2001); see also, e.g., United States v. Mandel, 647 F.3d 710, 720-23 (7th Cir.2011); United States v. Schaefer, 501 F.3d 1197, 1205 (10th Cir.2007) (listing “any facility of interstate ... commerce” language from § 1958(a) as an example of an “expansive exercise of [Congress’s] Commerce Clause powers”), overruled on other grounds by United States v. Sturm, 672 F.3d 891, 901 (10th Cir.2012). Congress’s enactment of the murder-for-hire statute, therefore, did not exceed its authority under the Commerce Clause. 2. Runyon’s constitutional attack on the federal carjacking statute meets the same fate. That statute criminalizes “takfing] a motor vehicle that has been transported, shipped, or received in interstate or foreign commerce from the person or presence of another by force and violence or by intimidation, or attempting] to do so,” where the perpetrator possesses “the intent to cause death or serious bodily harm.” 18 U.S.C. § 2119. Runyon’s challenge cannot overcome United States v. Cobb, which expressly rejected a Commerce Clause challenge to the same statute. 144 F.3d 319 (4th Cir.1998). First, we found that the carjacking statute’s inclusion of an “express jurisdictional element” tying the covered cars to interstate or foreign commerce “ ‘satisfies the minimal nexus’ ” required by recent Supreme Court precedent. Id. at 321-22 (quoting United States v. Wells, 98 F.3d 808, 811 (4th Cir.1996)). Second, and independently, we found that the carjacking statute “is also a valid exercise of Congress’s power to regulate an instrumentality of interstate commerce — cars,” citing the same language from Lopez on which we rely above and noting that multiple other circuits had come to the same conclusion. Id. at 322. The arguments pressed by Runyon, therefore, are both foreclosed by Cobb and unpersuasive on the merits. Because we also find that the prosecution’s evidence provided firm support for Runyon’s conviction on Count Two, that conviction stands. B. Next, Runyon argues that even if the federal murder-for-hire statute underlying Count One survives his constitutional challenge, there was insufficient evidence here to satisfy its jurisdictional hook. As indicated above, the murder-for-hire statute requires that the defendant, while possessing the requisite intent, (1) “travel[ed] in or eause[d] another (including the intended victim) to travel in interstate or foreign commerce” or (2) “use[d] or cause[d] another (including the intended victim) to use the mail or any facility of interstate or foreign commerce.” 18 U.S.C. § 1958(a). Here, the government argues that evidence establishing that Runyon drove his own truck from West Virginia to Virginia on the day of the murder sufficiently satisfied the first hook, on which the jury was instructed. Runyon contends, to the contrary, that travel “in interstate commerce” requires transport by commercial means (such as by bus, train, or plane). This is so, he argues, because if all travel between two or more states qualifies, the word “commerce” becomes entirely superfluous. Runyon’s argument, however, fails under United States v. Lentz, in which this court found that travel from one state to another in a personal vehicle constituted “transport[ ] in interstate or foreign commerce” under the federal kidnapping statute, 18 U.S.C. § 1201(a)(1). 383 F.3d 191, 196-97, 199-200 (4th Cir.2004). The text of the jurisdictional element at issue here is, of course, essentially identical to that considered in Lentz, and we therefore decline to interpret it differently. With the pertinent scope of the jurisdictional hook thus established, we turn to whether “substantial evidence” supported that element here. In answering that question, the appellate function is not to determine whether the reviewing court is convinced of guilt beyond reasonable doubt, but, viewing the evidence and the reasonable inferences to be drawn therefrom in the light most favorable to the Government, “whether the evidence adduced at trial could support any rational determination of guilty beyond a reasonable doubt.” United States v. Burgos, 94 F.3d 849, 862-63 (4th Cir.1996) (en banc) (quoting United States v. Powell, 469 U.S. 57, 67, 105 S.Ct. 471, 83 L.Ed.2d 461 (1984)). Runyon cannot clear this high hurdle, as the prosecution presented evidence from which the jury could readily infer that he drove his truck across state lines in order to kill Voss. Such evidence included the fact that investigators found in that very truck the map of Newport News and the photograph of Cat and Draven, both of which contained inculpatory notes, along with the fact that Runyon made a withdrawal from an ATM in West Virginia during the early afternoon hours of the day Voss was shot. The prosecution, therefore, sufficiently established the jurisdictional element of the murder-for-hire statute, and we accordingly affirm Runyon’s conviction on Count One. III. With the remainder of his arguments, Runyon shifts from contesting his convictions for killing Voss to contesting the jury’s sentencing recommendations on those convictions. Specifically, he challenges the nonstatutory aggravating factors charged by the prosecution and found by the jury, various evidence introduced by the prosecution to prove these factors, comments made by the prosecution during the closing arguments to the penalty selection phase of the trial, the district court’s substitution of jurors at points following the guilt phase, and the district court’s instructions to the jury at the end of the sentencing proceeding. Before considering the merits of these arguments, it is worth noting a few formidable obstacles that they must overcome. First, many of Runyon’s nonconsti-tutional challenges concern rulings by the district court that we review under the deferential abuse-of-discretion standard. See, e.g., Noel v. Artson, 641 F.3d 580, 591 (4th Cir.2011) (evidentiary rulings); United States v. Novak, 607 F.3d 968, 972 (4th Cir.2010) (jury instructions); United States v. Ollivierre, 378 F.3d 412, 417 (4th Cir.2004) (comments during closing arguments), vacated on other grounds by Ollivierre v. United States, 543 U.S. 1112, 125 S.Ct. 1064, 160 L.Ed.2d 1050 (2005). We are generally reluctant to reverse such discretionary rulings because district courts enjoy the considerable advantage of having perceived firsthand the witnesses who testified, the evidence that was introduced, and the arguments that were made at the proceeding under review. While we by no means abdicate our duty to carefully consider Runyon’s claims, we discharge this duty mindful of the risks of overstepping our limited role and impinging on trial courts’ essential trial-management functions. Second, in impugning multiple aspects of his sentencing proceeding, Runyon seems to overlook the fact that sentencing, including capital sentencing, is a wide-ranging process that accords considerable discretion to the sentencer — here, the jury. As the Supreme Court has held: “Once the jury finds that the defendant falls within the legislatively defined category of persons eligible for the death penalty, ... the jury then is free to consider a myriad of factors to determine whether death is the appropriate punishment.” Indeed, the sentencer may be given “unbridled discretion in determining whether the death penalty should be imposed after it has found that the defendant is a member of the class made eligible for that penalty.” Tuilaepa v. California, 512 U.S. 967, 979-80, 114 S.Ct. 2630, 129 L.Ed.2d 750 (1994) (citation omitted) (quoting California v. Ramos, 463 U.S. 992, 1008, 103 S.Ct. 3446, 77 L.Ed.2d 1171 (1983); Zant v. Stephens, 462 U.S. 862, 875, 103 S.Ct. 2733, 77 L.Ed.2d 235 (1983)). The FDPA reflects this broad conception of capital sentencing, permitting the jury to consider not only a number of expressly enumerated aggravating factors, but “any other aggravating factor for which notice has been given.” 18 U.S.C. § 3592(c). It also allows the parties to present aggravating or mitigating evidence “as to any matter relevant to the sentence ... regardless of its admissibility under the rules governing admission of evidence at criminal trials.” Id. § 3593(c). Whereas Runyon may wish to severely cabin the jury’s sentencing discretion by restricting the evidence it may hear and the inferences it may draw, the FDPA anticipates that the jury will confront a broad array of information and enjoy considerable leeway in assessing it. Third, as envisioned by the FDPA, capital sentencing proceedings are not only wide-ranging; they are in important respects even-handed. Just as the defendant may introduce evidence on myriad mitigating factors, so the prosecution may try to prove an equally varied range of aggravating factors. Id. § 3592(a), (c). Runyon, by contrast, seems to contemplate a more one-sided affair, with the defendant making his mitigation case more or less unfettered and the prosecution responding with but a narrow subset of the available aggravating evidence. Though we must uphold for capital defendants the procedural safeguards guaranteed them by the Constitution and the FDPA, we must also avoid constraining unduly the prosecution’s ability to paint a complete picture of the defendant’s crime and character, lest the jury be less than fully and amply informed. With these caveats in mind, we now turn to Runyon’s specific challenges. IV. Runyon first challenges the nonstatuto-ry aggravating factors submitted to the jury and the prosecution’s efforts to prove them. Specifically, pursuant to the FDPA, 18 U.S.C. § 3592(c), the prosecution gave notice of four nonstatutory aggravating factors for the jury to consider: (1) lack of remorse; (2) injury and loss to Voss and his family and friends (“victim impact”); (3) use of law enforcement and military training to perpetrate the murder; and (4) history of physical abuse toward women. Runyon objected on various grounds to each of these factors, as well as to some of the evidence and arguments the prosecution presented to establish them. The district court overruled his objections, and the jury heard evidence on all four, ultimately finding all of them to exist. We consider each factor in turn. A. We first address Runyon’s arguments on the lack-of-remorse aggravator. While Runyon does not challenge on appeal the propriety of the prosecution proposing this aggravator, he contends that the court’s decision to admit a particular piece of evidence in support of this factor (and in rebuttal to a mitigator proposed by the defense) violated the Constitution and the FDPA. That evidence was a videotaped depiction of Runyon being interrogated on December 11, 2007, as the investigation came closer to uncovering his role in the crime. The video runs just over forty-two minutes. It shows three law enforcement officers, led by Detective Larry Rilee of the Newport News Police Department, questioning Runyon intensively about his role in Voss’s death. The interrogation begins with Rilee reading Runyon his Miranda rights, which Runyon confirms understanding. Runyon makes a handful of in-culpatory statements — including admitting that he knew Draven somewhat, had spoken with Cat by phone, owned the map with notes about Voss, and had been in possession of both the photo of Cat and Draven and certain firearms. Nevertheless, he sits silently for the vast majority of the exchange, seldom providing answers longer than one or two words, and he never expressly admits any involvement in the murder. At one point, the officers leave the room, apparently to give Runyon time to consider whether he wants to cooperate with the investigation. (While the time stamp indicates that Runyon remained alone for approximately twelve minutes, the video omits this period.) Throughout the interrogation, Runyon’s demeanor is basically attentive; his tone is generally calm; and his face is largely expressionless. The conversation ends when Runyon makes clear that he wishes to consult with counsel. The video was played before the jury and subsequently admitted into evidence during the portion of the penalty selection phase in which the prosecution had the opportunity to rebut mitigation evidence presented by the defense. Specifically, the prosecution proposed to use the video to rebut evidence on the statutory mitigator that “[a]nother defendant or defendants, equally culpable in the crime, will not be punished by death.” 18 U.S.C. § 3592(a)(4). On this factor, the defense had introduced Cat’s plea agreement and the accompanying statement of facts. In response, the prosecution sought to have Rilee testify about Cat’s and Draven’s post-arrest confessions, contrasted with the video and Rilee’s recollections of Runyon’s December 11, 2007, interrogation. Defense counsel objected orally, arguing that the video did not properly rebut any defense evidence. The district court overruled the objection. As for the equally-eulpable mitigator, the court held that the prosecution was entitled to explain why the government had not pursued the death penalty against Runyon’s co-conspirators. Moreover, the court expressed an expectation that the video would also provide evidence supporting the lack-of-remorse ag-gravator. 1. On appeal, Runyon renews his objection to this piece of evidence on multiple grounds — some constitutional, some statutory. We first address Runyon’s contention that several statements made by the interrogating officers in the video contaminated the sentencing proceeding with invidious considerations concerning his ethnicity and religion. Toward the beginning of the exchange, Detective Rilee asked Runyon: “[Yjou’re Asian, right, Asian-American? You’re an honorable Asian man, aren’t you?” ‘Yes sir,” he answered. Imploring Runyon to be honest, Rilee continued, ‘You know, if you’re an honorable Asian man and your integrity is intact and you have any respect for anybody at all, then you’ll do the right thing today, okay?” The officers proceeded to invoke Runyon’s “honor” on multiple occasions during the interrogation. Later, Rilee asked Runyon whether he had any “religious beliefs,” to which Runyon replied that he is a Christian. Rilee continued: You believe in forgiveness then; you can be forgiven for whatever the sin might be. Obviously in the Ten Commandments, “thou shalt not kill” would be one of the more prominent ones. But do you believe that you can be forgiven for that? ... If you asked God for forgiveness, do you believe that He’ll forgive you for that? You can repent your sins, can’t you? ‘Yes, yes, anybody can repent their sins,” Runyon stated. Rilee responded, “Having that in mind, you know, don’t you think it’s time to repent, to say that you’re sorry for what happened ... ?” Runyon answered, “It sounds like to me that I need a lawyer,” at which point the interrogation effectively ended. Runyon further argues that several additional portions of the video were likewise improperly inflammatory. Whatever the force of those arguments might be, this court need proceed no further than the officers’ comments referencing Runyon’s ethnicity and religion to conclude that the video had no place at this sentencing proceeding. The government contends that these comments were not problematic because, first, they “were not addressed to the jury” but were instead “intended to elicit truthful information from [the] defendant” and, second, they “appealed not to negative aspects of Runyon’s character, but to positive aspects of his identity.” Appellee’s Br. 33. For the reasons that follow, we find these arguments unpersuasive. The Supreme Court has long made clear that statements that are capable of inflaming jurors’ racial or ethnic prejudices “degrade the administration of justice.” Battle v. United States, 209 U.S. 36, 39, 28 S.Ct. 422, 52 L.Ed. 670 (1908). Where such references are legally irrelevant, they violate a defendant’s rights to due process and equal protection of the laws — whether the remarks occur during the prosecution’s presentation of evidence or argumentation. See, e.g., Bains v. Cambra, 204 F.3d 964, 974 (9th Cir.2000); United States v. Vue, 13 F.3d 1206, 1212-13 (8th Cir.1994); United States v. Doe, 903 F.2d 16, 24-25 (D.C.Cir.1990); see also McCleskey v. Kemp, 481 U.S. 279, 309 & n. 30, 107 S.Ct. 1756, 95 L.Ed.2d 262 (1987). And the Supreme Court has taken pains to ensure that racial prejudice plays no role in jury deliberations in capital sentencing proceedings. See, e.g., Turner v. Murray, 476 U.S. 28, 36-37, 106 S.Ct. 1683, 90 L.Ed.2d 27 (1986) (holding that “a capital defendant accused of an interracial crime is entitled to have prospective jurors ... questioned on the issue of racial bias”). While it is certainly true that district judges must weigh the “probative value” of evidence against “the danger of creating unfair prejudice” in each case under the FDPA, 18 U.S.C. § 3593(c), we think that the particular references to ethnicity here were problematic for several reasons. One, the references came directly from the mouths of law enforcement. Two, they directly alluded to the defendant himself. Three, they bore no relevance to the particular issues that the jury was being asked to resolve. And four, they conveyed what were, frankly, stereotyping and insulting notions about how “an honorable Asian man” is supposed to act. Thus, while it is admittedly impossible to script all-or-nothing answers to evidentiary questions on appeal, the error in admitting the statements at issue here is apparent. We are compelled to reach the same conclusion with respect to the discussion of Runyon’s religion. The Supreme Court has held that the First Amendment “prevents [the prosecution] from employing evidence of a defendant’s abstract beliefs at a sentencing hearing when those beliefs have no bearing on the issue being tried.” Dawson v. Delaware, 503 U.S. 159, 168, 112 S.Ct. 1093, 117 L.Ed.2d 309 (1992). Here, the government makes no argument that the video’s references to Runyon’s faith were germane to the question of what sentence he should receive, nor is any such argument apparent to the court. There is no indication that the killing was motivated by or connected to Runyon’s Christianity at all, and the discussion of his religion did not serve to rebut any mitigating evidence offered by the defense. See id. at 166-68, 112 S.Ct. 1093. Like Runyon’s ethnic background, neither his Christian beliefs nor the implication that he somehow betrayed those beliefs by failing to “repent his sins” was legally relevant in any way. Likewise, this exchange was flawed for evidentiary purposes because the offending statements were made by law enforcement officers and were personally targeted at the defendant. It was accordingly error for the jury to hear these remarks. As mentioned above, Runyon further contends that a number of other comments made by the officers in the video were improperly inflammatory. These involve statements in which the officers expressed opinions about the crime, Runyon himself, and how a jury might ultimately decide his fate — including statements implying that Runyon’s refusal to confess might render him subject to capital punishment: • “But don’t let me walk out of that, that door right there thinking that you’re some piece of shit that murdered a U.S. naval officer and didn’t have enough respect to man up when he— when it was done.” • “He didn’t deserve to die like a dog.” • “I don’t have any disrespect for you at this point, but if you don’t have enough integrity, enough honor about yourself to tell the truth at this point, then I won’t have any respect for you. And as a matter of fact, when they make a choice as to whether they charge you with capital murder and seek the death penalty, I’ll remember exactly how honorable you were, or not....” • “It makes a difference in the way that the jury is gonna perceive you when you go to trial. It’s either gonna be, “well this is a cold-blooded murderer’ or ‘this is a guy who made a mistake.’ ... [T]hat’s what they’re going to think about when they’re deciding how this can end up for you.” • “But I want you to sit back and I want you to think about, in front of a jury of twelve, twelve citizens, okay? About this family right here, this whole family is torn apart.... And David Runyon is going to be the one that did that — that physically did it. Without David Runyon’s cooperation, without David Runyon’s honesty and remorse for what he did, what do you think twelve reasonable people would, uh, conclude from that? ... [Tjhey’re going to make you out to be a monster, man.” Runyon claims that the jury’s consideration of these statements offended the Eighth Amendment by inviting application of the death penalty in an arbitrary and capricious manner under precedent stemming from Furman v. Georgia, 408 U.S. 238, 92 S.Ct. 2726, 33 L.Ed.2d 346 (1972). Moreover, he offers additional arguments as to why introduction of the interrogation video was erroneous. First, he contends that the video was inadmissible on the lack-of-remorse aggravator because it did not actually provide any evidence relevant to the issue of remorse. He further argues that the video was irrelevant to rebutting the equally-culpable mitigator because evidence of conduct after the crime is immaterial to a defendant’s culpability “in the crime,” per the text of the FDPA. 18 U.S.C. § 3592(a)(4) (emphasis added). Next, Runyon asserts that he sufficiently invoked his Fifth Amendment right to remain silent during the interrogation and that introduction of the video therefore violated the principles set forth in Miranda v. Arizona, 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694 (1966), and its progeny. And finally, he contends that even if some portions of the video were pertinent to certain questions before the court, its admission as a whole was nevertheless unfairly prejudicial under the FDPA. In response to Runyon’s Eighth Amendment argument concerning inflammatory statements made by the officers, the government contends that “statements by detectives, made in the course of the investigation, and not referred to by the prosecutor, cannot be attributed to the government deliberately introducing prejudicial or arbitrary matters.” Appellee’s Br. 36. As for Runyon’s other claims, the government first responds that the video was admissible as to the lack-of-remorse aggravator because Runyon’s refusal during the interrogation to take responsibility for his actions, along with his general demeanor when faced with the officers’ questions, conveyed a complete absence of contrition. And with regard to the video’s relevance to the equally-culpable miti-gator, the government contends that culpability is a continuing moral concept that does not simply shut off once a crime has been committed. Further, in response to Runyon’s Fifth Amendment self-incrimination claim, the government argues that evidence of a defendant’s demeanor while sitting silent is meaningfully distinct from evidence of silence itself and, in any event, that Runyon never unambiguously invoked the right to remain silent after receiving Miranda warnings, as required by Berghuis v. Thompkins, - U.S. -, 130 S.Ct. 2250, 176 L.Ed.2d 1098 (2010). And finally, for all of these reasons, the government rejects the defense’s argument that admission of the video unduly prejudiced Runyon. The parties proceed to argue at some length over these additional claims of error pertaining to the video. Nevertheless, because we have established that the court erred in admitting the video due to the particular references to ethnicity and religion described above, we need not consider what other reasons may or may not exist for coming to the same conclusion. To be sure, one could argue that the trial court’s error extends only to any offending portions of the video. In the interest of caution, however, we will assume that exclusion of the entire video was warranted. Moreover, as discussed in greater detail below, we shall elect to apply the most defendant-favorable standard possible in order to determine whether this error requires reversal of Runyon’s sentences. 2. The parties vigorously dispute the proper standard for deciding whether Runyon’s sentences must be reversed on account of the erroneous admission of the interrogation video. The defense asserts that because certain of Runyon’s arguments are constitutional in nature, the government must “prove beyond a reasonable doubt that the error complained of did not contribute to the verdict obtained.” Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967). The government, in contrast, contends that Runyon did not properly preserve his constitutional arguments before the district court and that plain error analysis pursuant to United States v. Olano, 507 U.S. 725, 113 S.Ct. 1770, 123 L.Ed.2d 508 (1993), thus applies. We note that although Runyon’s counsel did object strenuously to the introduction of the video below, the argument was premised predominantly, even exclusively, on the notion that the video did not properly rebut the defense’s evidence on the equally-culpable mitigator for several statutory and evidentiary reasons. Nevertheless, because we find for the following reasons that admission of the interrogation video constituted harmless error even under the most stringent of standards, we proceed pursuant to Chapman. See United States v. Williams, 461 F.3d 441, 448 (4th Cir.2006) (electing to apply Chapman where not necessarily required). As a threshold matter, the fact that the district court provided a detailed limiting instruction specifically circumscribing the jury’s consideration of the interrogation video is significant. The court stated: During the government’s rebuttal evidence, it played for you a videotape of an interrogation of the defendant, David Anthony Runyon. This evidence was offered for the limited purposes of demonstration of remorse in regard to the alleged nonstatutory aggravating factor to this effect, and for relevant culpability in regard to the alleged statutory mitigation factor to this effect. You are instructed that no statement made by the detectives during the interrogation is itself evidence in this case. You should disregard any statements of fact or opinion made by the interrogating officers, including any speculation about a future jury’s possible sentencing decision or the punishment that the defendant might receive, or any characterization by the officers of the defendant’s conduct or character. These portions of the video could not be removed without making the interrogation itself unintelligible, but they should not be considered by you in deciding on defendant’s sentence. In addition, in accordance with the directive stated in 18 U.S.C. § 3593(f), the court delivered the following more general — but equally unequivocal — instruction establishing the impropriety of considering Runyon’s ethnicity or religious affiliation: In considering whether a death sentence is justified, you must not consider the race, color, religious beliefs, national origin, or sex of the defendant or the victim in this case. These facts are completely irrelevant to the important issues you must consider at this phase of the proceedings. You are not to recommend a sentence of death unless you have concluded that you would recommend a sentence of death for the crime in question no matter what the race, color, religious beliefs, national origin, or sex of either the defendant or the victim might have been. To emphasize the importance of this consideration, the special verdict form has a certificate that must be signed by each juror. When you have reached a decision, each of you is to sign the certificate, but only if this is so, attesting that considerations of race, color, religious beliefs, national origin, or sex of the defendant or the victim w[ere] not involved in reaching your individual decision, and attesting that you would have made the same recommendation regarding a sentence for the crime in question no matter what the race, color, religious beliefs, national origin, or sex of the defendant or victim might have been. Each juror signed the certificate. Our analysis is governed, first and foremost, by the “almost invariable assumption of the law that jurors follow their instructions.” Richardson v. Marsh, 481 U.S. 200, 206, 107 S.Ct. 1702, 95 L.Ed.2d 176 (1987). The assumption would certainly apply in a case such as this one, where a certificate was signed and where the limiting instructions were so clear and emphatic. The assumption has become axiomatic because it is so essential to the efficient functioning of the criminal justice system. “Not every admission of inadmissible ... evidence can be considered to be reversible error unavoidable through limiting instructions; instances occur in almost every trial where inadmissible evidence creeps in, usually inadvertently.” Bruton v. United States, 391 U.S. 123, 135, 88 S.Ct. 1620, 20 L.Ed.2d 476 (1968). Accordingly, absent some specific “reason to doubt that the jury ... adhered to the district court’s directive,” this court will not conclude to the contrary. United States v. Castillo-Pena, 674 F.3d 318, 322 (4th Cir.2012). We see no such reason here. Nevertheless, we note that whereas the district court’s instructions are naturally read to neutralize the officers’ statements in the video, Runyon’s challenge goes further. Specifically, Runyon objects to admission of the video in its entirety — including his responses, verbal and nonverbal alike, to the officer’s questions. We therefore consider, and find convincing, additional grounds establishing the harmlessness of introducing the video at all, focusing in particular on the limited purposes for which the court permitted the jury to consider it: the lack-of-remorse aggravator and the equally-culpable mitigator. The government has demonstrated beyond a reasonable doubt that the jury would not have voted any differently on the lack-of-remorse aggravator in the absence of the interrogation video. The prosecution’s argument that Runyon exhibited no remorse for killing Voss rested on evidence of at least four classes of affirmative conduct and speech on Runyon’s part, none of which depended on the video for proof. Runyon (1) bragged about being a hitman to at least three people following the shooting; (2) attempted to collect on the contract after the murder; (3) schemed for months to conceal evidence and mislead law enforcement officers about his role in the conspiracy; and (4) groused crudely about the investigation in recorded phone calls — including describing the accumulated evidence as “circumstantial bullshit” and declaring that “[i]f they don’t watch themselves before it’s all said and done they’re gonna have a fucking civil lawsuit for harassment.” By contrast, the defense never attempted to argue that Runyon exhibited remorse in any way. Hence, we find that “[e]ven without considering [the tainted evidence], the jury could not reasonably have reached another conclusion regarding lack of remorse.” United States v. Caro, 597 F.3d 608, 631 (4th Cir.2010). We are likewise convinced beyond a reasonable doubt that introduction of the interrogation video was harmless with respect to the equally-culpable miti-gator — namely, that “[a]nother defendant or defendants, equally culpable in the crime, will not be punished by death.” 18 U.S.C. § 3592(a)(4). The fact that the jury accepted the defense’s arguments on this factor, unanimously finding in Runyon’s favor, is dispositive. Hence, this evidence did not detract from Runyon’s defense. Introduction of the video, therefore, neither encouraged the jury to find any inadequately supported aggravator nor discouraged the jury from finding any adequately supported mitigator, leaving the slate of factors in the aggravator-ver-sus-mitigator computation required by the FDPA unaltered. Nor do we believe that the overall balancing of these factors could have possibly produced a different result. The Chapman standard requires review of “the record as a whole to determine the probable impact of the improper evidence on the jury.” Williams, 461 F.3d at 448-49 (emphasis added) (internal quotation marks omitted). Thus, erroneously admitted evidence cannot be assessed in isolation. Viewed quantitatively, the interrogation video comprised an insignificant portion of the proceeding, consuming less than an hour of a combined trial and sentencing lasting longer than three weeks and featuring five days of evidence and thirty-seven witnesses during the sentencing portion alone. See United States v. Stitt, 250 F.3d 878, 898 (4th Cir.2001) (finding admission of improper evidence harmless in death penalty case where such evidence “comprised only a fraction of the total testimony heard during the penalty phase”). The video was likewise inconsequential from a qualitative perspective. What ultimately drove the jury’s decision was not some video but the overpowering evidence of Runyon’s guilt, his pivotal role in the crime, and the exceptionally callous nature of his conduct. With three fatal shots to the chest and abdomen, Runyon robbed an innocent man of his life and two small children of their father. And for what? Money. The aggravating factors found by the jury — including that Runyon sought pecuniary gain, engaged in substantial planning and premeditation, and utilized his military and criminal justice background to facilitate his actions — reflect the utter heartlessness of this horrific homicide, providing an abundant basis for the verdict. See Stitt, 250 F.3d at 898-99 (finding error harmless in light of “the overwhelming force of the aggravating factors found by the jury which showed the violent and predatory nature of [the defendant’s] character and activities”). Moreover, even beyond the equally-culpable mitigator, Runyon’s counsel had the opportunity — entirely untainted by the interrogation video — to present a multitude of arguments for leniency. Specifically, the defense proposed fourteen mitigating factors and offered testimony from nearly two dozen witnesses during the penalty selection phase alone, all in hopes of dissuading the jury from recommending the death penalty. The defense’s evidence ranged from Runyon’s childhood and character to his relationships and employment history-and even to his pre-trial conduct in jail and ability to adjust to prison in the event he received a life sentence. Nevertheless, although the jury did find several mitigators in Runyon’s favor, the case for clemency simply did not overcome in the jury’s eyes the case presented by the government. We recognize, of course, that where “record review leaves the conscientious judge in grave doubt about the likely effect of an error,” the error should be treated “as if it affected the verdict.” O’Neal v. McAninch, 513 U.S. 432, 435, 115 S.Ct. 992, 130 L.Ed.2d 947 (1995). But we have no doubt that the error in admitting the interrogation video “did not contribute to the verdict obtained,” Chapman, 386 U.S. at 24, 87 S.Ct. 824, and that reversal is consequently unwarranted. B. A second nonstatutory aggravating factor charged that Runyon “caused injury, harm and loss to the victim and the victim’s family and friends.” To prove this factor, the prosecution introduced various items of “victim impact” evidence. These included the testimony of Jennifer Kime, a former Navy officer, and Lieutenant Jeremy Chayer, both of whom served with Voss on the USS Elrod, as well as a video and an approximately nine-minute montage of photographs of Voss, both of which were shown during his memorial service aboard the Elrod. Kime and Chayer testified about their friendships with Voss, his Navy service, and the impact of his death on them and on the Elrod’s crew more generally, while the video contained statements by Chayer and Commander Matthew Graham reminiscing about Voss. Runyon objected below, and argues on appeal, that this aggravator violated both the Constitution and the FDPA insofar as it included (1) the impact of Voss’s death on his friends and colleagues, rather than just his family, and (2) Voss’s professional contributions as a Navy officer, rather than just his personal relationships with specific individuals. We consider Runyon’s constitutional and statutory challenges to the factor de novo and review the district court’s decision to admit certain evidence on that factor for abuse of discretion. United States v. Higgs, 353 F.3d 281, 320, 322 (4th Cir.2003). 1. Runyon first contends that both the Eighth Amendment and the FDPA limit the scope of victim-impact evidence in a capital sentencing proceeding to the impact of the crime on the victim’s family and that the nonstatutory aggravating factor transgressed these limits by bringing before the jury the impact of Voss’s death on his Mends and shipmates. Neither the constitutional nor the statutory argument succeeds. Runyon’s constitutional argument relies on the Supreme Court’s decision in Payne v. Tennessee, 501 U.S. 808, 111 S.Ct. 2597, 115 L.Ed.2d 720 (1991). In holding that the introduction of victim-impact evidence during capital sentencing did not necessarily violate the Eighth Amendment, the Payne Court understood such evidence to include “evidence about the victim and about the impact of the murder on the victim’s family.” 501 U.S. at 827, 111 S.Ct. 2597. Runyon takes this statement for an exhaustive definition, one that implicitly prohibits the introduction of evidence concerning the impact of the victim’s death on any individuals other than “the victim’s family.” Runyon’s reading, however, is a stretch. As even he concedes, “certain language used by the majority ... opinion[ ] could be read as suggesting approval of a broader range of evidence.” Appellant’s Opening Br. 66. Indeed, on multiple occasions, the Payne Court expressly countenanced the introduction of evidence concerning the impact of the victim’s death on society at large. See, e.g., id. at 822, 111 S.Ct. 2597 (noting that the prosecution should be permitted to “demonstrate] the loss to the victim’s family and to society which has resulted from the defendant’s homicide” (emphasis added)); id. at 825, 111 S.Ct. 2597 (“[T]he State has a legitimate interest in counteracting the mitigating evidence which the defendant is entitled to put in, by reminding the sentencer that just as the murderer should be considered as an individual, so too the victim is an individual whose death represents a unique loss to society and in particular to his family.” (emphasis added) (internal quotation marks omitted) (quoting Booth v. Maryland, 482 U.S. 496, 517, 107 S.Ct. 2529, 96 L.Ed.2d 440 (1987) (White, J., dissenting))). In light of these statements, we see no reason to think that the Payne Court intended to forbid the introduction of evidence regarding the impact of the victim’s death on his friends and colleagues as well as his family. For limiting victim-impact evidence to family would be an exceedingly artificial line to draw. While the most devastating sense of loss from a murder may well be felt by immediate family, the deceased’s Mends and colleagues may suffer too. Just as individuals may touch many people during life, so too may their death be widely mourned. It was thus well within the district court’s discretion to admit the expressions of grief felt by Voss’s shipmates for the loss of one of their own. Kime, for instance, testified that “[everybody [aboard the Elrod] was shocked, and everybody was upset,” while Chayer similarly reported that “[e]veryone on board, from the captain all the way down to the new seaman recruit that checked in the day before, loved him.” In reading Payne to allow such evidence, we are in good company. See, e.g., United States v. Whitten, 610 F.3d 168, 187-88 (2d Cir.2010); United States v. Bolden, 545 F.3d 609, 626 (8th Cir.2008); United States v. Barrett, 496 F.3d 1079, 1098 (10th Cir.2007); United States v. Bernard, 299 F.3d 467, 478 (5th Cir.2002). Runyon’s statutory argument is equally strained. Echoing his constitutional argument, Runyon emphasizes the provision of the FDPA providing that non-statutory aggravating factors may include factors concerning the effect of the offense on the victim and the victim’s family, and may include oral testimony, a victim impact statement that identifies the victim of the offense and the extent and scope of the injury and loss suffered by the victim and the victim’s family, and any other relevant information. 18 U.S.C. § 3593(a)(2) (emphases added). Once again, Runyon takes the references to “the victim’s family” to preclude evidence regarding the impact of the victim’s death on his friends and colleagues. But once again, Runyon is creating restrictions on victim-impact evidence out of whole cloth. Contra Runyon’s interpretation, the text of this provision is illustrative rather than exhaustive, identifying some kinds of aggravating factors and evidence that the prosecution’s notice to the defendant “may include” and concluding with a catchall permitting the prosecution to present “any other relevant information.” Runyon’s narrower reading, moreover, is in tension with the provision of the FDPA permitting the jury to “consider whether any other aggravating factor for which notice has been given exists.” Id. § 3592(c) (emphasis added). Based on the broad language of the provision cited by Runyon, other circuits have consistently construed the FDPA to allow the prosecution to introduce evidence concerning the impact of the victim’s death on individuals outside his family. See, e.g., Whitten, 610 F.3d at 188-89; Bolden, 545 F.3d at 626; Barrett, 496 F.3d at 1098-99. We see no reason to hold otherwise. 2. Runyon also challenges the victim-impact aggravator on the ground that some of the evidence introduced to support it concerned Voss’s professional accomplishments as a Navy officer, rather than being limited to his relationships with specific individuals (family members or otherwise). Both Kime and Chayer, for instance, testified about Voss’s position and duties aboard the Elrod — testimony that, according to Runyon, exceeded constitutional and statutory limits on victim-impact evidence. These putative limits, however, lack a sound legal basis. On the contrary, Payne expressly allowed the prosecution to provide “a quick glimpse of the life” of the victim and his “uniqueness as an individual human being,” 501 U.S. at 822, 823, 111 S.Ct. 2597, and nothing in the FDPA purports to restrict this use of victim-impact evidence. Other circuits have accordingly upheld the introduction of evidence regarding the victim’s professional background and accomplishments. See, e.g., Whitten, 610 F.3d at 189; Barrett, 496 F.3d at 1099; Bernard, 299 F.3d at 479. And for good reason. As the Payne Court explained, to forbid the prosecution to give the jury a sense of the victim’s background would be to “unfairly weight[ ] the scales in a capital trial,” given that “virtually no limits are placed on the relevant mitigating evidence a capital defendant may introduce concerning his own circumstances.” 501 U.S. at 822, 111 S.Ct. 2597. We would countenance such unfairness here were we to declare the evidence concerning Voss’s Navy service inadmissible. The prosecution’s aggravation case was already less extensive than the defense’s mitigation case. To take just one measure: whereas the prosecution called only fourteen direct and two rebuttal witnesses during the penalty selection phase, the defense called twenty-one mitigation witnesses. The district court was well within its discretion in seeking to ensure some sense of balance in the parties’ presentations. The evidence concerning Voss’s Navy service did nothing more than help to provide “a quick glimpse” of the central aspect of his professional life — and thus accorded with both the Eighth Amendment and the FDPA. C. A third nonstatutory aggravating factor charged that Runyon “utilized education, training and experience that he received in college courses focused on criminal justice, as a law enforcement and correctional officer, as an officer of the Kansas National Guard and as a member of the United States Army to kill Cory Voss.” The prosecution sought to prove this factor by introducing evidence that Runyon had attended a Junior ROTC military academy; served as an officer in the Kansas National Guard; completed courses in crimin