At 10:00 p.m. on the evening of August 11, 1998, Kansas City police executed a warrant to search the home of David Do-ran for drugs and other contraband, using a tactic called “dynamic entry.” Officer Ty Grant, serving as “ram officer,” yelled “Police, search warrant,” and immediately hit the front door with his ram, breaking in on the third hit. Officer Mark Sumpter as point man entered the house before its occupants had time to answer the door. When Sumpter reached the kitchen doorway, he saw Doran running toward him pointing a handgun. Sumpter testified that he yelled, “Police, search warrant, get down,” and fired when Doran did not lower his weapon. Doran was hit twice, sustaining serious injuries. He commenced this action under 42 U.S.C. § 1983, asserting Fourth Amendment damage claims against Officer Sumpter for use of excessive force; the investigating officer, Wesley Williamson, for an illegal warrant search; Officer Grant for illegal entry; Sergeant Eric Greenwell for failure to supervise Grant; and the Board of Police Commissioners for failure to train its officers regarding the Fourth Amendment restrictions on no-knock entries and for deliberate indifference to a custom and practice of no-knock entries.
At trial, Doran testified he was asleep when he heard the ramming. Thinking the noise was a break-in or a fight on the front porch, he grabbed a pistol from under his pillow, ran into the kitchen, saw laser lights and realized it was the police, and bent to set his gun on the floor when he was shot. After a four-day trial, the jury found in favor of Officer Sumpter, rejecting Doran’s excessive force claim. However, the district court ruled as a matter of law that exigent circumstances did not justify the no-knock entry. As a result, the jury instructions on the illegal entry claim against Officer Grant and the failure-to-train claim against Sergeant Greenwell virtually directed a verdict in favor of Doran on those claims. The jury returned a verdict in excess of two million dollars for Doran on those claims and on his claims against the Board, finding that Doran’s injuries were the direct result of the Fourth Amendment violations. The district court entered judgment on this verdict. Grant, Greenwell, and the Board appeal, arguing inter alia that exigent circumstances justified the no-knock entry. We agree and therefore reverse.
I. Background.
In July 1998, Kansas City Police received an anonymous tip about criminal activity allegedly occurring at the Doran home. The tipster alleged:
• that methamphetamine was being manufactured at the house to be searched;
• that Doran was selling crack cocaine and methamphetamine at the front door throughout the day;
• that drugs were stored in dresser drawers throughout the house;
• that guns were kept in the bedroom; and
• that Doran’s 26-year-old son Joseph lived in the house and had recently been arrested for possessing a sawed-off shotgun.
Narcotics Detective Wesley Williamson verified the house’s location, determined that cars parked at that location were registered to the Doran family, and collected bags of trash in front of the residence. In the trash, he found fifty sandwich bags with the corners cut out, a common way *961for traffickers to package and distribute narcotics; methamphetamine residue in two plastic bags, three plastic sandwich bag corners, and a pill bottle; an empty box of a “Dristan” product that contains pseudoephedrine, often used in the manufacture of methamphetamine; and mail tending to confirm that the trash belonged to the Dorans. Detective Williamson recited these facts in a warrant application and obtained a warrant to search the Do-ran home.
The task of executing the warrant was assigned to the Police Department’s Street Narcotics Unit, a specialized unit whose primary function is to execute search warrants, usually on drug houses. Sergeant Greenwell was in charge of the Unit’s entry team. Before executing the warrant, Greenwell reviewed the warrant and warrant affidavit, learning about the illegal activity alleged in the anonymous tip. Sergeant Greenwell and Detective Williamson then drove by the Doran house to verify its location and to “determine any tactical concerns.” Based on this information and his experience with methamphetamine labs, Sergeant Greenwell concluded that this would be a high-risk entry and instructed his team to make a dynamic entry.
On the evening of August 11, the entry team gathered at an assembly point a few blocks from the Doran home. Because of the hazards associated with methamphetamine labs, Greenwell arranged for a fire department pumper and an ambulance to wait at the assembly point. Members of the entry team other than Officer Grant wore respirators to reduce the risk from chemical fumes. After Sergeant Green-well briefed the entry team, the team proceeded to Doran’s house and executed the warrant. Doran was shot soon after Officer Sumpter entered the house. The police completed the search after tending to Doran, finding one ounce of marijuana in the son’s room but neither a methamphetamine lab nor other illegal drugs. Doran was not charged with an offense. This lawsuit followed.
II. The District Court’s Rulings and the Record on Appeal.
Prior to trial, all defendants moved for summary judgment on Doran’s various § 1983 claims. As relevant here, the court granted Detective Williamson summary judgment on Doran’s claim of illegal search, concluding that Williamson had sufficiently verified the anonymous tip to have “an objectively reasonable belief in the existence of probable cause for the issuance of a search warrant.” Doran dropped his remaining claim against Williamson for unlawful execution of the warrant. Eliminated as a defendant, Williamson — who by then had become an agent of the federal Bureau of Alcohol, Tobacco, and Firearms — did not testify at trial. The district court denied Officer Sumpter summary judgment on Doran’s excessive force claim. The court also denied Grant, Greenwell, and the Board summary judgment on Doran’s claims relating to the no-knock manner in which the warrant was executed, concluding “there is insufficient evidence of exigent circumstances to justify dispensing with the knock and announce requirement,” and there were material fact disputes over whether the entry team announced, knocked, and waited an appreciable period before entering.
Though the district court reserved a final ruling on Doran’s knock-and-announce claims because of potential fact disputes, the court properly recognized that the question of exigent circumstances, like the ultimate issue of Fourth Amendment reasonableness, is an issue of law for the court. See United States v. Cooper, 168 F.3d 336, 339 (8th Cir.1999); United States v. Mattison, 153 F.3d 406, 410 (7th Cir.1998). Therefore, both before and during *962the trial, the district court excluded evidence that was relevant to the question of exigent circumstances, even if it was part of the summary judgment record on the issue, if it was either unduly prejudicial or not relevant to fact issues to be decided by the jury. For example, because the court excluded evidence tending to challenge the lawfulness of the valid search warrant, the warrant and warrant affidavit were not offered at trial. Similarly, the police “DRAGNET” report summarizing the anonymous tip was not admitted into evidence because it contained a potentially prejudicial reference to the son’s alleged arrest for possession of a sawed-off shotgun.
The court made its final ruling on the exigent circumstances issue during the instructions conference held at the close of the trial evidence. Consistent with its pretrial summary judgment ruling, the district court “ruled as a matter of law that there were not exigent circumstances which permitted the waiver of the knock or wait rule, and we’ll not be submitting that to the jury.” In making .this ruling, the court declared that it considered “all of the evidence which is admissible during the course of trial, as well as Plaintiffs Exhibit 8 [the DRAGNET tip report] ... [and] all of the evidence that, in fact, has been presented to me.” Neither party objected to the court considering evidence that was only presented during pretrial motion proceedings to decide the legal issue of whether exigent circumstances justified the no-knock entry. Indeed, given the need to withhold irrelevant or unduly prejudicial information from the jury’s consideration, we agree with the district court’s approach to this issue, though our task on appeal would be easier if the court had defined more precisely what evidence not in the trial record “has been presented to me.” Therefore, we will review the same record that the district court considered in making its legal determination of no exigent circumstances.1
III. The Controlling Legal Standard.
In Wilson v. Arkansas, the Supreme Court held for the first time that the “common-law ‘knock and announce’ principle forms a part of the reasonableness inquiry under the Fourth Amendment.” 514 U.S. 927, 929, 115 S.Ct. 1914, 131 L.Ed.2d 976 (1995). The Court cautioned, however, that “[t]he Fourth Amendment’s flexible requirement of reasonableness should not be read to mandate a rigid rule of announcement that ignores countervailing law enforcement interests.” Id. at 934, 115 S.Ct. 1914. The Court noted examples of circumstances that may justify an unannounced entry, such as a threat of physical violence or the likely destruction of evidence, but declined to “attempt a comprehensive catalog of the relevant countervailing factors.” Id. at 935-36, 115 S.Ct. 1914.
The Court has applied this general principle in three subsequent eases. In Richards v. Wisconsin, the Court rejected a state supreme court’s decision to adopt a blanket exception to the Fourth Amendment’s knock-and-announce requirement when police execute a search warrant in a felony drug investigation. 520 U.S. 385, 388, 117 S.Ct. 1416, 137 L.Ed.2d 615 (1997). Though acknowledging “that felony drug investigations may frequently present circumstances warranting a no-knock entry,” the Court held that a case-*963by-case analysis of the facts of a particular entry is nonetheless required:
In order to justify a “no-knock” entry, the police must have a reasonable suspicion that knocking and announcing their presence, under the particular circumstances, would be dangerous or futile, or that it would inhibit the effective investigation of the crime by, for example, allowing the destruction of evidence. This standard — as opposed to a probable-cause requirement — strikes the appropriate balance between the legitimate law enforcement concerns at issue in the execution of search warrants and the individual privacy interests affected by no-knock entries. This showing is not high ....
Id. at 394, 117 S.Ct. 1416 (citations omitted). The Court went on to hold that the no-knock entry at issue was reasonable and affirmed the judgment of the state court.
In United States v. Ramirez, the Court reversed a Ninth Circuit holding that more than a “mild exigency” must be shown to justify a no-knock entry in which property is destroyed. 523 U.S. 65, 69-70, 118 S.Ct. 992, 140 L.Ed.2d 191 (1998). In Ramirez, a reliable confidential informant told police that he had seen a violent prison escapee at the Ramirez home and that Ramirez might have a stash of guns and drugs in his garage. The Court held that the police “certainly had a ‘reasonable suspicion’ that knocking and announcing their presence might be dangerous to themselves or to others,” so it was “clearly reasonable” to break a garage window during the no-knock entry. Id. at 71-72, 118 S.Ct. 992.
Finally, in United States v. Banks, the Court rejected the Ninth Circuit’s “four-part scheme for vetting knock-and-announce entries.” 540 U.S. 31, 41, 124 S.Ct. 521, 157 L.Ed.2d 343 (2003). In Banks, police executing a warrant to search for cocaine arrived at the premises to be searched with no reasonable suspicion justifying a no-knock entry and waited only fifteen or twenty seconds after the initial knock before entering. Emphasizing again that the totality of the circumstances must be examined to determine whether exigent circumstances exist, the Court held that the risk of imminent drug disposal was an exigency that justified the forcible entry. Id. at 40, 124 S.Ct. 521.2
IV. Discussion.
The district court explained the bases for its exigent circumstances ruling in an opinion denying defendants’ post trial motions. The court emphasized that the police did not obtain a no-knock warrant to search the Doran home. The court also cited the following additional factors as supporting its conclusion that exigent circumstances did not justify Officer Grant’s no-knock entry:
• The facts known to the police as they approached the Doran house were the same facts known when they applied for the warrant.
• The anonymous tip did not come from a reliable confidential informant, and the information was not verified or corroborated.
• The tip that drug sales were occurring at the Doran house was not corroborated by a controlled buy or surveillance.
• The trash search uncovered drug residue, but no evidence linked the trash to Doran’s house.
*964• The police did not check the criminal history of Doran and his wife, which would have revealed no prior arrests.3
• The allegation that Doran’s son was recently arrested for possession of a sawed-off shotgun was not verified.
• The entry team conducted no surveillance to determine if the son was home or lights were on before the nighttime entry.
• Officer Grant routinely operated the ram as he did in this case — announce “police, search warrant,” and simultaneously break in with the ram without otherwise knocking or waiting for a response.
We review the district court’s exigent circumstances ruling de novo. Cooper, 168 F.3d at 339. The district court’s analysis of the exigent circumstances issue is contrary to the Supreme Court’s knock- and-announce decisions in significant respects. First, the district court erred in emphasizing the absence of no-knock authority in the search warrant. As the Court said some years ago in Dalia v. United States, 441 U.S. 238, 257, 99 S.Ct. 1682, 60 L.Ed.2d 177 (1979):
Nothing in the language of the Constitution or in this Court’s decisions interpreting that language suggests that ... search warrants also must include a specification of the precise manner in which they are to be executed. On the contrary, it is generally left to the discretion of the executing officers to determine the details of how best to proceed with the performance of a search authorized by warrant — subject of course to the general Fourth Amendment protection “against unreasonable searches and seizures.”
In Richards, the Supreme Court confirmed this principle when it upheld a no-knock entry based on what the officers encountered when executing the warrant, even though the issuing magistrate had denied a request for a no-knock warrant. 520 U.S. at 395-96 & n. 7, 117 S.Ct. 1416; see Banks, 540 U.S. at 36-37, 124 S.Ct. 521. Of course, state law may require, by statute or judicial decision, that law enforcement officers who have reason to believe that exigent circumstances justify a no-knock entry include a request for that authority in the warrant application. See Davis v. State, 383 Md. 394, 859 A.2d 1112, 1124-26 (2004) (collecting conflicting authorities from various States). But for Fourth Amendment purposes, the relevant question is whether the police have reasonable suspicion of exigent circumstances at the time they execute the warrant.
Second, the district court erred in emphasizing that the facts known to the police as they approached the Doran house were the same facts known when they applied for the warrant. To be sure, many exigent circumstances cases have turned on facts that unfolded as the police approached the house to be searched, or after they initially knocked. See, e.g., Richards, 520 U.S. at 388-89, 117 S.Ct. 1416. But the Fourth Amendment analysis turns on the totality of the circumstances, including facts gathered by the police before they applied for the warrant. See United States v. Scroggins, 361 F.3d 1075, 1081-82 (8th Cir.2004). The district *965court’s approach would require that the police request no-knock authority whenever the basis for a warrant application might justify a no-knock entry. Such a rule might encourage excessive use of the no-knock tactic and would be contrary to Supreme Court decisions applying the Fourth Amendment’s reasonableness standard. Therefore, if the facts known prior to obtaining the warrant justify a no-knock entry, and if no contrary facts are discern-able to the officers who execute the warrant, the no-knock entry is constitutionally reasonable.
Third, the district court concluded that the prior investigation by “the police” was inadequate and then attributed these inadequacies to the Street Narcotics Unit officers brought in solely to execute the warrant. This analysis of the police conduct in gross would be proper in deciding a motion to suppress evidence in a criminal prosecution of Doran arising out of the search. But § 1983 liability is personal. The question here is whether the conduct of Officer Grant and Sergeant Greenwell was constitutionally unreasonable. The answer to that question must take into account the settled principle that law enforcement officers may rely on information provided by others in the law enforcement community, so long as the reliance is reasonable. See United States v. Hensley, 469 U.S. 221, 232, 105 S.Ct. 675, 83 L.Ed.2d 604 (1985); Baker v. McCollan, 443 U.S. 137, 145-46, 99 S.Ct. 2689, 61 L.Ed.2d 433 (1979); Brown v. Nutsch, 619 F.2d 758, 764-65 (8th Cir.1980). .
Fourth, the district court relied on the fact that Officer Grant “routinely operated the ram as he did in this case.” But Sergeant Greenwell made the decision to make the no-knock entry after evaluating all the circumstances and assigned Officer Grant the role of ram officer. Having been briefed by Sergeant Greenwell, Grant had no constitutional duty to verify that exigent circumstances attended execution of the warrant before carrying out his assignment. Greenwell testified that he often assigned Grant the role of ram officer for high-risk entries. Thus, Grant’s testimony that he employed the dynamic entry tactic whenever he was assigned to be ram officer said nothing about the prevalence or reasonableness of the tactic and did not establish a Fourth Amendment violation.
In addition to these faulty legal premises, the district court’s exigent circumstances analysis gave undue weight to certain portions of the pretrial record, while ignoring others. The court focused on what it considered to be an incomplete investigation to verify the anonymous tip. But the court brushed aside the most significant corroborating evidence — the trash search — because “there was no evidence that the drug residue or the trash bag in which it was found was linked to the Doran residence.” The evidence was that four trash bags were collected from in front of Doran’s house. The bags contained drug residue and pieces of mail addressed to the Dorans. Even if Detective Williamson did not testify that the mail and the drug residue came from the same bag, it was wrong to conclude that the trash search did not corroborate critical aspects of the anonymous tip. The tip reported daily drug sales from the house, suggesting the presence of small quantities of narcotics that are readily disposable; the trash contained multiple sandwich bags with the corners cut. The tip reported on-going manufacture of methamphetamine; the trash contained six different containers with methamphetamine residue. Moreover, the court’s statement that the trash “contained no evidence of any of the chemicals or apparatus used to make methamphetamine” was simply wrong. The trash contained an empty box of a product con-*966taming pseudoephedrine, a methamphetamine precursor. Of course, one box of Dristan does not confirm the presence of a meth lab. But the fact-finding underlying the district court’s exigent circumstances ruling was nonetheless clearly erroneous. The trash analysis tended to show that the anonymous tip was “reliable in its assertion of illegality, not just in its tendency to identify a determinate person.” Florida v. J.L., 529 U.S. 266, 272, 120 S.Ct. 1375, 146 L.Ed.2d 254 (2000).
There remains the question whether exigent circumstances justified Sergeant Greenwell’s decision to use the no-knock method of executing the warrant to search Doran’s house. Before executing the warrant, Greenwell reviewed the warrant and warrant affidavit, interviewed the investigating officer, and drove by the Doran house. This was a reasonable level of research for the head of a team brought in to execute the warrant. Greenwell learned that the house was suspected of harboring a clandestine methamphetamine lab. That fact has justified no-knock entries in prior cases.4 Consistent with these cases, Greenwell testified at trial:
Q. What kind of dangers do you encounter in terms of officer safety when you enter ... what you presume to be a meth lab?
A. Well, besides the obvious danger of drugs and firearms ... you have a lot of added problems .... The chemicals and the types of products that individuals use to manufacture methamphetamine are very volatile, combustible, ha[ve] caused explosion, fire, things of that nature.
We carry specific types of equipment to help make our entry safer ... and we train the [officers] to evacuate if those detectors ... tell us ... the environment is superseding our personal protective equipment.
* ❖ * ❖ % *
Q. [H]ave you ever been in a lab where somebody tried to destroy it?
A. Yes. We’ve been in a situation before where suspects could flee and knock over parts of the lab.... Sometimes they destroy the lab in an attempt to cause harm to us on the entry team and sometimes trying to destroy evidence ....
Q. Okay. Is there any kind of gas danger?
A. Gas, there’s a phosphine gas danger .... [I]f they cook the product too long, [methamphetamine labs] can emit phosphine gas, which is highly deadly.
Greenwell also learned that ongoing drug street sales had been reported and that numerous weapons were kept in the house, facts that have justified no-knock entries in numerous cases.5 Finally, he learned that Doran’s son had recently been arrested for possession of a sawed-off shotgun. Though this tip later turned out to be *967inaccurate, reasonable suspicion that an armed and potentially dangerous resident will be present has frequently justified no-knock entries.6
Taken together, as we must do in assessing the totality of the circumstances, we conclude that this information, plus Williamson’s trash run, established a reasonable suspicion of exigent circumstances. The burden to show a reasonable suspicion of exigent circumstances “is not high.” Richards, 520 U.S. at 394, 117 S.Ct. 1416. In this case, the head of a team brought in to execute the warrant learned that the house to be searched was suspected of harboring a clandestine methamphetamine lab, a stash of drugs for on-going street sales, multiple weapons, and a potentially violent resident. It was constitutionally reasonable for Sergeant Greenwell, the head of this special team, to rely on what he learned from reading the warrant documents and from interviewing the investigating officer, Detective Williamson. It was constitutionally reasonable for Officer Grant to perform his assigned duty as ram officer as he had been trained to carry out that task in cases of high-risk dynamic entries. “In making the determination of whether the Fourth Amendment has been violated by a failure to knock and announce, we must remember reasonableness is our polestar.” United States v. Mendoza, 281 F.3d 712, 717 (8th Cir.), cert.. denied, 537 U.S. 1004, 123 S.Ct. 515, 154 L.Ed.2d 401 (2002). Accordingly, the unlawful entry claim against Grant and the unlawful entry and failure-to-train claims against Greenwell should not have been submitted to the jury.
Because the individual defendants did not violate Doran’s constitutional rights, his failure-to-train and custom and practice claims against the Board of Police Commissioners should not have been submitted to the jury. See Roach v. City of Fredericktown, 882 F.2d 294, 297-98 (8th Cir.1989). The judgment of the district court is reversed, and the case is remanded with directions to dismiss the complaint.
. For this reason, we grant appellee's motion to take judicial notice of the search warrant and supporting affidavit, and appellants’ motion to file a supplemental appendix containing Plaintiff's Exhibit 8, materials presented to and considered by the district court at the summary judgment stage but not admitted at trial.
. The Court noted in Ramirez, 523 U.S. at 73, 118 S.Ct. 992, that its decisions in Wilson and Richards "serve as guideposts in construing” the exigent circumstances exception to 18 U.S.C. § 3109. Accord Banks, 540 U.S. at 42-43, 124 S.Ct. 521. Thus, our contrary statement in United States v. Tavares, 223 F.3d 911, 916 n. 5 (8th Cir.2000), is overruled.
. Regarding Mrs. Doran, who did not testify, the court's statement appears to be based on assertions in various memoranda filed by Do-ran's attorneys, who also filed a motion in limine in September 2002, some three months before trial, seeking an order excluding evidence that Mrs. Doran and her sister "had criminal records involving illegal drugs and/or prostitution.” As the motion in limine was granted, the criminal history facts are not in the record on appeal. It is undisputed that the police investigators did not do criminal history checks on the Dorans and their son prior to obtaining and executing the search warrant.
. See United States v. Tucker, 313 F.3d 1259, 1265-66 (10th Cir.2002) (nighttime execution justified by public safety exigency); United States v. Keene, 915 F.2d 1164, 1168-69 (8th Cir.1990) (destruction of evidence), cert. denied, 498 U.S. 1102, 111 S.Ct. 1001, 112 L.Ed.2d 1084 (1991); United States v. Spinelli, 848 F.2d 26, 29-30 (2d Cir.1988) (public safety); cf. United States v. Walsh, 299 F.3d 729, 733-34 (8th Cir.2002) (warrantless search authorized by public safety exigency), cert. denied, 537 U.S. 1066, 123 S.Ct. 617, 154 L.Ed.2d 554 (2002).
. See United States v. Washington, 340 F.3d 222, 227 (5th Cir.2003), cert. denied, 540 U.S. 1081, 124 S.Ct. 942, 157 L.Ed.2d 757 (2003); United States v. Gambrell, 178 F.3d 927, 928-29 (7th Cir.1999), cert. denied, 528 U.S. 920, 120 S.Ct. 281, 145 L.Ed.2d 236 (1999); Mattison, 153 F.3d at 410-11; United States v. Singer, 943 F.2d 758, 761-63 (7th Cir.1991); State v. Baker, 103 S.W.3d 711, 717-19 (Mo.2003) (en banc).
. See United States v. Nguyen, 250 F.3d 643, 645 (8th Cir.2001); United States v. Gay, 240 F.3d 1222, 1228-29 (10th Cir.2001), cert. denied, 533 U.S. 939, 121 S.Ct. 2571, 150 L.Ed.2d 735 (2001); United States v. Weeks, 160 F.3d 1210, 1213-14 (8th Cir.1998); United States v. Murphy, 69 F.3d 237, 243 (8th Cir.1995), cert. denied, 516 U.S. 1153, 116 S.Ct. 1032, 134 L.Ed.2d 109 (1996).