OPINION
PAGE, Justice.In March 2010 Jerrell Michael Brown was convicted of aiding and abetting first-degree murder for the benefit of a gang in connection with the shooting death of Darius Ormond Miller, which occurred on August 29, 2008. On appeal, Brown challenges his conviction, claiming that the trial court violated his right to a public trial and erred in its evidentiary rulings and jury instructions. Brown also claims the prosecutor violated his right to a fair trial by failing to disclose impeachment evidence. Because the facts of this case do not implicate the right to a public trial, the trial court did not err in its evidentia-ry rulings or its jury instructions, and the undisclosed impeachment evidence was not material, we affirm Brown’s conviction.
On August 29, 2008, Darius Miller was fatally shot outside a club in downtown Minneapolis. Following a police investigation, the State filed a criminal complaint alleging that Jerrell Brown aided and abetted the second-degree intentional murder of Miller. Minn.Stat. § 609.19, subd. 1(1) (2010); Minn.Stat. § 609.11 (2010); MinmStat. § 609.05, subd. 1 (2010). The State later presented the evidence against Brown to a grand jury. To link Brown to Miller’s murder, the State provided the grand jury with forensic evidence that a ,9mm bullet casing found near Miller’s body matched a .9mm bullet casing recovered from the scene of a June 2008 reckless-discharge-of-a-firearm offense, which occurred in Richfield and to which Brown had previously pleaded guilty.1 Using a transcript of Brown’s guilty plea, the State established Brown’s participation in the June 2008 Richfield shooting incident. The State provided the grand jury with additional evidence, including eyewitness testimony and surveillance camera footage. The grand jury indicted Brown on four *613counts of murder: (1) aiding and abetting first-degree murder, Minn.Stat. §§ 609.05, subd. 1, 609.185(a)(1) (2010); (2) aiding and abetting first-degree murder committed for the benefit of a gang, Minn.Stat. §§ 609.05, subd. 1, 609.185(a)(1), Minn. Stat. § 609.229, subd. 2 (2010); (3) aiding and abetting second-degree intentional murder, MinmStat. §§ 609.05, subd. 1, 609.19, subd. 1(1); and (4) aiding and abetting second-degree intentional murder committed for the benefit of a gang, Minn. Stat. §§ 609.05, subd. 1, 609.19, subd. 1(1), 609.229, subd. 2.
Brown filed a pretrial motion to dismiss the indictment, claiming the evidence of the June 2008 Richfield shooting incident “tainted” the grand jury because the evidence involved a previous bad act that did not fall within any of the exceptions to Minn. R. Evid. 404(b) (“Evidence of another crime, wrong, or act is not admissible to prove the character of a person in order to show action in conformity therewith.”). Brown also filed a motion to exclude Spreigl evidence related to the Richfield shooting incident. In response to Brown’s motion to exclude evidence related to the Richfield shooting incident, the State argued that the evidence was properly introduced at the grand jury proceedings for two reasons. First, the Richfield shooting was “inextricably intertwined” with Miller’s murder. Second, the Richfield shooting evidence fell within an exception to Rule 404(b) because the evidence was offered to prove identity, opportunity, and lack of mistake or accident. The trial court denied Brown’s motion to dismiss the indictment, explaining that the Rich-field shooting evidence was
appropriately introduced for the stated limited purpose of connecting [Brown] to possession of one of the guns used at the scene of the homicide by way of forensic evidence that linked a shell easing found at the scene of the earlier crime to which the defendant pled guilty to unlawfully possessing a firearm to a shell casing found at the scene of the homicide being considered by the grand jury.
At a subsequent Rasmussen hearing, the trial court discussed the Richfield shooting evidence in the context of whether the evidence would be admissible at trial. The trial court ruled that the Rich-field shooting evidence would be admissible at trial because the evidence was “so intertwined with the evidence that the State wants to present and is authorized to present under the evidentiary rules.” (Emphasis added.)
At trial, the court allowed the State to introduce testimony that Brown and Miller were members of rival gangs. C.W. provided lay testimony about the gang to which Brown belonged: the Shotgun Crips. C.W. admitted that he was a former member of the Shotgun Crips and that, in exchange for his testimony in Brown’s case, he received a reduced sentence in an unrelated case.2 Sergeant Bart Hauge provided expert testimony that generally described Minneapolis gangs, including the Shotgun Crips; their participation in criminal activities; and some rituals and inner workings of gang memberships and hierarchies.
The State also introduced the following evidence. Less than 3 hours before Miller’s murder, around 12:30 a.m. on August 29, 2008, Brown and four acquaintances, M.G., D.S., J.H., and T.S., were at a bar in downtown Minneapolis. Following an altercation, bar security personnel escorted *614T.S. out of the bar. A bouncer from a nearby bar testified that two individuals subsequently identified as Brown and T.S. drove away in a colored Mercury Sable which was determined later to be registered to J.H.’s sister. The bouncer explained that he wrote down the license plate number of the vehicle because he believed it belonged to a customer. He also testified that he thought he saw a handgun.
At 3 a.m., witnesses saw M.G., D.S., and J.H. attack Miller in front of a club in downtown Minneapolis. A club security camera captured footage of the initial attack, but the fight soon moved off-camera. During the fight, someone yelled, “You better go get a gun.” Eyewitnesses later heard several gunshots, followed by a pause, and then two close-range gunshots. The witnesses reported seeing an individual, who wore a white undershirt and a large necklace and had his hair in a ponytail, come up the club stairs just before the two close-range gunshots were fired. One witness testified that this same individual shot Miller. After shooting Miller, the individual ran back down the stairs and drove away in a dark-colored Mercury Sable or Ford Taurus. Much of the eyewitness testimony was corroborated by security camera footage from the club. One witness later identified Brown as the individual wearing the white undershirt and large necklace.
In addition to the eyewitness testimony, the State introduced testimony from two former jail mates to whom Brown had confessed committing the crime. Consistent with its pretrial rulings, the trial court allowed the State to introduce evidence that a bullet casing recovered as part of the police investigation of the Richfield shooting incident matched a casing found at the scene of Miller’s murder. The State was also allowed to introduce evidence that, following Brown’s guilty plea in the Richfield shooting case, he remained in the Hennepin County jail until August 28, 2008. A jail security camera captured footage that showed Brown leaving the jail 12 hours before Miller’s murder, with his hair in a ponytail and wearing a large necklace, white tank top, and dark pants. The State used that jail videotape to bolster the testimony of the witness who identified Brown as the person seen on the security camera footage from the club. Finally, the State was permitted to read portions of the transcript of a videotape of Brown pleading guilty to the Richfield shooting incident to provide context for the bullet casings and the jail videotape.
Brown argued at trial that the theory of the murder provided by the State was internally inconsistent. Brown’s attorney cross-examined the State’s witnesses, many of them extensively, focusing on inconsistencies between testimony given at the scene, the grand jury, and trial. Brown did not testify or call any witnesses in his defense.
Following closing arguments but before giving jury instructions, the trial court ordered that the courtroom door be locked for the duration of jury instructions. In explaining the situation, the judge stated on the record:
For the benefit of those in the back. I am about to begin giving jury instructions. While that is going on the courtroom is going to be locked and people are not going to be allowed to go in and out.
So, if anybody has to leave, now would be the time. You are welcome to s[t]ay. But I just want to make sure that everybody knows that the courtroom is going to be locked. We are all good? Deputy?
Once the courtroom door was locked, no spectators were let in or out during the *615jury instructions, but no spectators who were in the courtroom at .the time jury instructions began were forced to leave. At the close of the instructions, the trial court handed out copies of the jury instructions and sent the jury to deliberate.
The jury found Brown guilty of all four counts of murder. After convicting Brown of aiding and abetting first-degree murder committed for the benefit of a gang, the trial court sentenced him to life imprisonment without possibility of release, plus an additional year of imprisonment based on the murder having been committed for the benefit of a gang.
Approximately 2 months after Brown’s conviction and sentencing, the State disclosed at a post-trial hearing that the prosecutor failed to disclose an additional plea bargain between C.W. and another county attorney’s office. Under the undisclosed plea bargain, C.W. agreed to “comply with all conditions of release in the Hennepin County matter, that he testify truthfully in the Hennepin County case at issue, if requested to do so by the state, and that he comply with all conditions of release in this matter as well.” The trial court ruled that because it could not order a new trial (the deadline for filing a new trial having passed before the hearing), it did not have jurisdiction to conduct a post-trial Brady violation hearing and any such motion would need to be filed as a postconviction proceeding.
Brown then filed his direct appeal. After reviewing the trial court transcripts, Brown filed a motion with our court pursuant to Sanchez-Diaz v. State, 758 N.W.2d 843 (Minn.2008) (encouraging defendants to stay the appeal for remand on issues that require a factual record), seeking to stay his direct appeal and obtain a remand to the trial court for a Brady hearing and to clarify the record on the admissibility of certain evidence admitted at trial. We granted Brown’s motion on December 23, 2010. Brown then filed a petition for post-conviction relief with the district court.
In his petition for postconviction relief, Brown argued that: (1) the existing record contained no ruling by the trial court on the admissibility of the Richfield shooting incident; and (2) Brown was entitled to a new trial because the State’s failure to disclose the additional plea bargain between C.W. and the other county attorney’s office constituted a Brady violation. The postconviction court denied relief without holding an evidentiary hearing, affirming the trial court’s ruling on the admissibility of the Richfield shooting incident and denying Brown’s Brady claim for failure to meet the requirement that the evidence be material. We granted Brown’s subsequent motion to vacate the stay and reinstated the direct appeal, and then consolidated the direct and postcon-viction appeals.
Brown now argues that he is entitled to a new trial for five reasons. First, the trial court violated his right to a public trial. Second, the trial court committed reversible error when it admitted evidence of the Richfield shooting incident. Third, the trial court committed plain error in its aiding-and-abetting jury instruction. Fourth, the trial court committed plain error when it admitted expert gang testimony. Fifth, the trial court erred in denying a motion for a new trial after the State failed to disclose impeaching evidence. Because the facts of this case do not implicate the right to a public trial, the trial court did not err in its evidentiary rulings or its jury instructions, and the undisclosed impeachment evidence was not material, we affirm.
I.
We begin with Brown’s argument that his constitutional right to a public trial *616was violated. Brown asserts that the act of locking the courtroom during jury instructions implicated his right- to a public trial. Based on that assertion, Brown contends that the trial court was required to make findings in accordance with Waller v. Georgia, 467 U.S. 3.9, 45, 104 S.Ct. 2210, 81 L.Ed.2d 31 (1984).3 Brown contends that, because the trial court failed to make such findings and because the act of locking the courtroom during jury instructions was not narrowly tailored to an overriding interest, he is entitled to a new trial. We conclude that the act of locking the courtroom doors during jury instructions did not implicate Brown’s right to a public trial.
Whether the right to a public trial has been violated is a constitutional issue that we review de novo. State v. Mahkuk, 736 N.W.2d 675, 684 (Minn.2007). Both the Sixth Amendment to the United States Constitution and Article I, Section 6, of the Minnesota Constitution provide that “the accused shall enjoy the right to a ,... public trial.” Denials of the public trial guarantee constitute structural error not subject to harmless error review. State v. Bobo, 770 N.W.2d 129, 139 (Minn.2009).
The purpose of the public trial guarantee is “ ‘for the benefit of the accused; that the public may see he is fairly dealt with and not unjustly condemned, and that the presence of interested spectators may keep his triers keenly alive to a sense of their responsibility and to the importance of their functions.’ ” Waller, 467 U.S. at 47-48, 104 S.Ct. 2210 (quoting Gannett Co. v. DePasquale, 443 U.S. 368, 380,- 99 S.Ct -. 2898, 61 L.Ed. 2d 608 (1979)) (holding that the total closure of a courtroom from all spectators or press during a pretrial suppression hearing violated the Sixth Amendment’s public trial guarantee). In addition, “a public trial encourages witnesses to come forward and-discourages perjury.” Id. at 46, 104 S.Ct. 2210. Almost twenty years before Waller, we affirmed the right to a public trial by explaining:
In our opinion, the constitutional mandate contemplates that an accused be afforded all possible benefits that a trial open to the public is designed to assure. Unrestricted public scrutiny of judicial action' is a meaningful assurance to an accused that he will be dealt with justly, protected hot only against gross abuses of judicial power but also petty arbitrariness. The presence of an audience does have a wholesome effect on trustworthiness since witnesses are less likely to testify falsely before a public gathering. Further, the possibility that some spectator drawn to the trial may prove to be *617an undiscovered witness in possession of critical evidence cannot be ignored. It is not unrealistic even in this day to believe that public inclusion affords citizens a form of legal education and hopefully promotes confidence in the fair administration of justice.
State v. Schmit, 273 Minn. 78, 86-88, 139 N.W.2d 800, 806-07 (1966) (footnotes omitted) (holding that the closure of a trial to all spectators but “the bar and press” could not be constitutionally justified despite the potentially lurid nature of a sodomy trial). The Supreme Court has held that the public trial guarantee applies to all phases of trial, including pretrial suppression hearings and jury voir dire. See Presley v. Georgia, 558 U.S. 209, 130 S.Ct. 721, 723-24, 175 L.Ed.2d 675 (2010); Waller, 467 U.S. at 46-48, 104 S.Ct. 2210; see also State v. Lawrence, 167 N.W.2d 912, 915 (Iowa 1969) (“All authorities agree that, in the absence of legitimate reasons for limiting public attendance in criminal trials, the concept of public trial includes the entire trial from the impaneling of the jury to the rendering of its verdict.”).
Not all courtroom restrictions implicate a defendant’s right to a public trial. See State v. Lindsey, 632 N.W.2d 652, 660-61 (Minn.2001). In Lindsey, we held that the act of excluding two minors from observing a criminal trial was “not a true closure, in the sense of excluding all or even a significant portion of the public from the trial.” Id. at 660. In reaching our holding in Lindsey, we concluded the closure in question was so trivial that it did not implicate Lindsey’s right to a public trial, thereby eliminating any need to conduct a Waller analysis.4 Id. at 660-61. We identified several factors that led us to conclude that the closure “ ‘was too trivial to amount to a violation of the [Sixth] Amendment.’” Id. at 660 (alteration in original) (quoting Peterson v. Williams, 85 F.3d 39, 42 (2d Cir.1996)). These factors included: that the courtroom was never “cleared of all spectators”; that the trial remained open to the general public and the press; that there was no period of the trial in which members of the general public were absent during the trial; and that at no time was the defendant, his family, his friends, or any witness improperly excluded. Id. at 661.
More recently, in State v. Caldwell, 803 N.W.2d 373, 390 (Minn.2011), we rejected Caldwell’s claim that his right to a public trial was violated. We explained that “the district court excluded only Caldwell’s mother when she repeatedly disrupted court proceedings, and never excluded all spectators from the courtroom even when the court locked the courtroom doors [before instructing the jury].” Id.
Consistent with our analysis in Lindsey and Caldwell, we reject Brown’s claim that the trial court violated his right to a public trial. While the trial court did lock the courtroom doors during jury instructions, the courtroom was never cleared of all spectators, and the judge in fact told the *618people in the courtroom that they were “welcome to s[t]ay.” The trial remained open to the public and press already in the courtroom and the trial court never ordered the removal of any member of the public, the press, or the defendant’s family.5 In addition, the jury instructions did not comprise a proportionately large portion of the trial proceedings. All of these circumstances, taken together, convince us that the trial court’s conduct did not implicate Brown’s right to a public trial.
Our holding that the closure here did not implicate Brown’s right to a public trial notwithstanding, we caution that the act of locking courtroom doors during jury instructions creates the appearance that Minnesota’s courtrooms are closed or inaccessible to the public. Trial courts should therefore commit such acts carefully and sparingly. See United States v. Scott, 564 F.3d 34, 39 (1st Cir.2009) (explaining that “a procedure such as [locking the doors during jury instructions] should be employed only carefully and sparingly, in order to avoid even the appearance that our nation’s courtrooms are closed or inaccessible to the public”). To facilitate appellate review in future cases, we conclude the better practice is for the trial court to expressly state on the record why the court is locking the courtroom doors.
II.
Brown next argues that the trial court committed reversible error when it admitted evidence of the Richfield shooting incident. Specifically, Brown contends that the Richfield shooting evidence was not “inextricably intertwined” with Miller’s murder because the two crimes were neither temporally nor causally related. Because we conclude that the trial court properly admitted the Richfield shooting evidence under Minn. R. Evid. 404(b), we need not, and do not, decide whether the Richfield shooting evidence was temporally or causally related to Miller’s murder.
At Brown’s Rasmussen hearing, the defense moved to exclude evidence related to the Richfield shooting incident, arguing that the evidence involved a previous bad act that was inadmissible under State v. Spreigl, 272 Minn. 488, 139 N.W.2d 167 (1965) and Minn. R. Evid. 404(b). The State argued that the evidence was admissible as “inextricably intertwined” evidence because the State’s forensic expert would testify that the .9mm bullet casing found in the Richfield shooting matched the .9mm bullet casing found near Miller’s body, thereby linking Brown to the scene of the murder. In the alternative, the State argued that the evidence was admissible under Minn. R. Evid. 404(b) to prove identity, opportunity, and lack of mistake or accident.
The trial court agreed with the State and ruled the Richfield shooting evidence was inextricably intertwined with Miller’s murder and admissible “under the eviden-tiary rules.” The trial court emphasized that the Richfield shooting evidence was being offered “for the limited purpose of connecting [Brown] to possession of one of the guns that was used at the scene of the homicide itself, by way of forensic evidence, that linked a shell easing found at the scene of the Richfield crime ... to a shell casing that was found at the scene of the homicide.”6
*619We review evidentiary rulings for an abuse of discretion. State v. Riddley, 776 N.W.2d 419, 424 (Minn.2009). In order to prevail on a claim that a trial court improperly admitted evidence under Rule 404(b), the defendant “has the burden to show the admission was both erroneous and prejudicial.” Id.
We have long held that “[t]he general rule in a criminal case is that evidence which in any manner shows or tends to show that the accused has committed another crime independent of that for which he is on trial is inadmissible.” State v. Sweeney, 180 Minn. 450, 455, 281 N.W. 225, 227 (1930). In Sweeney, we explained that the general rule, however, does not prohibit the admission of other-crime evidence that “tends to establish (1) motive, (2) intent, (3) absence of mistake or accident, (4) the identity of the accused, (5) sex crimes, (6) a common scheme or plan embracing the commission of similar crimes so related to each other that proof of one or more of such tends to establish the accusation.” Id. at 455, 231 N.W. at 227. In considering whether evidence of a defendant’s previous possession of a gun was admissible under an exception to the general rule, we have acknowledged that “evidence of [previous] possession of a gun is not rendered inadmissible merely because it may indicate or have an ‘incidental tendency5 to implicate the defendant in unrelated offenses.” State v. Wofford, 262 Minn. 112, 119, 114 N.W.2d 267, 272 (1962).
We have since incorporated the general rule and exceptions discussed in Sweeney into Minn. R. Evid. 404(b). Rule 404(b) reads in relevant part:
Evidence of another crime, wrong, or act is not admissible to prove the character of a person in order to show action in conformity therewith. It may, however, be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident. In a criminal prosecution, such evidence shall not be admitted unless 1) the prosecutor gives notice of its intent to admit the evidence consistent with the rules of criminal procedure; 2) the prosecutor clearly indicates what the evidence will be offered to prove; 3) the other crime, wrong, or act and the participation in it by a relevant person are proven by clear and convincing evidence; 4) the evidence is relevant to the prosecutor’s case; and 5) the probative value of the evidence is not outweighed by its potential for unfair prejudice to the defendant.
Minn. R. Evid. 404(b).
For the following reasons, we conclude that the trial court did not abuse its discretion when it concluded that the Richfield shooting evidence was admissible “under the rules of evidence.” First, evidence of Brown’s admitted participation in the Richfield shooting incident was probative on the issue of the identity of the perpetrator in the murder case because a .9mm bullet casing found at the Richfield shooting matched the .9mm bullet casing found near Miller’s body. See Minn. R. Evid. 402. Second, the videotape of Brown leaving jail wearing a white tank top and large necklace 12 hours before Miller’s murder was probative on the relevant issues of identity and opportunity. Id. Third, the fact that the evidence in question incidentally implicated Brown in another crime did not render the evidence inadmissible. See Minn. R. Evid. 404(b) (allowing the admission of other-crime evidence that is offered to prove identity or opportunity); Wofford, 262 Minn. at 118, 114 N.W.2d at 271 (holding that “[t]he state may prove all relevant facts and circumstances which *620tend to establish any of the elements of the offense with which the accused is charged, even though such facts and circumstances may prove or tend to prove that the defendant committed other crimes”). Fourth, the State complied with the notice requirements set forth in Rule 404(b). Fifth, the probative value of the evidence in question outweighed any risk of unfair prejudice, especially when the court gave the jury a cautionary instruction in connection with the evidence. Because the Richfield shooting evidence was properly admitted under Minn. R. Evid. 404(b), we reject Brown’s argument that admission of the evidence constituted reversible error.
III.
Brown next argues that the trial court committed plain error when it admitted Sergeant Hauge’s expert gang testimony. Sergeant Hauge testified for the State as a gang expert and described Minneapolis gangs, including the Shotgun Crips: them participation in criminal activities; and some rituals and inner workings of gang memberships and hierarchies.
Brown did not object to the expert gang testimony at trial. We review the admission of unobjected-to gang expert testimony for plain error. State v. Martinez, 725 N.W.2d 733, 738-39 (Minn.2007). Under plain-error analysis, Brown must show that: (1) there was error; (2) that was plain; and (3) his substantial rights were affected. State v. Griller, 583 N.W.2d 736, 740 (Minn.1998). “An error is ‘plain’ if it is clear or obvious.” State v. Kuhlmann, 806 N.W.2d 844, 853 (Minn.2011) (quoting State v. Jones, 753 N.W.2d 677, 686 (Minn.2008)). “If these three prongs are met, the reviewing court then assesses whether it should address the error to ensure the fairness and integrity of the judicial proceedings.” State v. Gomez, 721 N.W.2d 871, 880 (Minn.2006). The defendant has the burden of proof on the third element of the test, and it is considered a “heavy burden.” Griller, 583 N.W.2d at 741. If we conclude that any prong of the plain error analysis is not satisfied, we need not consider the other prongs. Montanaro v. State, 802 N.W.2d 726, 732 (Minn.2011).
Under Minn. R. Evid. 702, an expert witness may testify if the opinion proffered “will assist the trier of fact to understand the evidence or to determine a fact in issue.” Minn. R. Evid. 702. General testimony about the workings of a gang or the types of activities in which gangs engage is not considered testimony that reaches an ultimate legal conclusion, and is often necessary to prove that a crime was committed “for the benefit of a gang.” State v. Jackson, 714 N.W.2d 681, 692 (Minn.2006). We have previously affirmed the admission of gang expert testimony similar to that given by Sergeant Hauge. State v. McDaniel, 777 N.W.2d 739, 748-49 (Minn.2010). Having affirmed the admission of similar gang expert testimony, we are unable to conclude that the alleged error in this case was clear and obvious. We therefore conclude that the trial court did not commit plain error in admitting Sergeant Hauge’s expert gang testimony.
IV.
Brown also argues that the trial court’s aiding-and-abetting jury instructions constituted plain error because the instructions as given “allowed the jury to find Brown guilty if it found that he was intentionally present at the murder without also finding that it was Brown’s intent that his presence aid or encourage the murder.” We disagree.
Brown was charged with aiding and abetting four counts of murder under MinmStat. § 609.05, subd. 1. “A person is criminally liable for a crime committed by *621another if the person intentionally aids, advises, hires, counsels, or conspires with or otherwise procures the other to commit the crime.” Id. Mere presence at the scene of a crime does not give rise to accomplice liability. State v. Ostrem, 535 N.W.2d 916, 924 (Minn.1995).
At the conclusion of closing arguments, the trial court gave the following instruction on the elements of aiding and abetting murder:
Now, a person is guilty of a crime if he acts alone in commission of that crime or if he intentionally aid[s], advises, counsels or conspires with others to commit that crime.
In order to aid and abet others in the commission of a crime, it is necessary that the Defendant voluntarily associate himself with and participate in the criminal venture and that he do or say something to help the criminal venture succeed.
If you find that the State has shown that the Defendant played some knowing role in the commission of the crime or crimes and made no reasonable efforts to pre[v]ent the crime or crimes before the crime was committed, the Defendant is guilty of aiding and abetting in the commission of the crime or crimes.
The phrase, knowing role, here can include aiding, advising, hiring, [counseling], conspiring with or procuring another to commit a crime.
A person’s presence does constitute aiding and abetting if it is done intentionally and if it also aid[s] or encourages the commission of the crime to any degree. However, something more than mere presence, knowledge, inaction or passive acquiescence is required.
A person’s presence, companionship and conduct after an offense are relevant circumstances from which a person’s criminal intent may be inferred.
Brown did not object to the jury instructions at trial. We review unobject-ed-to jury instructions for plain error. State v. Laine, 715 N.W.2d 425, 432 (Minn.2006).
We conclude that the trial court did not err in giving the aiding-and-abetting instructions. Brown’s reliance on Mahkuk, in which we concluded the trial court improperly eliminated the intent requirement for accomplice liability, is misplaced. 736 N.W.2d at 682-83. In Mahkuk, the trial court used permissive language that instructed the jury it “could” consider presence in such a manner that it eliminated the State’s burden to prove intent. Id. Here, the jury was instructed that the State had the burden to prove all of the elements of the offense charged by proof beyond a reasonable doubt, and no such permissive language was used. We therefore conclude that, reading the instructions as a whole, the instructions did not relieve the State of its burden of proof on the elements of aiding and abetting murder, and therefore the trial court did not err in its jury instruction, much less commit plain error.
V.
Finally, Brown argues that he is entitled to a new trial because the State failed to disclose a plea agreement between State witness C.W. and another county attorney’s office. The State concedes that it did not disclose the plea agreement before the conclusion of trial, but argues that a new trial is not justified because the undisclosed impeachment evidence was not material.
We review a postconviction court’s decision to deny a new trial for an abuse of discretion. Wieland v. State, 457 *622N.W.2d 712, 714 (Minn.1990). We review questions of law de novo. Leake v. State, 737 N.W.2d 581, 535 (Minn.2007).
A failure by the State to disclose material, exculpatory evidence justifies a new trial. Brady v. Maryland, 373 U.S. 83, 87-88, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963). More specifically, “suppression by the prosecution of evidence favorable to an accused upon request violates due process where the evidence is material either to guilt or to punishment, irrespective of the good faith or bad faith of the prosecution.” Id. at 87, 83 S.Ct. 1194. To establish a Brady violation, it must be true that: (1) the evidence at issue is favorable to the accused, either because it is exculpatory or it is impeaching; (2) the evidence was willfully or inadvertently suppressed by the State; and (3) prejudice to the accused resulted. Pederson v. State, 692 N.W.2d 452, 459 (Minn.2005). A Brady violation, however, only requires reversal of a conviction “if the evidence is material in the sense that its suppression undermines confidence in the outcome of the trial.” United States v. Bagley, 473 U.S. 667, 678, 105 S.Ct. 3375, 87 L.Ed.2d 481 (1985); Giglio v. United States, 405 U.S. 150, 154, 92 S.Ct. 763, 31 L.Ed.2d 104 (1972).
We conclude that the postconviction court did not abuse its discretion in declining to order a new trial. Although the plea deal between C.W. and the other county attorney’s office constituted impeachment evidence, this undisclosed impeachment evidence was not material because its suppression does not undermine our confidence in the outcome of the trial. C.W. was impeached with five felony convictions that were all disclosed on the record and his plea agreement with the Hen-nepin County Attorney’s Office that was more favorable than the plea agreement reached with the other county attorney’s office. Thus, even if the State had timely disclosed C.W.’s plea agreement with the other county attorney’s office and Brown had been able to exploit that plea agreement to its full potential, it would not have changed our confidence in the outcome of the trial.
In sum, we affirm Brown’s conviction because the facts of this case do not implicate the right to a public trial, the trial court did not err in its evidentiary rulings or its jury instructions, and the undisclosed impeachment evidence was not material.
Affirmed.
. The facts of the reckless-discharge-of-a-firearm case are as follows. On June 23, 2008, Brown was driving a vehicle that was stopped at a stoplight in Richfield, Minnesota, when he was approached by several individuals and threatened. Brown then fired a handgun into the air and drove away. Brown was arrested July 1, 2008, subsequently pled guilty to recklessly discharging a firearm, and was released from jail on the afternoon of August 28, 2008, approximately 12 hours before Miller was killed.
. The reduced sentence was 20-months imprisonment stayed for 3 years, which reflected downward durational and dispositional departures from the presumptive 26-month executed sentence.
. The right to a public trial is not absolute and the analysis set forth in Waller, 467 U.S. at 45, 104 S.Ct. 2210, explains the process for determining whether the right to a public trial must give way. In accordance with Waller, we have explained that the party seeking to close the hearing must advance an overriding interest that is likely to be prejudiced; the closure must be no broader than necessary to protect that interest; and the court must consider reasonable alternatives to closing the hearing. State v. Mahkuk, 736 N.W.2d 675, 684-85 (Minn.2007). To ensure meaningful appellate review of Waller issues, courts are required to " ‘make[ ] findings adequate to support the closure.’ ” Id. at 685 (alteration in original) (quoting Waller, 467 U.S. at 48, 104 S.Ct. 2210); see State v. Fageroos, 531 N.W.2d 199, 203 (Minn.1995) (remanding for a hearing to allow the trial court an opportunity to make a better record in support of its decision to close the trial); State v. McRae, 494 N.W.2d 252, 260 (Minn.1992) (holding that a new trial was required when the stated explanation for the closure would not satisfy Waller and other constitutional violations were alleged). We note, with some concern, that the trial court in this case did not provide any explanation as to why the courtroom doors were locked during the time the jury was being instructed.
. Brown contends that Mahkuk, 736 N.W.2d 675, rather than Lindsey controls the outcome of this case. We disagree. In Mahkuk, the State did not argue that the trial court’s decision to remove identified gang members from the courtroom during the testimony of certain lay witnesses was so trivial as to not violate Mahkuk’s Sixth Amendment right to a public trial. Id. at 684-85. Instead, the State cited a federal court decision that had held that partial courtroom closures (orders that ex-eluded some but not all of the public), required a substantial reason, not an overriding interest for the exclusion of the identified gang members. Id. at 685. We rejected the State's argument, explaining that, unlike the federal courts, we had "not applied different tests to complete versus partial closures.’’ Id. Nothing in Mahkuk called into question our conclusion in Lindsey that some trial court actions are so trivial that they do not implicate a defendant's right to a public trial.
. Brown claims that because the doors were locked, any family member or friend that tried to enter the courtroom during the jury instructions was prevented from doing so. However, nothing in the trial court or post-conviction court record provides factual support for any claim that any particular person was denied entrance.
. The Rasmussen hearing transcript is not in the record. The quotation comes from the postconviction court’s order denying relief, *619however, and neither party disputes its accuracy.