Affirmed in part, vacated in part, and remanded by published opinion. Judge SHEDD wrote the opinion, in which Chief Judge WILLIAMS joined.
OPINION
While attempting to use a Taser to stop Frederick P. Henry from fleeing arrest, Somerset County (Maryland) Deputy Sheriff Robert Purnell mistakenly drew his firearm, rather than his Taser, from his holster. Not realizing the mistake, Pur-nell then shot and wounded Henry. Consequently, Henry filed this action under 42 U.S.C. § 1983, and Articles 24 and 26 of the Maryland Declaration of Rights, claiming that Purnell violated his right to be free from the use of excessive force during arrest. Purnell moved for summary judgment, arguing that he did not violate Henry’s rights and, in any event, that he is entitled to qualified immunity on the § 1983 claim and Maryland statutory immunity on the state-law claim. The district court denied the motion,
Henry v. Purnell,
I
We have jurisdiction to review “final decisions” of district courts, 28 U.S.C. § 1291, and “a district court’s denial of a claim of qualified immunity, to the extent that it turns on an issue of law, is an appealable ‘final decision’ within the meaning of ... § 1291 notwithstanding the absence of a final judgment.”
Mitchell v. Forsyth,
Qualified immunity shields government officials performing discretionary
*377
functions “from liability for civil damages insofar as their conduct does not violate clearly established statutory or constitutional rights of which a reasonable person would have known.”
Harlow v. Fitzgerald,
When a government official properly asserts qualified immunity, the threshold question that a court must answer is whether the facts, when viewed in the light most favorable to the plaintiff, show that the official’s conduct violated a constitutional right.
Saucier,
The “answer to both
Saucier
questions must be in the affirmative in order for a plaintiff to defeat a ... motion for summary judgment on qualified immunity grounds.”
Batten v. Gomez,
*379 II
With these principles in mind, we begin our
Saucier
analysis by considering the initial question of whether the facts, when viewed in Henry’s favor, show that Purnell used excessive force in arresting him and, therefore, violated his Fourth Amendment right to be free from an unreasonable seizure.
See Graham v. Connor,
A.
The first step in assessing whether Pur-nell violated Henry’s Fourth Amendment right is to determine the relevant facts.
Scott v. Harris,
— U.S. -,
“On October 9, 2003, an arrest warrant was issued for Henry for failing to obey a court order to either pay his child support arrearage or report to a detention center to serve a jail sentence for failure to pay. On October 20, Purnell went to Henry’s last known address in Eden, Maryland, in an attempt to arrest him. The officer discovered Henry at that address but Henry avoided arrest by lying about his identity. Soon thereafter, Purnell learned that the man he had talked to was in fact Henry. Three days later, Purnell noticed Henry in a passing truck, followed him, and pulled into a driveway alongside the truck. Purnell ordered Henry out of the truck. Henry complied but fled before he could be handcuffed. Purnell claims Henry pushed him in the course of escaping; Henry denies that occurred. In any event, Purnell pulled out a Glock .40 caliber handgun and shot the fleeing Henry in the elbow. Henry stopped running and was arrested.
“The parties have stipulated that Pur-nell did not intend to shoot Henry with his handgun. Rather, he intended to unhol-ster and discharge his Taser, a non-lethal device that immobilizes a suspect via an electromuscular disruption. The Taser was holstered on Purnell’s right side, just below his holstered handgun. Purnell has testified on deposition that he reached for the Taser because he felt endangered by Henry’s actions. He asserts that he thought Henry might be running to get a weapon.
“Purnell did not realize he had fired the handgun until after the weapon discharged. He immediately told Henry and another witness at the scene that he had not meant to shoot Henry and that he had grabbed the wrong weapon.”
Henry,
B.
Having identified the relevant facts, we now turn to the question of whether these facts establish that Purnell seized Henry within the meaning of the
*380
Fourth Amendment. “A person is seized by the police and thus entitled to challenge the government’s action under the Fourth Amendment when the officer, by means of physical force or show of authority, terminates or restrains his freedom of movement,
through means intentionally applied.” Brendlin v. California,
— U.S. -,
1.
In
Brower v. County of Inyo,
[I]f a parked and unoccupied police car slips its brake and pins a passerby against a wall, it is likely that a tort has occurred, but not a violation of the Fourth Amendment. And the situation would not change if the passerby happened, by lucky chance, to be a serial murderer for whom there was an outstanding arrest warrant-even if, at the time he was thus pinned, he was in the process of running away from two pursuing constables. It is clear, in other words, that a Fourth Amendment seizure does not occur whenever there is a governmentally caused termination of an individual’s freedom of movement (the innocent passerby), nor even whenever there is a governmentally caused and governmentally desired termination of an individual’s freedom of movement (the fleeing felon), but only when there is a governmental termination of freedom of movement through means intentionally applied.
Id.
at 596-97,
The Court then observed that a roadblock “is designed to produce a stop by physical impact if voluntary compliance does not occur,” and it rejected any inquiry into whether the police subjectively intended for the roadblock to cause the driver to stop on his own before crashing or whether the roadblock was designed to produce a collision.
Id.
at 598,
We think it enough for a seizure that a person be stopped by the very instrumentality set in motion or put in place in order to achieve that result. It was enough here, therefore, that, according to the allegations of the complaint, Brower was meant to be stopped by the physical obstacle of the roadblock' — and that he was so stopped.
Id.
at 599,
2.
We are not presented with a case where police stopped someone by mere happenstance, such as the passerby who is pinned when a police car slips its brake, or by the unintended consequences of an attempted seizure, such as the fleeing suspect who crashes his vehicle. Instead, the undisputed evidence in -the record establishes that Purnell’s specific intent was to stop Henry from fleeing by means of firing a weapon, and Henry was in fact stopped by the very instrumentality (ie., the Glock) that Purnell set in motion. We recognize that Purnell did not intend to use the Glock, but we are also mindful of the
Brower
Court’s admonition that we should not draw too fine a line in determining whether the means that terminate a person’s freedom of movement is the very means that an officer intended. If, as the Court noted, a seizure would occur when a person is stopped by the accidental discharge of a gun that an officer meant to use only as a club, then we believe that a seizure surely occurred here where Pur-nell intended to stop Henry by firing a weapon at him and succeeded in doing so.
9
Accordingly, we affirm the portion of the district court’s order finding that Purnell
*382
seized Henry.
See
C.
Our determination that Purnell seized Henry does not end the inquiry as to whether a Fourth Amendment violation occurred. Rather, we must next decide whether Purnell acted unreasonably because the “Fourth Amendment does not proscribe all state-initiated ... seizures; it merely proscribes those which are unreasonable.”
Florida v. Jimeno,
Typically, the level of.force that a plaintiff claims to be excessive is the level of force that a law enforcement officer intentionally used (regardless, of course, of whether the officer intended the ultimate consequences). However, this case is atypical because Henry’s claim is based on the fact that Purnell shot him with the Glock, which is
not
the level of force that Purnell intended; indeed, Henry has stipulated that Purnell intended to use the Ta-ser and used the Glock only as the result of a mistake.
11
Although we have rejected Purnell’s argument that the fact of his mistake establishes that he did not seize Henry, the fact of the mistake does bear on the question of whether the seizure was nonetheless reasonable because “a mistaken understanding of the facts that is reasonable in the circumstances can render a seizure based on that understanding reasonable under the Fourth Amendment.”
Milstead,
1.
The district court concluded that Purnell was not entitled to summary judgment because of “the existence of disputed facts concerning the objective reasonableness of his belief that he was firing a Taser when he shot Henry with a handgun.” 428 *383 F.Supp.2d at 398. Combining its Fourth Amendment and qualified immunity discussions, the district court explained:
Purnell violated Henry’s Fourth Amendment rights if ... his belief he was using a Taser was objectively unreasonable under the circumstances he was confronting, as he then reasonably perceived them to be. Likewise, these rights were clearly established because under Graham it would have been clear to a reasonable officer that it was unlawful to use deadly force on the basis of an objectively unreasonable belief about the nature of the weapon being discharged.
Id. Although the district court noted that a jury ultimately might agree that Purnell’s conduct was objectively reasonable, 12 it then identified various facts purportedly in dispute that it deemed relevant to the reasonableness of Purnell’s actions:
(1) the nature of the training Purnell had received to prevent incidents like this from happening, (2) whether he acted in accordance with that training, (3) whether he would have discovered that he was holding a handgun rather than a Taser if, as he apparently had been trained to do, he had attempted to flip the thumb safety device on what he thought was the Taser, (4) whether Henry’s trickery in eluding him three days before heightened Purnell’s sense of danger, warranting the need for hurried action, or (5) whether Henry’s earlier trickery angered Purnell, causing him to act with undue haste and inconsistently with his training.
Id. The district court noted in conclusion that “[rjesolution of any disputes about these facts and the effect of the reasonable inferences to be drawn from them must await trial.” Id.
2.
Before Purnell moved for summary judgment, Henry had filed a discovery motion seeking to compel Purnell to produce certain documents that were used by the Somerset County Sheriffs Office, including training materials relating to the Glock and Taser. Purnell objected to producing these documents on relevance grounds. On the day that Purnell filed his summary judgment motion, Henry requested that the district court rule promptly on the discovery motion, asserting that the discovery documents “may prove to be vital” to his summary judgment opposition. Although there was some additional activity involving the discovery motion — including Henry’s request for relief under Rule 56(f) of the Federal Rules of Civil Procedure, which permits a court to deny summary judgment or order a continuance where the party opposing the motion sets forth by affidavit the reasons why that party is unable to present facts essential to justify its opposition — the district court did not rule on the motion until the same day that it denied the summary judgment motion. By separate order, the district court granted the discovery motion, noting: “As reflected in my opinion on defendant’s summary judgment motion, I believe that training materials relating to the Taser are relevant to this litigation.” J.A. 209. Pur-nell appealed the order granting this discovery motion, but we dismissed that portion of the appeal on Henry’s motion.
3.
We have recounted this discovery matter because we believe that its outcome, combined with the district court’s analysis, necessitates a remand of this case for fur
*384
ther proceedings. As we have explained, when a defendant properly asserts qualified immunity as a defense, the plaintiff bears the initial burden of establishing that the defendant violated his constitutional rights. Thus, in this summary judgment proceeding, Henry bore the initial burden of showing that the seizure was unreasonable. Without noting that Henry bore this burden of proof, the district court concluded that several disputed facts bear on the question of objective reasonableness, and it stated that the resolution of these disputed facts “must await trial.”
We believe that the upshot of all of this is that the district court must reassess the issue of whether a constitutional violation occurred in light of the proper burden of proof and the discovery materials that it ordered Purnell to produce, and it must do so before moving this case forward.
See Scott,
Ill
Based on the foregoing, we affirm the district court’s determination that a seizure occurred, and we remand this case to the district court for further proceedings consistent with this opinion. On remand, the district court should first determine whether Henry has met his burden of establishing that the seizure in this case was unreasonable (i.e., that Purnell’s mistake in using the Glock rather than the Taser was unreasonable). If the district court finds that Henry has met this burden, then Purnell will have the opportunity to demonstrate his entitlement to qualified immunity. Apart from our determination that a seizure occurred, we express no opinion on the ultimate merits of the case.
AFFIRMED IN PART, VACATED IN PART, AND REMANDED
Notes
. Qualified immunity "is an affirmative defense that must be pleaded by a defendant official.”
Harlow,
. When resolving cases on the first
Saucier
question, courts sometimes state that the absence of a constitutional violation entitles the defendant to qualified immunity. At least one circuit court has specifically rejected this approach, noting that a defendant in that instance prevails not because of qualified immunity but, instead, because the plaintiff "did not prove an essential element of the § 1983 claim.”
Ambrose v. Young,
.
But see Bryant,
. Several circuit courts place the entire burden of proof in qualified immunity cases on the plaintiff.
See, e.g., Breen v. Texas A & M Univ.,
. At oral argument, Henry's counsel agreed that no more than 3-5 seconds elapsed between the time Purnell drew the Glock and fired it, and that the entire flight and chase lasted no more than 10 seconds.
. Although not included in the district court's order, the record establishes that before Henry fled, Purnell informed him that he was under arrest and grabbed his arm while attempting to handcuff him.
See
J.A. 150-57. Notwithstanding this fact, the parties and the district court considered the seizure to have occurred, if at all, only when Purnell shot Henry. On this limited review, we will do likewise, and we will not consider the unexplored question of whether Purnell seized Henry by grabbing his arm.
See, e.g., Sibron
v.
New York,
. Finding that no seizure occurred, the court of appeals in
Brower
had analogized the case to a hypothetical situation in which a driver loses control of a vehicle and crashes while fleeing from police.
. Although we have not considered a case involving facts similar to those now before us, we have found Fourth Amendment seizures to have occurred in other factual situations where officers have made mistakes.
See, e.g., Miller v. Prince George's County,
. Because the "standards for analyzing claims of excessive force are the same under Articles 24 and 26 of the Maryland Constitution as that under the Fourth Amendment,”
Hines v. French,
. Purnell does not argue that an intentional use of the Glock would have been reasonable; likewise, Henry does not argue that Purnell’s decision to use the Taser was unreasonable. Thus, to the extent that it may be relevant in the qualified immunity analysis, the parties appear to agree that Purnell understood the constitutional restraints on his use of force in this circumstance.
. We note that in
Scott,
the Court stated that at the summary judgment stage, once a court has determined the relevant set of facts and drawn all inferences in favor of the nonmov-ing party to the extent supportable by the record, the reasonableness of an officer's actions "is a pure question of law.”
