A jury convicted appellant Ricardo Jones of first-degree murder while armed and four weapons charges related to his shooting of David Valentine. He was also convicted of escape. Appellant primarily objects to the trial court’s rulings admitting other crimes evidence and expert testimony on firearm and toolmark identification. He also argues that the trial court impermissibly restricted bias cross-examination of two government witnesses. Finding no reversible error on these or the other grounds raised, we affirm.
*1134I. Factual Background
Around noon on July 6, 2005, Edward Davis and his friend David Valentine were walking in their neighborhood, on the 1200 block of Meigs Place, N.E., in the section of the city known as “Trinidad.” When they passed Joseph Leaks, a man Mr. Davis had seen in the area several times before, Davis said hello. Without warning, Mr. Leaks turned around and pulled out a handgun. Leaks apologized right away and explained that he “thought [they were] somebody else.” Davis and Valentine ignored the apology and continued up the street.
Shortly thereafter, Davis and Valentine walked back down the block. Davis noticed Leaks and appellant (whom Davis had never seen before) standing near Leaks’s apartment building. Davis testified that, because Leaks had just brandished a pistol at him, he paid close attention to both men as he and Valentine neared them. According to Davis, Leaks was skinny, over six feet tall, had a shaved head, and wore glasses. On the other hand, Leaks’s friend (appellant Jones) was approximately 5'8", with a medium build, and a “strong face.”
When Davis and Valentine were about arm’s reach away from Leaks and Jones, Leaks attempted to apologize again. Davis ignored Leaks’s apology, but Valentine said he would not accept it and asserted, “that wasn’t the last gun they made when you got yours.” Suddenly, Davis heard “something go bang.” Valentine grabbed his chest and said, “you going to shoot me[?] Your man pulled a pistol on me. You’re going to shoot me?” Appellant Jones was the only person with a gun out and was “still pointing” it at Valentine as Valentine collapsed to the ground. Jones then stood over the victim and dared him to “say something else[.]” Davis later picked appellant’s picture out of a photo array. He also identified appellant at trial.
Immediately after hearing the shot, Roderick Powell, who lived nearby, came outside. He saw a man in the street place a dark object into his waistband. Another man, whom Mr. Powell recognized as one of his neighbors (Leaks), then joined the person with the dark object, and they sped away in Leaks’s gray station wagon.
After the shooting, Leaks and Jones went to North Carolina, and they often stayed with Amanda Ward in Reidsville, North Carolina. On August 5, 2005, Jones and Leaks robbed a Check Into Cash store in nearby Greensboro. They shot the security guard as soon as they entered the store, but the guard survived. Store manager Kim Geil testified that each robber carried a pistol and covered his face with black nylons and sunglasses. After collecting money, the men took the security guard’s .38 caliber pistol and ran out of the store.
Police soon arrested appellant and Leaks. When Ms. Ward learned of the arrests, she checked her guest room and discovered a bag of live ammunition underneath the bed. Soon thereafter, she found in a vent two socks containing a .45-caliber pistol and a 9-millimeter pistol. (While searching Leaks’s home on Meigs Place in July, police had recovered several 9-mil-limeter cartridges, but they found no .45 caliber ammunition.)
Appellant and Devone Hines occupied the same cell for several weeks. During that time, appellant told Mr. Hines that he had shot and killed a man with a .45-caliber pistol over the July 4th weekend in the District’s Trinidad neighborhood. At trial, Hines recounted how appellant told him about the verbal exchange between Leaks and Valentine prior to the shooting and how appellant stood over the victim *1135and said something to him afterwards. Appellant told Hines that he and Leaks later went to Greensboro, North Carolina, and robbed a check-cashing store. They shot the store’s security guard and took his .38-caliber pistol. Appellant mentioned that he again used the .45-caliber pistol and Leaks was armed with a 9-millimeter pistol. Because Jones was not certain he had wiped his fingerprints from the guns, he asked Hines to retrieve them from a vent in North Carolina once Hines was released.
Instead of proceeding to trial, on April 3, 2007, Leaks pleaded guilty to a five-count criminal information that charged escape, obstruction of justice, accessory after the fact to an assault with intent to kill while armed, possession of a firearm during a crime of violence, and second-degree child sexual abuse (for his sexual relationship with a fourteen-year-old girl). Leaks did not testify at Jones’s trial.
II. Firearms and Toolmark Identification Evidence
A. Background
When Mobile Crime Technician Gerald Wills arrived at the 1200 block of Meigs Place, N.E., paramedics had already rushed Valentine to the hospital, where he later died of the gunshot wound to his chest. Mr. Wills recovered a .45-caliber shell casing and a copper-jacketed bullet from the murder scene. Crime scene investigators in North Carolina recovered a .45-caliber shell casing and bullet as well as a 9-millimeter casing and bullet from the Check Into Cash store.
Using the traditional method of pattern matching, two firearms experts examined this evidence.1 Neal Morin compared the bullets and shell casings recovered from the North Carolina crime scene to bullets and casings test-fired from the pistols found in Ms. Ward’s spare room. Mr. Morin testified that the .45-caliber shell casing and bullet were fired from the .45-caliber pistol he test-fired. His “level of certainty with respect to that conclusion” was 100% or “to the exclusion of all other firearmsf.]” Defense counsel did not object to these questions, nor did he move to strike the answers.
Examiner Michael Mulderig used the same methodology and testified that the .45-caliber shell casing and bullet from the District of Columbia crime scene were fired from the same .45-ealiber pistol recovered from Ward’s home. Like Morin, Mulderig answered “yes” when the prosecutor inquired whether his conclusion regarding the match was “to the exclusion of all other firearms?” When the prosecutor asked Mulderig about his “level of certainty with respect to” his conclusion, defense counsel interjected: “Objection. Foundation.” Judge Dixon overruled the objec*1136tion and Mulderig stated he was 100% certain about the match.
Defense counsel retained a firearms expert, who independently examined the same evidence. That expert did not testify at trial.
B. The Request for a Frye Hearing
Just prior to trial, in January of 2008, appellant’s counsel orally requested leave to adopt a motion which former co-defendant Leaks had filed in September of 2006 seeking a pretrial hearing on the admissibility of firearms identification evidence. Judge Dixon allowed the defense to adopt, summarize, and argue the motion. Appellant’s counsel urged the court to conduct a Frye hearing,2 asserting that pattern matching “is not generally accepted within the scientific community.” Judge Dixon advised, “I’m familiar with that type of testimony, because we have heard it in other cases. What is the novelty of this issue[?]” Counsel argued that there is: a lack of “objective criteria by which a firearms examiner makes his conclusions”; “no peer review of their work”; “no proficiency testing”; and “no calculation of error rates[J” By contrast, the prosecutor argued that pattern matching is the “generally accepted practice and, therefore, presumptively reliable.” Judge Dixon agreed that the evidence was “an accepted type of analysis that has been admitted in courtroom after courtroom[,]” and he did not “find any need to conduct any type of pretrial hearing on [its] admissibility^]” Jones contends that the trial court erred in denying this request for a Frye hearing.3
1. The Frye Standard
In the District of Columbia, “before expert testimony about a new scientific principle [may] be admitted, the testing methodology must have become ‘sufficiently established to have gained general acceptance in the particular field in which it belongs.’ ” Williams v. District of Columbia, 558 A.2d 344, 346 (D.C.1989) (quoting Frye, 54 App.D.C. at 47, 293 F. at 1014). The “issue is consensus versus controversy over a particular technique, not its validity.” United States v. Jenkins, 887 A.2d 1013, 1022 (D.C.2005) (citing United States v. Porter, 618 A.2d 629, 633 (D.C.1992)). Moreover, general acceptance does not require unanimous approval. Porter, 618 A.2d at 634. Once a “technique has gained such general acceptance, we will accept it as presumptively reliable and thus generally admissible into evidence. The party opposing the evidence, of course, may challenge the weight the jury ought to give it.” Jones v. United States, 548 A.2d 35, 39 (D.C.1988). Although we do not doubt that a technique that has previously been recognized in court as generally accepted may lose that wide acceptance, we conclude that appellant has not shown that to be the case with respect to pattern matching as a way of identifying firearms.4
*11372. Was a Frye Hearing Required?
Here, the trial court properly admitted the expert testimony without conducting a Frye hearing. Frye only applies to “a novel scientific test or a unique controversial methodology or technique.” Drevenak v. Abendschein, 773 A.2d 396, 418 (D.C.2001); see Cook v. Edgewood Mgmt. Corp., 825 A.2d 939, 950-51 (D.C.2003) (“Frye [ ] is inapplicable” and there is “no burden ‘to demonstrate ... [that the cobalt test] has been generally accepted in the relevant scientific community’ ” because testimony of two investigators “highlights the fact that the MPD had used the cobalt test for many years” and nothing suggested it was “a novel test,” or “new scientific technique,” or “unique controversial methodology!.]”) (quoting Porter, 618 A.2d at 633). Pattern matching is not new, and courts in this jurisdiction have long been admitting firearms identifications based on this method.5 Even Leaks’s motion conceded that “firearm and toolmark identification evidence has generally historically been accepted in various courts across the country.” Indeed, Leaks (and appellant) cited no case that had excluded such evidence.
Appellant attempts to avoid this problem by asserting that, had the trial court conducted a Frye hearing, the defense could have demonstrated that the challenged method “was no longer generally accepted in the scientific community.” This assertion is simply not true; comparison matching remains widely accepted and appellant misplaces his reliance upon a law review article6 to suggest that pattern matching is no longer generally accepted within the relevant scientific community. Even the courts that have held pretrial hearings on the admissibility of firearms identification evidence, and considered the studies and articles cited by Jones on appeal (and Leaks below),7 have not excluded this type of proof. Instead, the most these courts have done is to impose guidelines for the presentation of such evidence.8
*1138In sum, nothing presented to the trial court (or to us) suggests that the pattern matching methodology is no longer generally accepted,9 and there was no need for Judge Dixon to expend scarce judicial resources on a Frye hearing.10 See Jones, 548 A.2d at 40, 42 (“General acceptance means just that; the answer cannot vary from case to case.... [So in evaluating general acceptance,] judicial notice of court opinions and scientific literature is appropriate and, on occasion, even necessary.”).
C. The Experts’ Expressions of Certainty
Appellant asserts that the trial court should have at least precluded the experts from stating their conclusions with “absolute certainty excluding all other possible firearms.” The government does not *1139directly concede the point, but instead represents that the current policy of the United States Attorney’s Office “is to have firearms experts qualify their conclusions ‘to a reasonable degree of scientific certainty[.]’ ” In light of the government’s representation and the growing consensus that firearms examiners should testify only to a reasonable degree of certainty, see note 8, supra, we will assume, without deciding, that such experts should not be permitted to testify that they are 100% certain of a match, to the exclusion of all other firearms. Nevertheless, we agree with the government that any such error was harmless in this case. See Kotteakos v. United States, 328 U.S. 750, 765, 66 S.Ct. 1239, 90 L.Ed. 1557 (1946).11
Defense counsel thoroughly cross-examined the experts about three topics: their level of certainty; the subjective nature of their conclusions; and the lack of demonstrative evidence from which the jurors could assess their conclusions. Counsel pointed out, for example, that Morin was willing to “conclude that a cartridge casing is matched to a particular gun to the exclusion of all other possible guns,” even though he had not examined all those other firearms. Defense counsel emphasized that Mulderig had rendered an “opinion of 100% certainty that [two casings were] fired from the same weaponf,]” although he acknowledged there were inconsistencies between them. Counsel also questioned Mulderig about how he could “tell with certainty” that various marks were “imparted to the case head by the gun” instead of during the manufacturing process.
Mulderig agreed that his conclusions were “all subjective [based] on what you see in the microscope” and concurred with defense counsel’s assertion that “none of you [examiners] are scientists[.]” In a similar manner, Morin conceded that “the concept of sufficient agreement is purely a subjective one[.]” Morin agreed with the defense’s observation that, in the firearms identification “field, there’s no universal agreement as to how many features of similarity constitutes sufficient agreement.]” Defense counsel also asked, “[W]hat is there about this science that the average juror could look at to determine whether or not your conclusions are accurate?” When Morin suggested “that the jurors go back to [his] microscope, [where he] would show them” the matching patterns, defense counsel pointed out that Morin “didn’t bring [his] microscope” to court.
In his closing argument, Jones’s counsel used the examiners’ expressions of certainty to his advantage. Counsel asserted that, in light of the “completely and totally subjective” nature of examiners’ conclusions and the fact that neither examiner provided the jury with a visual depiction of the “points of comparison where they found similarities^]” “all [the jury] got” from the experts was a “trust me, this is the answer.” The defense suggested that, as a result, when the experts said, “I’m sure[, there’s a match, h]undred percents t]ake it or leave it[,]” the jury should “leave it.”
In the face of this record, the jury’s assessment of this evidence surely did not *1140turn on the difference between a “100% certain” conclusion and a “reasonably certain” opinion. Defense counsel did not present an expert to explain the difference or to opine that the government examiners’ confidence in their results was unjustifiably exaggerated. Nor did the defense put on an expert to point out any weaknesses in the methodology employed by the government experts. In fact, even though the trial court made it possible for the defense to conduct an independent test, it chose not to have an expert testify at all. See Roberts v. United States, 916 A.2d 922, 931 (D.C.2007) (“[W]hile ‘[n]o amount of attention to detail, auditing, and proficiency testing can completely eliminate the risk of error[,] ... the best protection an innocent suspect has from a false match is an independent test[.]’ ”) (quoting National Research Council, The Evaluation of Forensic DNA Evidence (1996)).
In sum, reversal is not warranted when the record is considered as a whole. An eyewitness to the murder identified appellant, who gave a detailed confession to a cellmate. Even if the government’s experts had qualified their conclusions “to a reasonable degree of scientific certainty,” the strength of the government’s case would not have been appreciably diminished. In these circumstances, “we can say, ‘with fair assurance, after pondering all that happened without stripping the erroneous action from the whole, that the judgment was not substantially swayed by the error.’ ” Goines v. United States, 905 A.2d 795, 802 (D.C.2006) (quoting Kotteakos, 328 U.S. at 765, 66 S.Ct. 1239).
D. Excluding a Photograph
When discussing the pattern matching process on cross-examination, Morin explained that experts “are looking for quality and quantity of detail that matches,” [that is,] “striated detail, which are lines, or [ ] impressed type detail, pot mark type detail, [or] circular detail.” Morin then described his laboratory’s policy “not to take photographs of our examinations^]” due to the fact “that photographs are two-dimensional representations of what we are looking at, which is generally three-dimensional.” Under a microscope, experts can determine the depth and width of impressed details, which is “not easily reproduced in a photograph.” According to Morin, “based on [ ] training and experience,” experts are also able to “filter out some of the extraneous detail that is necessarily left by [ ] residue in the barrel[.]” For those reasons, “[a] photograph may lead somebody who is not trained in the examination of firearms to the wrong conclusion.”
By contrast, Mulderig had taken a photograph through his comparison microscope and defense counsel used it to question him about his exam techniques and conclusions. First, the defense got him to agree that, although “there’s a pattern of striation marks[ ] on the primer, which you have determined to be consistent on both casings, ... [t]here are also marks on both the primer and the case head which do not appear to be consistent, right?” After Mulderig described the picture,12 defense counsel questioned him about several specific differences between the two images depicted there. For example, counsel asked: “Now on the silver one it would appear that there’s a firing pin impression on the very center of the primer? And there’s a similar crater-looking firing pin impression on the gold sample — evi*1141dence sample, but it’s to the right of the center of the primer, ... at about 3 o’clock?” Defense counsel questioned Mulderig about another mark at “9 o’clock, or maybe at 9:80,” on the gold sample which did not appear “at the same position on the silver shell casing[.]” The defense also inquired whether Mulderig agreed that “at 12 o’clock, on the base head of the gold cartridge case there’s a remarkable blemish ... [and] there is no similar remarkable image at the same 12 o’clock position on the silver case head?”
Although Mulderig readily conceded these apparent differences in the markings on the two casings as depicted in the photo, he also explained that “a trained examiner doesn’t come to any conclusions by looking at pictures. You have to look at the evidence.” He emphasized that, just because “[i]n the photo there is not” a similar mark on the two casings, that “doesn’t mean it wasn’t there under the microscope.... I’m looking at a microscope with very, very expensive equipment, called lenses, and a camera may not capture everything[.]” So when conducting an examination, he testified, “I don’t rely on the photographs; I’m relying on my eyes, and my microscope[.]”
Subsequently, at a bench conference held so as not to put defense counsel “on the spot in front of the jury,” the trial court “eonfirm[ed that counsel was] not at a point to move th[e] exhibit into evidence.” Defense counsel agreed, but said, “I do intend to move it into evidence.” The prosecutor then noted that he planned to object, given the experts’ testimony that a picture does not fairly and accurately capture everything an examiner sees under a microscope. The prosecutor mentioned this in advance, he explained, because Mulderig would not be available after the prosecution rested, and “so that [the defense] wouldn’t be trying to [admit it] in the absence of a witness in the defense case.” Defense counsel responded: “That’s fair. And I appreciate it. I’ll try and lay the foundation for it right now.”
Counsel then asked Mulderig: “[G]iven th[e] caveat” that “you testified [about] previously that it may not depict certain marks that you can see with your eyes in the microscope [because] the camera hasn’t picked [them] up,” is the photograph a “fair and accurate depiction of what you looked at through the microscope?” Mulderig answered: “For the most part, yes.” At no point during Mul-derig’s testimony did defense counsel seek to admit the photograph into evidence.
Later, Judge Dixon expressed the “tentative view [ ] that based on the witness’s testimony” to that point, he would not admit the photograph because it “would be more confusing than it is probative.” Instead, the defense would “need some sort of expert testimony that the photograph” was actually “demonstrable of either the lack of a comparison, or of the comparison.” The court gave such notice “just so that if you need to make arrangements with your expert you can do so.” Counsel responded: “We do intend to do that, Your Honor.” Yet, despite having retained a firearms expert who had looked at the photograph, conducted an independent test-fire, and examined the evidence, the defense did not present testimony from him or any other expert.
When the defense sought to introduce the picture into evidence at the end of its case, Judge Dixon excluded it, “having viewed the photograph with respect to what the defense contends may be differences that the [ ] expert should have taken into consideration, and based on the expert’s testimony ... that no expert would use that type of photograph to make an *1142analysis[,] and in the absence of any contrary evidence.... ”
1. Standard of Review
“The admission of photographs is “within the sound discretion of the trial judge.’ ” Henderson v. United States, 527 A.2d 1262, 1264 (D.C.1987) (quoting Rich v. District of Columbia, 410 A.2d 528, 531 (D.C.1979)). This is because “the trial judge [ ] is in the best position to determine [the photograph’s] relevance and accuracy.” Simms v. Dixon, 291 A.2d 184, 186 (D.C.1972); see also March v. United States, 362 A.2d 691, 704 (D.C.1976) (“the trial judge ... is in the best position to determine whether [the photographs] properly reflect the testimony or the circumstances sought to be depicted”) (brackets in original; internal quotation marks and citation omitted).
2. Analysis
The test of admissibility “is whether the photograph! ] accurately repre-sentes] the facts allegedly portrayed by [it].” Henderson, 527 A.2d at 1264 (quoting Simms, 291 A.2d at 186). Jones’s attorney reasoned that Mulderig “explained why the[ differences] don’t change his opinion about the identification, but it is relevant evidence, and the jury should be allowed to understand what he’s talking about.” However, both experts testified that such two-dimensional depictions of what examiners observe three-dimensionally under a microscope do not accurately represent the “physical differences” in the markings on the casings. According to both experts, photographs can be misleading. Because of its inherent deficiencies, Mulderig never unequivocally stated that the photograph was a “fair and accurate depiction” of what an examiner would see through a microscope.
“Discretion signifies choice.” (James) Johnson, v. United States, 398 A.2d 354, 361 (D.C.1979). We do “not render [our] own decision of what judgment is most wise under the circumstances presented,” but instead recognize that “the decision-maker exercising discretion has the ability to choose from a range of permissible conclusions.” Id. at 361-62. Although another judge might have admitted the photograph, perhaps with a cautionary instruction, Judge Dixon did not act outside the range of permissible conclusions by excluding it.
Moreover, we are not convinced that seeing the photograph would have affected the jury’s verdict. See id. at 367 (a trial court has not abused its discretion unless “the exercise of discretion was in error and ... the impact of that error requires reversal”) (emphasis added). Testimony that the photograph depicted several readily observable differences in the casings was certainly before the jury. Moreover, defense counsel extensively and effectively cross-examined Mulderig about those dissimilar markings and made the jurors well aware that Mulderig had not provided them with a visual means to evaluate his conclusion. Regardless of whether Judge Dixon erred in excluding the picture, doing so did not cause Jones any “significant prejudice,” Stone v. Alexander, 6 A.3d 847, 851 (D.C.2010) (internal citation and quotation marks omitted), and reversal is not warranted.
III. “Other Crimes” Evidence
A. Applicable Legal Principles
“It is a principle of long standing in our law that evidence of one crime is inadmissible to prove disposition to commit crime, from which the jury may infer that the defendant committed the crime charged.” Drew v. United States, 118 U.S.App.D.C. 11, 15, 331 F.2d 85, 89 (1964) *1143(emphasis in original). “Since the likelihood that juries will make such an improper inference is high, courts presume prejudice and exclude evidence of other crimes unless that evidence can be admitted for some substantial, legitimate purpose.” Id. at 15-16, 331 F.2d at 89-90 (footnotes omitted; emphasis added). Importantly, “the presumption of prejudice that attends other crimes evidence” does not apply if (1) the evidence is “offered for a substantial, legitimate purpose”; (2) the government demonstrates by clear and convincing evidence that the defendant committed the other crime; and (3) the legitimate probative value of the evidence is not substantially outweighed by the danger of unfair prejudice. Johnson v. United States, 683 A.2d 1087, 1092-93 (D.C.1996) (en banc).
Valid, non-propensity purposes “includ[e], but [are] not limited to[,]” proof of identity, motive, intent, absence of mistake or accident, and common scheme or plan. Johnson, 683 A.2d at 1092. Moreover, the “Drew strictures” do not apply where evidence “(1) is direct and substantial proof of the charged crime, (2) is closely intertwined with the evidence of the charged crime, or (3) is necessary to place the charged crime in an understandable context.” Id. at 1098. We review the trial court’s decision to admit evidence, including evidence of other crimes, for an abuse of discretion. Nellson v. United States, 989 A.2d 1122, 1126 (D.C.2010) (citing Artis v. United States, 505 A.2d 52, 56 (D.C.1986)).
B. Procedural Background
As explained above, firearms examiners determined that the .45-caliber pistol used in the Check Into Cash robbery in North Carolina (and later recovered from Ward’s North Carolina apartment) had been used to murder Valentine in the District of Columbia. Testing also established that the 9-millimeter pistol recovered from Ward’s apartment was the same 9-millimeter pistol used in the North Carolina robbery. Police also discovered, and store manager Geil identified, clothing that the robbers discarded behind the store. From that clothing, forensic analysts recovered DNA profiles matching Jones and Leaks.
Before trial, appellant and Leaks filed a motion to exclude evidence related to the North Carolina robbery. The government opposed the motion and, at a pretrial status hearing before Judge Satterfield, sought permission to show a two-minute surveillance video of the robbery and to introduce “the guns, the clothing, shell casings, bullets, as well as testimony from the [shooting] victim[.]” It argued that the North Carolina evidence was Drew identity evidence and would also “corroborate a key Government witness” (Hines) who heard “confessions by Ricardo Jones” to both crimes. According to the prosecutor, the forensic evidence from the Check Into Cash scene was also “direct proof’ (Johnson evidence) that appellant shot Valentine.
Judge Satterfield agreed that the North Carolina evidence was admissible under Johnson and Drew. Consequently, he explained, “all I’m looking at right now is trying to sanitize the prejudicial impact, because I think it clearly has probative value.” The court first sought to minimize the prejudice by precluding the guard from testifying, so “the jurors [would not] see the [victim] and what that person went through by getting shot[.]” At the court’s urging, the government proposed other ways of sanitizing the evidence, and the parties had lengthy discussions about possible stipulations that would affect the court’s balancing of probative value and prejudicial impact. Because the defense concentrated on persuading the court to *1144change its mind and entirely exclude evidence of the robbery, most of these discussions were fruitless.
Recognizing that the ballistics evidence would otherwise have little meaning, Judge Satterfield was inclined to let the government “establish that a gun was fired ... during the course of this robbery ... without establishing though that somebody was shot.” Nevertheless, the court’s tentative tone and its numerous requests for the defense to agree to one of the government’s proposed means of sanitization demonstrated that it had made no final decision on whether the government could establish that the guard was shot.13
On April 3, 2007, Leaks pleaded guilty and on December 31, 2007, the case was transferred to Judge Dixon, who read the transcripts related to Judge Satterfield’s ruling and discussed the “other crimes” issue with counsel at length. During one such discussion, defense counsel said he planned to “vigorously dispute” identification, including the DNA evidence.14 “They can prove that the gun was used at both places, but they really are not going to be able to prove that it was Mr. Jones who was in both places ... using that gun.” In a subsequent colloquy, the defense added that it would attack Hines’s credibility.15
The government explained that the prejudicial impact of the evidence from North Carolina had already been significantly limited by the decision that the guard could not testify. It was important to admit details like the robbers shooting the guard and taking his .38-caliber pistol to corroborate both Jones’s confession and Hines’s testimony. The prosecutor emphasized that Hines’s testimony was “already going to be significantly sanitized” because Jones had been charged in another assault with intent to kill case and had told Hines details about that crime as well, and the prosecutor had already instructed Hines not to discuss that matter. Therefore, “if we have got this witness who is not the most sophisticated person in the world, tip-toeing these off-limits issues[,] it is not fair to his presentation and demean- or.”
Judge Dixon recognized the importance of the jailhouse statement in which appellant said that he shot someone in both locations, had used the .45-caliber pistol on both occasions, and had stolen the guard’s .38-caliber pistol. The court also knew that the defense planned to blame the *1145North Carolina robbery and shooting on Mr. Leaks. Balancing the probative value of the evidence against its prejudicial effect, Judge Dixon ruled that the government could say there “was a nonfatal shooting” in North Carolina. He could not “see trying to sanitize both the North Carolina incident and the jailhouse statement without doing terrific prejudice to the evidence. I find that the probative value far outweighs the prejudice, because the whole purpose of the evidence is to prove [] identity[.]” Thereafter, Judge Dixon permitted store manager Geil to explain that the guard was shot and to narrate the surveillance video as it played.
C. Analysis
To begin, we recognize that even when other crimes evidence is admitted for a valid purpose, it may be used in an improper manner. Nevertheless, we have found no instances in this record where the prosecutor either “explicitly or implicitly suggested ... that the other crimes evidence evinced a predisposition to commit the charged crime.” Johnson, 683 A.2d at 1093. To the contrary. Referring to the robbery in closing, the government asked rhetorically: “Why did you hear about [this?] Because it’s powerful evidence of identification.”
Indeed it was. Evidence of the robbery undoubtedly was relevant to prove that Jones murdered Valentine. Although the murder weapon was not found in the District of Columbia, the police did recover a .45-caliber shell casing and a copper-jacketed bullet from the murder scene. That same pistol was used at the Cheek Into Cash robbery, and DNA evidence tied appellant Jones to that event. Moreover, Jones had stayed at the North Carolina home from which that pistol was recovered. See id. (approving admission under Drew identity exception of evidence that double homicide was committed with same gun used in murder at issue).
Identity was a hotly contested issue. Without the North Carolina evidence, the defense would have had freer rein to argue that Davis’s identification of Jones was unreliable and uncorroborated. According to Davis, his neighbor Leaks did not shoot Valentine — the shorter man with the medium build beside him did. Geil’s testimony about the robbery, the surveillance video, and the DNA evidence all were relevant to prove the identity of the shooter in the Valentine murder because they helped answer the question: Who was the shorter, heavier man with Leaks on Meigs Place?
Geil testified that the robbers carried a black bag (which appeared similar to the bag containing ammunition Ward found in her home), and that the taller of the two men wore a “stretchy, knit hat[]” and “dark blue work shirt[,]” while the “short, stockier one [wore] a lighter blue” work shirt. The black and white video also showed the bag, the clothing worn by the two robbers, and their relative sizes.16 DNA evidence established that Jones and Leaks were the robbers and that the robber in the dark knit hat and dark blue shirt was Leaks.17 Collectively, this evi*1146dence tended to prove that Jones was the shorter, stockier robber. And when considered along with the evidence that Jones and Leaks fled Meigs Place together and stayed together in North Carolina, it also made it more likely that Jones was the shorter, stockier shooter with Leaks on Meigs Place.
The North Carolina evidence had probative value not only as independent evidence of identity, but also because it corroborated other identity evidence. See Minick v. United States, 506 A.2d 1115, 1119 (D.C.1986) (parole papers and testimony concerning the papers admissible as evidence of appellant’s identity; although parole papers implied the existence of a prior criminal record, “[t]he witnesses’ specific reference to a detail like the parole papers added ‘narrative veracity’ to their testimony and reinforced their credibility to recall the events of the evening in question.”); cf. Strozier v. United States, 991 A.2d 778, 784 (D.C.2010) (“Concerning probative value, the pictures may be admitted ‘so long as they were in some way relevant, either independently or as corroborative of other evidence.’ ”) (quoting Pittman v. United States, 375 A.2d 16, 19 (D.C.1977)). In particular, this evidence powerfully corroborated Jones’s confession to Hines. Many courts have recognized that, while corroboration is not a classic example of a non-propensity purpose,18 “evidence of other crimes or acts is admissible to corroborate evidence that itself has a legitimate non-propensity purpose.” United States v. Bowie, 344 U.S.App.D.C. 34, 44, 232 F.3d 923, 933 (2000) (collecting cases); see also United States v. Bailey, 355 U.S.App.D.C. 64, 70, 319 F.3d 514, 520 (2003) (“[Other crimes] evidence might corroborate a witness’s testimony by showing plan, purpose, intent, etc. and therefore be admissible[.]”).
In his confession to Hines, appellant described his role in both shootings. See Bowie, 344 U.S.App.D.C. at 44, 232 F.3d at 933 (“[Prior crimes evidence often has] ‘multiple utility.’ ... It not only tended to establish Bowie’s intent and knowledge, but also corroborated Bowie’s confession to the Secret Service.”). The fact that the North Carolina evidence corroborated the details of Jones’s confession to his participation in the robbery suggests that Jones spoke with candor about his role in the murder as well.19 For example, Jones told Hines that .45-caliber and 9-millimeter pistols were used in the robbery (they were); that a security guard was shot (he was); and that they stole the guard’s .38-caliber pistol (they did).
The forensic evidence from the North Carolina robbery also was admissible as direct evidence of the Valentine murder because it helped to demonstrate that appellant possessed the murder weapon. See, e.g., Busey v. United States, 747 A.2d 1153, 1165 (D.C.2000) (“[T]estimony that *1147[appellant] possessed a revolver that might have been the murder weapon was not admitted improperly to establish criminal propensity. That evidence was directly relevant, and was not Drew evidence, because it constituted evidence supporting the charge that [appellant] was the person who [committed the charged crimes].”). In this case, the trail of forensic evidence traveled from the Valentine murder scene, to the check cashing store, to Ward’s residence. By leaving DNA and ballistics evidence at the robbery scene, and subsequently stashing the .45-caliber pistol at Ward’s apartment, appellant made evidence of the robbery part of the “direct and substantial proof’ that he possessed the murder weapon.
The defense’s closing argument reinforces the importance of the direct and corroborating evidence from North Carolina. Counsel began by talking about Davis’s identification of appellant and claimed, “[t]his is a one-witness case.” In addition to attacking Hines’s credibility, the defense asserted in turn that Davis “lied to you[,]” Ward “is not being completely honest with you[,]” and Geil was “mistaken.” Jones’s attorney ultimately suggested, “there’s not a witness in existence that puts that .45 in [ ] Jones’ hands in any time, at any place.... [Yet,] every time that gun is used, you know for a fact Joseph Leaks is there.”
The final step in a Drew or Johnson analysis is evaluating whether the probative value of the evidence is substantially outweighed by the danger of unfair prejudice. Johnson, 683 A.2d at 1099; Busey, 747 A.2d at 1165. “ ‘Unfair prejudice’ within its context means an undue tendency to suggest decision on an improper basis, commonly, though not necessarily, an emotional one.” Mercer v. United States, 724 A.2d 1176, 1184 (D.C.1999) (citing Old Chief v. United States, 519 U.S. 172, 180, 117 S.Ct. 644, 136 L.Ed.2d 574 (1997)).
We recognize (as did the trial court) that admitting evidence of an uncharged armed robbery will have a prejudicial impact (especially if the robbery includes a shooting). But there was no unfair prejudice in this case because the evidence was admitted for a valid purpose. Moreover, the trial court diligently “controlled] the development and use of the evidence at trial.” Johnson, 683 A.2d at 1101. Judge Satterfield precluded the government from putting the guard on the stand. (In addition, the prosecutor elicited from Geil that the security guard had survived.) Judge Dixon engaged in several colloquies with counsel throughout trial about how to limit the evidence appropriately.
Further limiting the danger of misuse, the trial court gave detailed instructions during the testimony about the North Carolina robbery and during its final charge. Judge Dixon made it clear that the “evidence is only being put forth to you for th[e] purpose of identity[,]” and that the jury was “not to consider this evidence [ ] as to whether or not the defendant is of bad character” or “has a criminal personality.” During his final instructions, he cautioned, “if you find that the defendant participated in the North Carolina offenses, consider that evidence only for the limited purpose of deciding whether the Government has proved beyond a reasonable doubt the identity of the defendant as the person who committed the murder ... [and you] may not consider the evidence [ ] for any other purpose.... [Y]ou may not [use it] to conclude that the defendant has a bad character or [ ] a criminal personality.”
Judge Ruiz asserts that the government had enough evidence linking appellant to the .45 caliber handgun without admitting *1148the video, details of the robbery, or the fact that the guard was shot. However, the discovery of the gun in Ward’s apartment could be, and was, used to point the finger of blame at Leaks. Without corroboration, Hines’s testimony would have been even more vulnerable to the attacks upon his credibility launched by Jones’s counsel. And without proof of how the robbery took place (including that there were two gunmen of different sizes), the jury might have found more persuasive counsel’s argument that the DNA evidence on the clothes failed to link appellant to the robbery and the gun.
As we recognized in Johnson, “in applying the reasonable doubt standard, [juries] may demand a showing of a very high probability of guilt, especially when one is accused of first-degree murder.” 683 A.2d at 1095 (“the murder of two innocent boys” committed with same weapon used in charged murder was “worse than deplorable,” but it was unlikely that the jury would reach “conclusions about [appellant’s] proclivity for violence before it was satisfied that he was guilty of the charged crime”); see also Old Chief, 519 U.S. at 189, 117 S.Ct. 644 (a jury that hears “a story interrupted by gaps of abstraction may be puzzled at the missing chapters, and jurors asked to rest a momentous decision on the story’s truth can feel put upon at being asked to take responsibility knowing that more could be said than they have heard”). Here, for good reason, the jury was allowed to hear evidence linking appellant to the murder on trial.
In sum, this was relevant evidence admissible under both Drew and Johnson. The critical issue was determining whether its probative value was substantially outweighed by the danger of unfair prejudice. “ ‘[T]he evaluation and weighing of evidence for relevance and potential prejudice is quintessentially a discretionary function of the trial court, and we owe a great degree of deference to its decision.’ ” Mercer, 724 A.2d at 1185 (quoting Johnson, 683 A.2d at 1095). The trial court performed a careful and conscientious balancing here, and we find no abuse of discretion.
IV. Bias Cross-Examination
Jones complains that the trial court foreclosed presentation of a defense theory that the police investigation was biased by a past relationship between Detective A, who assisted in the Valentine murder investigation, and the older brother of former co-defendant Leaks. He also asserts that the court impermissibly limited bias cross-examination of Tom Saunders, a former detective from Reidsville, North Carolina. We are not persuaded by either claim.
A. Legal Principles
Although a “trial court’s refusal to allow any questioning tending to elicit evidence of bias” denies a defendant his Sixth Amendment right to confront witnesses against him, Elliott v. United States, 633 A.2d 27, 32 (D.C.1993), it is well-established that this right “is not unlimited.” Coles v. United States, 808 A.2d 485, 489 (D.C.2002). Importantly, “a proper foundation must be laid” prior to pursuing “a line of questioning suggesting that a witness is biased.” Ray v. United States, 620 A.2d 860, 862 (D.C.1993). An adequate foundational “proffer is necessary to establish the relevance of a proposed inquiry by facts from which the trial court may surmise that the line of questioning is [in fact] probative of bias.” Melendez v. United States, 10 A.3d 147, 152 (D.C.2010).
B. Detective A
Prior to trial, the government disclosed that more than two decades previously, *1149when she was a teenager, Detective A had had a relationship with Leaks’s older brother, who was now dead. Although the defense was allowed to use this information in its investigation, the trial court cautioned that counsel could not refer to the matter “in open court” without prior approval. Neither Detective A nor Leaks testified at trial, so their credibility was not at issue.
Only once during trial did the defense attempt to show that favoritism had affected the investigation. During the testimony of the lead detective, defense counsel in essence asked why he had not arrested Leaks sooner. At the bench, counsel explained that he was “trying to develop the favoritism of the police investigation towards Mr. Leaks and against Mr. Jones.” He contended that the police “had plenty to get a warrant for ADW gun back in July, but because Detective [A] is involved in this case, [the detectives] chose not to[.]”
Judge Dixon did not abuse his discretion by precluding questioning about A’s long-past relationship with Leaks’s older brother. In the first place, the defense did not demonstrate how the timing of Leaks’s arrest was relevant to Jones’s guilt or innocence. See McCraney v. United States, 983 A.2d 1041, 1054 (D.C.2009) (“A defendant ‘has no right to present irrelevant evidence.’ ”). Moreover, the lead detective testified that he had in fact applied for a warrant prior to Leaks’s actual arrest, and the resulting proffers established that any delay in arrest was attributable to the prosecutor, not the police. Finally, it is entirely speculative to suggest that the relationship revealed to defense counsel would have biased the police investigation against appellant Jones.20
The record belies any argument that the decision to charge Jones as the shooter and Leaks as an accessory is evidence of police bias. Before the lead detective or Detective A arrived on the murder scene, Davis had already told other detectives that the person he recognized from his neighborhood (Leaks) was not the actual shooter. When Davis identified Leaks during the subsequent photo identification procedure, Davis said Leaks was not “the person who actually did the shooting[,]” but the one who “pointed a firearm at [me] and Mr. Valentine initially[,] and then apologized for having done so, prior to the shooting.” In light of this record, the defense did not meet its “obligation to establish a prima facie basis for the alleged bias[,]” Melendez, 10 A.3d at 153, and the trial court did not abuse its discretion.
C. Mr. Saunders
Tom Saunders photographed and took custody of the firearms Amanda Ward had discovered in her spare bedroom. At trial, the prosecution elicited that Saunders’ police department asked him to resign after an administrative investigation into allegations of sexual harassment that he initially denied but later acknowledged. (This happened approximately two years after he collected the evidence.) On cross-examination, Saunders reiterated that he falsely denied the allegations when first confronted with them and stated that he had submitted job applications to two police departments.
Appellant claims that the trial court erred by precluding the defense “from bringing out the nature of the underlying conduct, even though it was criminal and *1150had not been prosecuted.” Notably, Judge Dixon stated that he would allow the defense to ask whether Saunders was charged with a criminal offense as a result of the sexual harassment (he was not), but counsel did not ask the question.
The details of a prior bad act ordinarily are irrelevant unless they “ ‘bear[ ] directly upon the veracity of the witness in respect to the issues involved [in] the trial.’ ” Grayton v. United States, 745 A.2d 274, 280 (D.C.2000) (quoting Sherer v. United States, 470 A.2d 732, 737-38 (D.C.1983)); see Murphy v. Bonanno, 663 A.2d 505, 508-09 (D.C.1995) (same). Here, the details of Saunders’ conduct did not bear directly on his veracity, and Jones’s attorney had much more powerful ammunition available to impeach his credibility — Saunders had admitted that he lied when accused of job-related misconduct. Moreover, Saunders hoped to be a police officer once again and perhaps believed, rightly or wrongly, that currying favor with the prosecution in this case would enhance his job prospects. Under these circumstances, there was no error, let alone reversible error, in limiting cross-examination.
V. Other Claims of Error
The trial court declined to strike for cause a prospective juror who was an attorney in the Homicide Section of the United States Attorney’s Office. “In this case, however, we need not decide whether the judge abused [his] discretion because [the] prospective juror[ ] whom appellant sought to strike for cause [did not] end[ ] up on the jury that actually heard the case” — defense counsel removed her “by peremptory challenge^]” Johnson v. United States, 804 A.2d 297, 304 (D.C.2002) (citing United States v. Martinez-Salazar, 528 U.S. 304, 317, 120 S.Ct. 774, 145 L.Ed.2d 792 (2000) (“[A] defendant’s exercise of peremptory challenges ... is not denied or impaired when [he] chooses to use a peremptory challenge to remove a juror who should have been excused for cause[.]”)); see also Ahmed v. United States, 856 A.2d 560, 563-64 (D.C.2004).
Jones also asserts that the trial court erred in denying his motion to suppress Davis’s identifications of him as the shooter. We agree with the trial court’s decision, “both for reasons that the identification is reliable and because there was nothing about the array that was suggestive in terms of the description and information given by the witness, Mr. Davis[.]” See Jones v. United States, 879 A.2d 970, 975 (D.C.2005) (quoting Smith v. United States, 777 A.2d 801, 805 (D.C.2001)).
While the photo array may have been less than ideal because two of the photos appeared darker than the others, it was in no way impermissibly suggestive. See Buergas v. United States, 686 A.2d 556, 558 (D.C.1996). In any event, Davis’s identification was clearly reliable and thus properly admitted into evidence. See Black v. United States, 755 A.2d 1005, 1008 (D.C.2000) (articulating five factors to consider). Davis paid close attention to, and had an unobstructed view of, appellant’s face while he neared appellant and Leaks and ultimately stood just an “arm’s reach away” from them. Beyond those objective indicia of reliability, Davis repeatedly stated he would “never forget” the shooter’s face and knew he “picked out the right person who shot my man[.]”
Finally, appellant claims that the trial court was obliged to grant his last-minute motion for a continuance so his attorney could locate Tamika Queen, a potential alibi -witness. Counsel had relied upon appellant’s family members to contact Queen, but she did not come to court that morning, the day that evidence closed. Counsel acknowledged that Gerald Kelly, *1151who was present at trial, “can testify to the — the essence of the alibi....” In fact, Kelly did so.
Given the “wide latitude” granted to trial courts in such matters, Moctar v. United States, 718 A.2d 1063, 1065 (D.C.1998), we discern no abuse of discretion. Although counsel had announced at the outset of trial that Queen was a potential defense witness, he had not served her with a subpoena, despite a week-long mid-trial break. See Price v. United States, 545 A.2d 1219, 1228 (D.C.1988) (no abuse of discretion in denying continuance where, among other factors, defense had not subpoenaed the witness); Moctar, 718 A.2d at 1066 (same). Moreover, Queen’s testimony would have been cumulative of Kelly’s, and several other people supposedly had attended the birthday party which served as an alibi. Thus, appellant has not shown that the continuance was “reasonably necessary for a just determination of the cause.” Bedney v. United States, 684 A.2d 759, 766 (D.C.1996) (internal quotation marks and citation omitted).
For the reasons discussed, the judgments of conviction are
Affirmed.
. The manufacturing process leaves distinct marks inside each firearm, and the firing of ammunition imparts some of those special marks onto expended bullets and shell casings. For example, the manufacturing process leaves "lands, which are raised areas in the [ ] barrel, and grooves which are recessed areas in the barrel. When a bullet is fired through the barrel, then you [ ] get the negative [of the lands and grooves] imprinted onto the bullet itself.... This [type of] fine striated detail ... is the detail [experts] look[] for.”
When examining a cartridge casing from one crime scene and a gun recovered elsewhere, an examiner first "test fires” the firearm and collects the expelled ammunition components. Then he or she uses a comparison microscope ("two microscopes [connected by an] optical bridge”) to conduct a "side by side" comparison of the slugs and cartridge casings from the crime scene and the "test fires to see if [they share the] same unique detail[.]” Trained examiners thus determine if they can "match [a firearm] back to [previously] fired ammunition components[.]”
. Frye v. United States, 54 App.D.C. 46, 293 F. 1013 (1923).
. Appellant also complains that the trial court denied the motion without having read it. Yet, Jones had not made Leaks's written motion physically available to Judge Dixon. Leaks had pleaded guilty in April of 2007, when the cases were assigned to Judge Satter-field. Leaks’s 2006 motion was in his case jacket (not Jones's), and counsel conceded that he "didn’t take the logistical step of seeking leave to join [Leaks’s motion in writing] or reproducing [it] and filing it in Mr. Jones’ name.” Moreover, counsel did not request that the court defer ruling until after it had read the motion or reconsider its merits after giving counsel additional time to provide a copy. In any event, we have read Leaks's motion, and nothing in it undermines the conclusions we explain below.
. See State v. Lucero, 207 Ariz. 301, 85 P.3d 1059, 1062 (App.2004) ("To earn the right to a Frye hearing on previously accepted scientific evidence, the party opposing its admissibil*1137ity must preliminarily demonstrate that the method is no longer accorded general scientific acceptance.”) (internal quotation marks and citation omitted).
. See, e.g., Williams v. United States, 881 A.2d 557, 566 (D.C.2005); Peyton v. United States, 709 A.2d 65, 66-67 n. 7 (D.C.1996); Frendak v. United States, 408 A.2d 364, 368 (D.C.1979); Frezzell v. United States, 380 A.2d 1382, 1383 (D.C.1977); see also Goodall v. United States, 86 U.S.App.D.C. 148, 153, 180 F.2d 397, 402 (1950) ("evidence of such or similar [ballistics] tests or experiments is [generally] admissible in criminal cases in the federal courts”) (citing cases); Laney v. United States, 54 App.D.C. 56, 60, 294 F. 412, 416 (1923) (upholding admissibility of "testimony given by the expert witnesses, tending to establish that the bullet, extracted from the head of the deceased, was shot from the pistol found in the defendant’s possession”).
. Adina Schwartz, A Systematic Challenge to the Reliability and Admissibility of Firearms and Toolmark Identification, 6 Colum. Sci. & Tech. Rev. 2 (2005).
. Appellant urges us to consider recent reports of the National Research Council, Committee on Identifying the Needs of the Forensic Sciences Community, Strengthening Forensic Science in the United States: A Path Forward (2009), and the National Research Council, Committee to Assess the Feasibility, Accuracy and Technical Capability of a National Ballistics Database, Ballistic Imaging (2008), both of which were issued after the trial in this case. Although such evidence is not properly before us, even after considering it, we are still unpersuaded that pattern matching is no longer generally accepted.
. See, e.g., Commonwealth v. Pytou Heang, 458 Mass. 827, 942 N.E.2d 927, 946 n. 31 (2011) (requiring examiner to testify "to a reasonable degree of ballistics certainty” but noting that Association of Firearm and Tool-mark Examiners standards state that examiners should be conservative and not even testify as to a match unless, based on training and experience, they already consider it a "practical impossibility” that any other weapon could have been involved) (citing Theory of *1138Identification as it Relates to Toolmarks, 30 AFTE J. 86, 86-88 (1998)); United States v. Willock, 696 F.Supp.2d 536, 546-47, 571 (D.Md.2010) (pattern matching "generally accepted within the field of toolmark examiners”; adopting magistrate judge’s recommendation that “in light of two recent [NRC] studies ... toolmark examiners must be restricted in the degree of certainty with which they express their opinions”); United States v. Taylor, 663 F.Supp.2d 1170, 1175-80 (D.N.M.2009) (pattern matching “generally accepted among firearms examiners in the field”; given Schwartz’s testimony and both NRC studies, examiners should state their conclusions "to within a reasonable degree of certainty in the firearms examination field”); United States v. Diaz, 2007 WL 485967, at *11, 14 (N.D.Cal. Feb. 12, 2007) (pattern matching "generally accepted by the firearms-examiner community”; in view of Schwartz’s testimony, experts may state their opinions to a "reasonable degree of certainty in the ballistics field”); United States v. Monteiro, 407 F.Supp.2d 351, 372 (D.Mass.2006) (”[T]he community of toolmark examiners seems virtually united in their acceptance of the current technique"; considering, among other things, Schwartz's affidavit, an "examiner who has documented and had a second qualified examiner verify her results may testify ... that a cartridge case matches a particular firearm to a reasonable degree of ballistic certainty.”).
. See Fleming v. State, 194 Md.App. 76, 1 A.3d 572, 590 (2010) ("notwithstanding the current debate on the issue, courts have consistently found the traditional method [the comparative microscopic pattern matching technique] to be generally accepted within the scientific community”); Commonwealth v. Meeks, 2006 WL 2819423, at *29, 38-45, 50 (Mass.Super.Ct.2006) (examiners' testimony shows pattern matching is "generally accepted”; their testimony "overcomes Schwartz’s challenge” because she has never "been trained as a firearms examiner or conducted a firearms examination,” "conducted a test concerning the changes in toolmarks over time,” "taken a proficiency test[,]" "watched the manufacture of a firearm, spoken with firearm manufacturers, or fired a gun”).
. See Pytou Heang, 942 N.E.2d at 943 (even in light of recent studies, no error in denying request for Daubert hearing because testimony based on comparison matching "has long been deemed admissible” and a Daubert hearing is "generally not required where we have previously admitted expert testimony of the same type,” "for the same purpose,” and where there is no issue as to "whether the expert is qualified,” or "the appropriate methodology has been followed”); United States v. Cerna, 2010 WL 3448528, at *4-6 (N.D.Cal. Sept.1, 2010) ("no need for a pretrial Daubert hearing” because the Diaz order found pattern matching "passed Daubert muster”— meaning, among other things, it is “generally accepted by the firearms community”' — and ”[d]evelopments subsequent to the Diaz ruling, [like the Path Forward Report] have not undermined” it; court’s "gatekeeping role is not intended to serve as a replacement for the adversary system”) (internal quotation marks and citations omitted); Commonwealth v. Whitacre, 878 A.2d 96, 101 (Pa.Su per.Ct.2005) (pattern matching "generally accepted by the scientific community consisting of firearms experts and by a number of significant governmental bodies”; since it "has been in use since the 1930's, it is neither new nor original, but rather is [] offered all the time”) (citing Commonwealth v. Dengler, 843 A.2d 1241, 1243-45 (Pa.Super.Ct.2004) ("a Frye analysis is not triggered every time science enters the courtroom; it only applies when an expert seeks to introduce novel scientific evidence”)).
. Although appellant’s claim regarding expressions of certainty was arguably preserved in Leaks’s written motion, see note 3, supra, Jones's attorney never brought the issue "to the judge’s attention, nor did [ ] counsel ever renew the motion on the basis of any specific prejudice occurring during the trial.” Thorne v. United States, 582 A.2d 964, 965 (D.C.1990) ("A party who neglects to seek a ruling on his motion fails to preserve the issue for appeal.”). Nevertheless, the government has not asked us to apply plain error review, so we will assume that the point has been preserved for appeal.
. Mulderig agreed that "there’s two samples [in the] photograph, ... one on the left [that] is gold, ... [and] one on the right [that] is silverf.] ... And the silver one is the test fired cartridge[.] ... And the gold one is the piece of evidence from the crime scene[.]”
. We therefore reject appellant’s argument that Judge Satterfield had established the “law of the case” with respect to this question. See Kritsidimas v. Sheskin, 411 A.2d 370, 372 (D.C.1980) (the law of the case doctrine "does not apply where the first ruling has little or no ‘finality’ to it”).
. More than one individual’s DNA was present on the item of clothing (a black nylon used as a mask), which had Jones's DNA on it. The "predominant profile” at all sixteen genome locations tested (the "larger concentration” of DNA overall) matched Jones's DNA profile. Leaks could not be ruled out as the minor contributor to the DNA mixture. For that reason, defense counsel argued: "The DNA evidence doesn’t put Mr. Jones on the scene either. It’s no different than me stealing [the prosecutor's] necktie,” "committing a robbery with [it on,]” "leaving it on the scene[,]” and then "asking the jury to be-liefve,] ’well, [the prosecutor] obviously did this robbery because his DNA was found on the clothing.' ” The defense used the exact same analogy in its closing and made a similar argument in its opening statement.
.Counsel claimed, "there is as much connection to the .45 between Mr. Leaks [] as there is to Mr. Jones.... You obviously can’t give high credit to the statements made by the jailhouse informant”; "the credibility of his statement is going to be suspect ... [because] it is just as likely that he got all this information from Mr. Leaks and [ ] is now attributing it] to Mr. Jones in the interest of getting out of jail.”
. The video showed two men walking into the store, firing, and collecting money. The guard’s back was visible in the corner of the video frame prior to the robbery and then he dropped completely out of view after the men entered the store shooting. There was no gory portrayal of the shooting or its effect on the guard.
. The predominant DNA profile obtained from a black nylon cloth used as a mask matched Jones’s DNA profile; Leaks could not “be excluded as a contributor in the weaker profile” on that cloth. Leaks matched a partial profile developed from a brown knit hat and could not be excluded as a contributor to a DNA mixture profile developed from the dark blue shirt.
. Drew did not include "corroboration” in its list of permissible uses for "other crimes” evidence, but it explicitly stated that its list of valid, non-propensity purposes was non-exhaustive. Drew, 118 U.S.App.D.C. at 16 n. 10, 331 F.2d at 90 n. 10; see Johnson, 683 A.2d at 1092.
. See, e.g., Bowie, 344 U.S.App.D.C. at 44, 232 F.3d at 933 (in prosecution for possession of counterfeit currency, approving introduction of uncharged act of possession one month before charged crime, where proof of uncharged act corroborated defendant's confession to both acts) (citing United States v. Wimberly, 60 F.3d 281, 284-85 (7th Cir.1995) (in sexual molestation prosecution, court admitted defendant's confession to molesting another stepdaughter thirteen years earlier to bolster credibility of his confession to charged crime (both confessions were made to the same therapist); although defendant claimed he had falsely confessed to molesting recent victim, he had no reason "to fabricate a story concerning a totally unrelated incident”)).
. Jones points out that there was a related ex parte proffer (maintained under seal) that "appellate counsel [still] does not know” about. We have examined that material, and it reveals no valid basis for cross-examination.