State v. Thornton & Dunbar

State of Maryland v. William Thornton and James Dunbar, No. 46, September Term, 2025. Opinion by Killough, J. CRIMINAL LAW – PLAIN ERROR REVIEW The Supreme Court of Maryland determined that the law governing the admission of unqualified toolmark and firearms identification testimony was not “clear or obvious” error at either the time of trial or the time of appeal. This finding is dispositive under plain-error review. Abruquah v. State, 483 Md. 637 (2023), is a case-specific Daubert determination, not a per se prohibition on unqualified firearms identification testimony. CRIMINAL LAW – SIXTH AMENDMENT – RIGHT TO A PUBLIC TRIAL The Supreme Court of Maryland determined that, while the courtroom closures were not de minimis under the framework set forth in Kelly v. State, 195 Md. App. 403 (2010), a framework this Court now adopts, the closures were ultimately justified under Waller v. Georgia, 467 U.S. 39 (1984). The trial court advanced an overriding interest in juror safety and the integrity of deliberations, supported by adequate findings on the record regarding three escalating incidents of spectator misconduct, including direct contact between a co- defendant’s father and a sitting juror. The court also considered reasonable alternatives, and its response was no broader than necessary. Circuit Court for Baltimore City Case No.: 119343014 Case No.: 119343016 Argued: April 7, 2026 IN THE SUPREME COURT OF MARYLAND No. 46 September Term, 2025 ______________________________________ STATE OF MARYLAND v. WILLIAM THORNTON & JAMES DUNBAR ______________________________________ Fader, C.J., Watts, Booth, Biran, Gould, Eaves, Killough, JJ. ______________________________________ Opinion by Killough, J. Fader, C.J., Booth, and Biran, JJ., concur and dissent. ______________________________________ Filed: June 26, 2026 Pursuant to the Maryland Uniform Electronic Legal Materials Act (§§ 10-1601 et seq. of the State Government Article) this document is authentic. 2026.06.26 '00'04- 16:19:59 Gregory Hilton, Clerk  I. This appeal arises out of the convictions of Respondents William Thornton and James Dunbar in the Circuit Court for Baltimore City for offenses arising from the November 2019 murder of Donnell Brockington. Six individuals surrounded the victim and shot him ten to twelve times. The suspects fled in a vehicle, crashed into a tree, and four of them, including Thornton and Dunbar, were apprehended. Police recovered five firearms from the vehicle and one from a co-defendant’s person. DNA evidence linked all four co-defendants to the recovered firearms, and the DNA of both Respondents was found on a Desert Eagle 9mm pistol recovered from the front passenger floor of the getaway vehicle. The State’s firearms examiner testified at trial that two cartridge casings, one bullet, and two bullet fragments “were fired with” the Desert Eagle. None of the four co- defendants filed a pretrial motion challenging the reliability of that methodology, none requested a hearing under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), or its Maryland counterpart, Rochkind v. Stevenson, 471 Md. 1 (2020), and none objected when the examiner delivered his unqualified opinion. During the pendency of Thornton’s and Dunbar’s appeal, approximately seven months after Respondents’ trial, this Court decided Abruquah v. State, 483 Md. 637 (2023). Based on the record before us in that case, we held that the methodology of the Association of Firearm and Toolmark Examiners (“AFTE”) could support an opinion that ammunition evidence was “consistent with” having been fired from a particular firearm but could not support an unqualified opinion that the ammunitions fired from that specific firearm. Id. at 694–95. The Appellate Court of Maryland subsequently reversed Respondents’ convictions on plain-error review, concluding that the firearms examiner’s testimony “was exactly the kind of testimony that Abruquah prohibits.” Dunbar v. State, 2025 WL 2027549, *16 (Md. App. Ct. July 21, 2025). The State appealed the Appellate Court’s determination to this Court. Respondent Thornton separately challenges the trial court’s decision to close the courtroom during jury deliberations and to permit only family members from each side to attend the return of the verdict, a decision made in response to escalating incidents of spectator misconduct that culminated in a co-defendant’s father approaching a juror. The Appellate Court rejected Thornton’s public trial claim, finding the closures de minimis. We granted certiorari to consider two questions, which we rephrased as follows: 1. Did the Appellate Court of Maryland err in reversing Respondents’ convictions under plain-error review based on this Court’s decision in Abruquah v. State, when no defendant challenged the reliability of the firearms identification methodology at trial, no Daubert-Rochkind hearing was held, and the law concerning the admissibility of unqualified firearms identification testimony was unsettled at both the time of trial and the time of appeal? 2. Did the trial court violate Respondent Thornton’s Sixth Amendment right to a public trial when it closed the courtroom during jury deliberations and partially closed it during the return of the verdict, in response to three escalating incidents of spectator misconduct? We answer the first question in the affirmative and reverse the intermediate appellate court. The admission of the firearms examiner’s unqualified opinion was not “clear or obvious” error at either the time of trial or the time of appeal, which is dispositive under plain-error review. Abruquah is a case-specific Daubert determination, not a per se prohibition on unqualified firearms identification testimony. 2  With respect to Thornton’s argument that his right to a public trial was violated when the trial court partially closed the courtroom, we disagree and affirm the intermediate appellate court. Although we agree that the closures were not de minimis under the framework set forth in Kelly v. State, 195 Md. App. 403 (2010), which we adopt today, we conclude that the closures were justified under Waller v. Georgia, 467 U.S. 39 (1984). The trial court advanced an overriding interest in juror safety and the integrity of deliberations, supported by adequate findings on the record regarding three escalating incidents of spectator misconduct, including direct contact between a co-defendant’s father and a sitting juror. The court also considered reasonable alternatives, and its response was no broader than necessary. II. FACTS A. The Crime and Apprehension On the evening of November 13, 2019, six individuals surrounded Donnell Brockington in Baltimore City and an undetermined number of them shot him ten to twelve times. Surveillance video captured six men approaching the victim, one of whom was carrying a long gun. All six attempted to flee in a vehicle. A police officer, who had been alerted about the shooting, observed suspicious activity in a vehicle occupied by about six people and decided to follow it. He also requested assistance from the police department’s aviation unit. Together, they pursued the vehicle until it crashed into a tree at an intersection. Four of the vehicle’s occupants, Respondent William Thornton, Respondent James Dunbar, Shamar Jerry, and Anthony Clark, were apprehended in or near the vehicle. 3  Police recovered five firearms in connection with the apprehension: one handgun on Clark’s person and four firearms within the vehicle. The firearms recovered from the vehicle included a Desert Eagle 9mm pistol found on the front passenger floor. DNA evidence linked all four co-defendants to the recovered firearms. Dunbar’s DNA was found on three of the recovered guns, including a revolver containing five spent casings and a rifle. DNA from Thornton, Dunbar, and Clark was found on the Desert Eagle. The State’s firearms examiner testified at trial that two cartridge casings, one bullet, and two bullet fragments recovered from the murder scene and from the victim’s body during autopsy “were fired with” the Desert Eagle pistol. B. The Trial and the Absence of a Daubert Challenge Thornton, Dunbar, Jerry, and Clark were tried jointly before a jury in the Circuit Court for Baltimore City over a period of approximately three weeks in November and December 2022. The trial occurred against a particular legal backdrop that bears on the issues now before us. Approximately two years before trial, this Court had decided Rochkind v. Stevenson, 471 Md. 1 (2020), in which this Court abandoned the Frye-Reed general acceptance test for the admissibility of expert testimony in favor of the framework set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). In adopting Daubert, we expressly cautioned that the change “may mean, in a very real sense, that ‘everything old is new again’ with respect to some scientific and technical evidentiary matters long considered settled.” Rochkind, 471 Md. at 38 (citation omitted). Approximately six months before Respondents’ trial, in June 2022, this Court granted certiorari for a second time in Abruquah v. State, 479 Md. 63 (2022), to consider 4 the admissibility of unqualified firearms identification testimony under the new Daubert- Rochkind standard. We had previously vacated and remanded in Abruquah v. State, 471 Md. 249 (2020), with instructions for the trial court to reconsider the admissibility of the firearms identification evidence in light of Rochkind. The pendency of Abruquah before this Court was reported in The Daily Record, both at the time certiorari was granted and again when this Court heard oral argument in October 2022, weeks before Respondents’ trial began. 1 The grant of certiorari was also officially reported and published on the 0F Supreme Court of Maryland website. 2 Abruquah v. State, 479 Md. 63 (2022) (granting 1F certiorari on admissibility of toolmark and firearms identification evidence). Despite this background, none of the four co-defendants filed a pretrial motion under Maryland Rule 4-252 challenging the reliability of the AFTE methodology. None requested a Daubert-Rochkind hearing. None objected when the State’s firearms examiner delivered his unqualified opinion that the ammunition evidence “was fired with” the Desert Eagle. (Petitioner’s Br. at 5, 7–8). Four attorneys represented four defendants throughout 1 Steve Lash, Md. High Court to Weigh Ballistics Testimony Under Stricter Standard for Scientific Testimony, THE DAILY RECORD (June 7, 2022), https://thedailyrecord.com/2022/06/07/md-high-court-to-weigh-ballistics-testimony- under-stricter-standard-for-scientific-testimony/ [https://perma.cc/9DHF-96F6]; Steve Lash, Md. High Court Weighs Ballistics Testimony Under New Admissibility Standard, THE DAILY RECORD (October 4, 2022), https://thedailyrecord.com/2022/10/04/md-high- court-weighs-ballistics-testimony-under-new-admissibility-standard/ [https://perma.cc/RY8U-J3P5]. 2 Petitions for Writ of Certiorari – June, 2022, SUPREME COURT OF MARYLAND, https://www.mdcourts.gov/scm/petitions/202206petitions [https://perma.cc/2UTW- RUGA] (last visited June 15, 2026). 5 the proceedings, and not one raised any challenge to the reliability of the firearms identification methodology. The jury convicted Thornton of first-degree murder, use of a handgun in the commission of a crime of violence, transporting a handgun in a vehicle, possession of an assault pistol, possession of a handgun with a disqualifying conviction, conspiracy to commit murder, and conspiracy to use a handgun in a crime of violence. He was sentenced to an aggregate term of life in prison plus eighteen years. The jury convicted Dunbar of possessing an assault pistol, possessing a handgun with a disqualifying conviction, and conspiracy to use a handgun in a crime of violence. The jury was unable to reach a verdict on Dunbar’s charges for second-degree murder and use of a handgun in the commission of a crime of violence. The State subsequently nol prossed those charges. Dunbar was sentenced to an aggregate term of twenty years’ imprisonment. C. The Courtroom Closures Three incidents of escalating spectator misconduct led the trial court to close the courtroom during jury deliberations and to partially close it during the return of the verdict. The first incident occurred during the trial. The State informed the court that someone had used a cell phone to photograph bench conferences in which the court, the defendants, and counsel appeared. The photographs had been posted on Instagram with the hashtag “free dem boys.” The State represented that there were “direct connections between the individuals who own those Instagram accounts and at least one of the defendants.” The trial court firmly repeated its previous warning against cellphone use in 6 the courtroom, threatened to confiscate cell phones in the gallery if the conduct recurred, and stated that “I don’t expect to hear it again.” The second set of incidents occurred on the eleventh day of trial. The court was informed of “a disturbance between, amongst the families.” The court was further informed about an incident outside the courthouse involving “two individuals approached two other individuals who were in this courtroom watching the trial.” The third and most serious incident occurred after closing arguments on the twelfth day of trial. The court received a juror note indicating that co-defendant Clark’s father had approached Juror 11 in the hallway. At a bench conference, Juror 11 confirmed that he had been approached by an older man who “just said hi[]” and identified himself as Clark’s father. Juror 11 also told the court that he saw Clark’s father earlier in the day and recognized him then as a “childhood friend[.]” Other jurors were present when Clark’s father approached Juror 11. Juror 12 had written a note on behalf of the Juror 11 and other jurors who witnessed the interaction. At the same bench conference, Juror 12 stated that he heard Mr. Clark’s father say, “I’m tired of this shit or something like that” and saw Clark’s father shaking hands with Juror 11. Counsel for Dunbar described the incident as “harassing” the juror. The court individually voir dired each of the twelve jurors at the bench about the incident. Each juror confirmed that he or she could remain fair and impartial. The court then stated: I want to be abundantly clear. This is basically the third incident that is disturbing to this Court that has occurred during the course of this trial. . . . [F]or those reasons, I am not . . . comfortable with the public being in this 7  trial or observing it any more. I don’t want the jurors to feel that they can not deliberate freely. Every juror has said that they can be fair and impartial, but the Court does not want to impose any (unintelligible). For those reasons, the Court is not going to allow the public back until it’s time to hear the verdict. All four defendants objected to the closure. After hearing argument, the court denied the defendants’ motion for mistrial and adhered to its decision to close the courtroom. The court explained: [W]e have been in this case since November the tenth. Today is December first, so the public has had an opportunity to . . . observe the entire evidentiary portion of the trial. . . . Second, I warned everyone in the gallery that the Court had already had two other instances, and I thought it was abundantly clear that the Court was not going to tolerate any further disruption of this Court’s proceedings by way of phone or any other method. Third, an interaction with the juror, the Court sees as the highest form of disruption, and I am not going to take a chance on allowing it to occur any further. The court considered alternatives. It contemplated excluding only the individual who approached Juror 11 but rejected that option in light of the prior failures of warnings to prevent recurrence. It planned to take the verdict one defendant at a time, which would have allowed more family members in the courtroom for each individual verdict but rejected that option after consulting courtroom security personnel. The court adopted the compromise of full closure during deliberations and partial reopening for the verdict. Immediately after the court decided to fully close the courtroom until the verdict reading, the State acknowledged that it was “aware of who the individual was” that approached Juror 11 and mentioned that “[i]f this individual comes to the State’s attention again,” the State “may ask” the Sheriff’s office to assist “in investigating a contempt of Court charge.” During the closed deliberations, the jury sent six other notes in addition to the note stating that Clark’s father had interacted with Juror 11 during the lunch recess. Three were 8 scheduling requests asking when the jurors could leave for the day. One asked about the effect of an undecided verdict on unanimous verdicts. One prompted the court to give an Allen-type charge. One announced that the jury had reached verdicts on all charges except two counts against Dunbar. No defendant objected to any of the court’s proposed responses to the jury’s notes. The Allen-type charge was a rereading of Maryland Criminal Pattern Jury Instruction 2:01, the same instruction the jury had received in written form and heard read aloud earlier in open court. For the reading of the verdict, the trial court partially reopened the courtroom. The court permitted two family members for each of the four defendants and five family members for the victim’s family. The court explained that its capacity was “forty-five basically” persons in total, including corrections officers, counsel, and defendants. The court further explained that it remained “concern[ed] for the jury’s safety[.]” The court emphasized its concern that families be treated equally: The limitation on family attendance “precludes or foregoes anyone feeling that the Court is treating anybody’s family different than the other.” Ultimately, the jury convicted Thornton of first-degree murder, use of a handgun in the commission of a crime of violence, transporting a handgun in a vehicle, possession of an assault pistol, possession of a handgun with a disqualifying conviction, conspiracy to commit murder, and conspiracy to use a handgun in a crime of violence. He was sentenced to an aggregate term of life imprisonment plus eighteen years. D. Post-Trial and Appellate Proceedings On December 14, 2022, within the ten-day deadline prescribed by Maryland Rule 4-331(a), Thornton filed a written motion for a new trial. The motion alleged concerns 9 about his right to a public trial, the sufficiency of the evidence to support one of his convictions, and a complaint about the prosecutor’s closing argument. The motion did not address the firearms identification testimony. This Court issued its decision in Abruquah v. State, 483 Md. 637 (2023), on June 20, 2023. Nine months after the verdict, at the hearing on his motion for a new trial on October 12, 2023, Thornton’s counsel raised Abruquah orally for the first time. Counsel argued that the firearms examiner’s testimony tying ammunition evidence to the Desert Eagle as “an exact match” had been “placed in question by our highest Court.” The prosecutor responded on the merits, arguing that the examiner’s opinion was not an unqualified opinion, that Abruquah arguably did not extend to shell casings or cartridge cases, or hold that firearms evidence is now unreliable, and that the result would not have changed the verdict in any event. The trial court denied the motion. The court stated that “Counsel is correct regarding his statement of the case law regarding the ballistics evidence.” At the same time, the court found that Abruquah “had not yet been settled” at the time of trial, that the examiner’s testimony could not be considered not qualified, and that the jury could have relied on the DNA evidence linking Thornton to the firearm. Thornton was then sentenced. On appeal to the Appellate Court, Respondents and co-defendant Jerry collectively raised six claims of error. Both Respondents conceded that the Abruquah issue had not been preserved at trial. Both asked the Appellate Court to review the issue for plain error. On the public trial issue, Thornton separately claimed that the closures violated his Sixth Amendment rights. 10  The Appellate Court affirmed on five of the six claims, including Thornton’s public trial claim. With respect to the public trial issue, the Appellate Court applied the three- factor framework from Kelly v. State, 195 Md. App. 403 (2010), and concluded that both the deliberations closure and the partial verdict closure were de minimis. The Appellate Court reversed the convictions of Thornton and Dunbar on the firearms identification issue. The court held that the examiner’s testimony “was exactly the kind of testimony that Abruquah prohibits.” The court remanded for a new trial. We granted the State’s petition for a writ of certiorari to consider whether the Appellate Court erred in applying plain-error review. We also granted Thornton’s cross- petition to consider whether the closures violated his right to a public trial. III. STANDARD OF REVIEW Two distinct standards of review govern the two questions before us. The first concerns plain-error review of an unpreserved evidentiary claim. Both Respondents conceded below that their challenge to the firearms identification testimony was not preserved at trial. Both asked the Appellate Court to review the issue for plain error. Plain-error review is “reserved for errors that are compelling, extraordinary, exceptional or fundamental to assure the defendant a fair trial.” Yates v. State, 429 Md. 112, 130 (2012) (citation modified). Before an appellate court may exercise its discretion to reverse on this basis, four conditions must be satisfied: • First, there must be an error or defect that has not been intentionally relinquished or abandoned. 11  • Second, the legal error must be clear or obvious, rather than subject to reasonable dispute. • Third, the error must have affected the appellant’s substantial rights, which ordinarily means that the appellant must demonstrate that the error affected the outcome of the proceedings. • Fourth, the error must seriously affect the fairness, integrity, or public reputation of judicial proceedings. Beckwitt v. State, 477 Md. 398, 464 (2022) (citation omitted). All four conditions are mandatory prerequisites; if any of them are not met, plain-error review is unavailable. Id. The first two prerequisites, whether there was an error and whether the error was clear or obvious, present legal questions that we review without deference. See State v. Wallace, 372 Md. 137, 144 (2002). The third and fourth prerequisites, and the ultimate decision whether to grant relief, are committed to the discretion of the reviewing court. That discretion has limits. A court abuses its discretion when its decision rests on an error of law. Rochkind, 471 Md. at 11. Accordingly, if an appellate court grants plain-error relief based on a mistaken legal conclusion that an error was clear or obvious, the grant of relief cannot stand. The second standard of review concerns appellate review of a claimed Sixth Amendment violation regarding the court closure. Where, as here, a defendant’s constitutional claim was preserved through contemporaneous objection, we make our own independent constitutional appraisal of the record. Longus v. State, 416 Md. 433, 457 12 (2010). We accept the trial court’s findings of fact unless they are clearly erroneous, but we apply the law to those facts independently. Id. IV. DISCUSSION We address the firearms identification issue first because it is dispositive of Respondents’ appeal of their convictions. We then turn to Thornton’s public trial cross- petition. The Firearms Identification Testimony The Appellate Court reversed Respondents’ convictions under plain-error review on the ground that the firearms examiner’s testimony “was exactly the kind of testimony that Abruquah prohibits.” Dunbar v. State, 2025 WL 2027549, *16 (Md. App. Ct. July 21, 2025). Both Respondents had conceded that the issue was not preserved below and had asked for plain-error review. The Appellate Court concluded that the examiner’s opinion that the ammunition evidence “was fired with” the Desert Eagle was indistinguishable from the testimony we found inadmissible in Abruquah and that the trial court therefore abused its discretion in admitting it. Id. at *17. For the reasons detailed below, we disagree. Plain-error review requires that the error be “clear or obvious, rather than subject to reasonable dispute[.]” Beckwitt, 477 Md. at 464. The admission of the firearms examiner’s testimony was not clear or obvious error at either the time of trial or the time of appeal. That conclusion is dispositive. We explain that conclusion in Section A. We then address, in Section B, the reviewability of unpreserved Daubert challenges under plain-error review. In Section C, we reject 13 Dunbar’s alternative theory that the State, as the proponent of the firearms identification evidence, bore the burden of initiating its own Daubert hearing. Finally, in Section D, we reject Thornton’s separate argument that he is entitled to de novo review of an issue he never raised in writing. A. The Error, If Any, Was Not Clear or Obvious The second prerequisite to plain-error review requires that the error be “clear or obvious, rather than subject to reasonable dispute[.]” Beckwitt, 477 Md. at 464. “Clear or obvious” means more than that the error is one a careful court might find on close examination. It means that the error is not reasonably debatable. Id. (declining to exercise plain-error review where “any error . . . was not clear and obvious but rather is subject to reasonable disagreement”). The admission of the firearms examiner’s testimony in this case fails that standard, both with respect to the law as it stood at the time of trial and with respect to the law as it stood at the time of appeal. 1. The law was unsettled at the time of trial. Respondents’ trial took place in November and December 2022. By that point, the legal framework governing the admissibility of expert scientific testimony in Maryland had been the subject of significant change, and the admissibility of conclusive firearms identification testimony specifically was the subject of pending appellate review. In August 2020, approximately two years before this trial, this Court decided Rochkind v. Stevenson, 471 Md. 1 (2020). Rochkind replaced the longstanding Frye-Reed general acceptance test for expert scientific testimony with the more searching framework set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). Rochkind, 14 471 Md. at 36. We did not adopt Daubert quietly. We expressly cautioned the bench and bar that “[t]he shift to Daubert may mean, in a very real sense, that ‘everything old is new again’ with respect to some scientific and technical evidentiary matters long considered settled.” Id. at 38 (citations omitted). That cautionary language informed the bench and the bar that the admissibility of expert testimony previously settled under Frye-Reed, including testimony from the forensic disciplines, was now open to renewed scrutiny under the Daubert framework. Two additional developments confirmed that firearms identification evidence was specifically among the categories of evidence newly subject to challenge. In October 2020, this Court summarily granted certiorari in Abruquah v. State, 471 Md. 249, 250 (2020), vacated, and remanded with instructions for the trial court to reconsider the admissibility of firearms identification evidence in light of Rochkind. That decision placed firearms identification evidence on the bench’s and bar’s radar as an evidentiary matter newly in flux. In June 2022, approximately six months before Respondents’ trial began, this Court granted certiorari in Abruquah for the second time. Abruquah v. State, 479 Md. 63 (2020). The pendency of Abruquah before this Court was also published on our website 3 and 2F reported in The Daily Record, both at the time certiorari was granted and again when the Court heard oral argument in October 2022, weeks before this trial began. 4 3F 3 See Petition for Writ of Certiorari – June, 2022, supra at 7, n.2 4 See Lash, supra at 7, n.1 15  The Appellate Court reasoned that the law was nevertheless settled at the time of trial because firearms identification testimony had long been admitted under the Frye-Reed standard and “was generally accepted” in the relevant scientific community. Dunbar, 2025 WL 2027549 at *19; (E. 46). We disagree, for two independent reasons. First, even accepting the Appellate Court’s premise, its conclusion does not follow. If the law was settled at the time of trial that the testimony was admissible, then the trial court ruled in accordance with settled law, and a ruling consistent with settled law cannot constitute clear or obvious error. Second, the premise is wrong. Frye-Reed was no longer the law of Maryland. Rochkind, 471 Md. at 38. It had been replaced more than two years before this trial, and the law governing the admission of unqualified AFTE testimony under the new standard was not settled in either direction. An error that occurs in an area of law not yet authoritatively resolved is, by definition, subject to reasonable dispute and cannot be “clear or obvious[.]” Beckwitt, 477 Md. at 464. Moreover, there are differing opinions about whether the “clear or obvious” requirement is measured as of the time of trial or the time of appellate review. Compare Henderson v. United States, 568 U.S. 266, 273 (2013) (ruling that the error must be plain at the time of review), with id. at 285–94 (Scalia, J., dissenting) (concluding that the error must be plain at the time it was committed). We need not resolve that question today. The law governing unqualified firearms identification testimony was unsettled at the time of trial, supra at 17-19, and remained unsettled at the time of appeal, infra at 19-22. Under any formulation of the temporal inquiry, the Respondents cannot show clear or obvious error. 16  In sum, the unsettled state of the law placed the Respondents on notice that the issue was open. With Rochkind providing the governing standard, Abruquah pending before this Court, and the issue being publicly debated, Respondents’ counsel had every reason and opportunity to file a pretrial Daubert motion or, at the very least, to object at the time of the testimony. Four attorneys representing four defendants did neither. Plain-error review is not designed to rescue litigants from strategic choices made when the legal landscape is uncertain. 2. The law remained unsettled at the time of appeal; the holding in Abruquah is not a per se rule. The Appellate Court’s analysis treated Abruquah as having resolved the question of unqualified firearms identification testimony with categorical clarity. It did not. Abruquah was a case-specific Daubert determination based on a particular evidentiary record. Several features of our opinion make this plain on its face. We described the scope of our holding in unambiguous terms. We wrote: Based on the evidence presented at the hearings, we hold that the circuit court did not abuse its discretion in ruling that [the expert witness] could testify about firearms identification generally, his examination of the bullets and bullet fragments found at the crime scene, his comparison of that evidence to bullets known to have been fired from [the defendant’s] revolver, and whether the patterns and markings on the crime scene bullets are consistent or inconsistent with the patterns and markings on the known bullets. However, the circuit court should not have permitted the State’s expert witness to opine without qualification that the crime scene bullets were fired from [the defendant’s] firearm. Abruquah, 483 Md. at 698 (emphasis added). The Court’s holding was tied to “the evidence presented at the hearings.” Id.; see also id. at 696 (“[B]ased on the record 17 here, . . . firearms identification has not been shown to reach reliable results linking a particular unknown bullet to a particular known firearm.” (emphasis added)). We further acknowledged that other studies on the reliability of the AFTE methodology existed but were not before us. We declined to consider them, explaining: “We have not considered those studies in reaching our decision. If any of those studies materially alters the analysis applicable to the reliability of the [AFTE] theory of firearms identification, they will need to be presented in another case.” Id. at 656 n.6. We further stated that we did “not preclude the possibility that the [analytical] gap may be closed in the future,” id. at 694, and we acknowledged that different conclusions might be reached by experts “who are asked the right questions or have the benefit of additional studies and data[,]” id. at 696. This language is impossible to square with a per se rule. A per se rule, by its nature, applies regardless of the underlying record. Abruquah by its express terms applies only to a record like the one before us in that case. And where reasonable judges might disagree about whether a categorical rule exists at all, and if so, what it covers, admission of an opinion that falls within the disputed zone cannot be characterized as a clear or obvious error. Our subsequent disposition of the petition for certiorari in Harris v. State confirms this understanding. Pet. Docket No. 338, Sept. Term 2024 (filed Jan. 29, 2025) (unpublished) (Fader, C.J., statement on denial of cert.). In a statement accompanying the denial of certiorari, Chief Justice Fader cautioned that the denial “should not be considered a departure” from the suggestion in Abruquah that additional studies presented in a future 18 case might alter our analysis. Id. The Chief Justice further explained that it would be “more appropriate to consider certiorari based on a record that is created following our decision in Abruquah.” Id. That statement reflects the same principle: Abruquah contemplates case-by-case litigation on developed records, not automatic exclusion regardless of the record. Even setting aside the express terms of Abruquah, the broader landscape of authority confirms that the admissibility of unqualified firearms identification testimony remains the subject of reasonable disagreement. Federal circuits continue to admit this category of testimony under Daubert. See, e.g., United States v. Hunt, 63 F.4th 1229, 1233 (10th Cir. 2023) (affirming testimony that cartridge cases “were fired from” the same weapon); United States v. Brown, 973 F.3d 667, 702, 704 (7th Cir. 2020) (affirming testimony that casings “were fired by the same firearm”); United States v. Johnson, 875 F.3d 1265, 1280– 81 (9th Cir. 2017) (affirming testimony that bullets “matched . . . to a reasonable degree of ballistics certainty”). Some state courts in Daubert jurisdictions have reached similar conclusions. See, e.g., State v. Mills, 623 S.W.3d 717, 732 (Mo. Ct. App. 2021) (affirming admissibility of firearm and toolmark identification evidence); Willie v. State, 274 So. 3d 934, 939–40 (Miss. 2018) (same); Garrett v. Commonwealth, 534 S.W.3d 217, 222–23 (Ky. 2017) (same). The Respondents’ burden under the second prerequisite to plain-error review is to demonstrate that the admission of the firearms examiner’s testimony was not reasonably debatable. They have not carried that burden. The Appellate Court’s contrary conclusion was an error of law and an abuse of its discretion to grant plain-error review. 19  B. The Absence of a Daubert Record Below Beyond the dispositive failure on the second plain-error prerequisite, this case raises a distinct concern about the reviewability of unpr