BOGGS, C.J., delivered the opinion of the court, in which KRUPANSKY, J., joined. CLAY, J. (pp. 777-86), delivered a separate dissenting opinion.
OPINION
Joseph Gaddis, a mentally ill man proceeding by his next friend, appeals from the district court’s grant of summary judgment to the defendants in his 42 U.S.C. § 1983 action. Mr. Gaddis claims that the individual defendants, members of two *766Michigan municipal police departments, violated his Fourth Amendment rights by stopping his car without justification, and by using excessive force in an ensuing confrontation that culminated in two officers shooting Gaddis. The district court concluded that Gaddis had failed as a matter of law to show that the defendants violated his constitutional rights. For the following reasons, we affirm.
I
Summary judgment is proper when there is no genuine issue of material fact and the moving party is entitled to judgment as a matter of law. Fed.R.Civ.P. 56(c). In our de novo review of the district court’s grant of summary judgment, we must resolve disputes of fact in favor of the nonmoving party, Gaddis, drawing all reasonable inferences in his favor. Burchett v. Kiefer, 310 F.3d 937, 941-42, 945 (6th Cir.2002). The application of this standard is complicated here by the fact that Gaddis, the only witness to the events at issue apart from the defendant officers and their colleagues, has been stipulated incompetent to testify due to mental illness. As discussed below, the record on appeal includes a videotape that captured many of the events at issue. We have carefully examined this tape along with the witnesses’ testimony in reviewing the district court’s judgment.
II
Gaddis’s encounter with the police began shortly before 4:00 a.m. on April 12, 1999, in Redford Township, Michigan. Defendant Matthew Bain, a Redford Township officer, spotted Gaddis’s car while patrolling alone on Telegraph Road. (The mounted video camera on Officer Bain’s patrol car yielded the tape that is the chief visual record of the encounter. However, because the car’s audio recording system was not working, the tape is silent.) Bain saw Gaddis weaving within the right lane: his car edged to the left to touch the divider line twice in a few hundred feet. Bain testified that Gaddis was also driving somewhat slowly, and the tape tends to confirm this, as it shows other cars passing Gaddis to the left on the sparsely trafficked road.
Bain also testified that he saw Gaddis slumping to the right inside his car as he held the wheel. The videotape neither reinforces nor throws doubt on this testimony. The interior of the car is dark on the tape and Gaddis’s posture cannot be made out, but the resolution of the video image is not high, and the camera’s point of view is slightly different from the vehicle driver’s. Bain pulled up alongside Gaddis’s car and confirmed to his satisfaction that Gaddis was leaning to the right, toward the passenger’s seat. Bain testified that he suspected Gaddis was driving while intoxicated, a crime in Michigan. See Mich. Comp. L. § 257.625.
Bain pulled behind Gaddis’s car and turned on his flashers and siren. When Gaddis failed to stop, Bain also employed his air horn. Gaddis kept driving until he reached a red light. Bain then left his patrol car and approached Gaddis’s stopped auto on foot. When the light changed to green, Gaddis turned right and drove away. Bain ran back to his car and pursued Gaddis again, and finally succeeded in pulling him over after about a block.
Bain left his car again and walked over to Gaddis’s car. The officer had his sidearm drawn when he stepped out of the car, but holstered it as he walked up to Gad-dis’s driver side window. Bain asked Gad-dis for his license and registration, to which Gaddis replied that his license was suspended (which turned out not to be true), and handed Bain an expired Michigan driver’s license. By this time a number of other uniformed police officers had arrived on the scene, including Dearborn *767Heights Officers John Burdick and Richard Duffany, who had been eating at a nearby restaurant and decided to assist Bain after hearing him drive by in pursuit of Gaddis.
Bain told Gaddis to get out of the car. Gaddis opened the door and stepped out with his hands inside his pockets. Bain testified that he ordered Gaddis to remove his hands from his pockets. The tape shows that shortly after Gaddis emerged, Bain grabbed him by the collar and pulled him slightly away from the car. Gaddis then removed his hands from his pockets, prompting a dramatic reaction: Bain jumped back, visibly alarmed, and he and the other officers drew their sidearms, pointing them at Gaddis. Officers Bain and Burdick later testified that Gaddis had a knife in his hand, while Duffany saw something shiny but wasn’t sure what it was. (The videotape image does not permit the viewer to verify directly whether Gaddis was holding a knife, a point we will discuss further in Part IV of this opinion.) At about this time a fourth officer arrived on the scene, Officer Champoux of the Redford Township department. Cham-poux pointed a shotgun at Gaddis, but testified that he could not tell if Gaddis had anything in his hand.
There ensued a standoff of two to three minutes’ duration. The officers testified that they told Gaddis repeatedly to drop his knife, and that Gaddis said something incoherent to Bain along the lines of: “Why are you doing this to me, Chris, like you did to me in California?” None of the officers was named Chris or had ever encountered Gaddis in California. Bain later testified that the “Chris” remark suggested to him that Gaddis was not acting rationally. Officer Burdick testified that he did not hear the remark. On the tape, Gaddis can be seen apparently speaking to the officers during the standoff. He gestures with his hands, but keeps them fairly low at his side.
Gaddis then stated that he wanted to leave.1 Bain stepped forward and sprayed Gaddis in the face with pepper spray. Meanwhile, Officer Burdick had been walking around to the passenger side of Gaddis’s car. Seconds after Bain used the pepper spray, Burdick clambered over the trunk of Gaddis’s car and tried to grab Gaddis. Gaddis reacted violently: he wheeled and struck at Burdick with his right, then his left hand. Gaddis’s right-handed strike was a windmilling motion arguably suggestive of an attempt to stab with a knife. Bain and Duffany testified that they saw Gaddis stab at Officer Bur-dick with a knife. They both began shooting, firing a total of 16 shots at Gaddis in a single burst. Burdick first heard the shots as he was falling backward over the back of Gaddis’s car. Gaddis was struck in the torso, right arm, buttocks, and left thigh, and fell to the ground. Champoux did not fire.
Evidence technicians recovered a knife from the street near Gaddis’s car, but did not fingerprint it.
Gaddis was charged with assault with intent to murder and with fleeing and eluding police. On June 8, 1999, he was found guilty in a bench trial of felonious assault (a lesser included offense), and not guilty on the fleeing count. Pursuant to a post-trial motion, however, Gaddis was later adjudged not guilty of the felonious assault charge as well.
Gaddis filed suit under 42 U.S.C. § 1983 against Officers Bain, Burdick, and Duffa-ney, alleging that they illegally detained him and used excessive force against him in violation of the Fourth Amendment. *768(He also asserted a claim of discrimination on the basis of his race and his mental illness, which he has abandoned on appeal.) He also sued the municipalities of Redford Township and Dearborn Heights, claiming that they maintained unlawful policies that caused the incident.
Plaintiff introduced the affidavit of James Fyfe, Ph.D., a former police officer and a professor of criminal justice. Prof. Fyfe opined that the officers unreasonably deviated from proper police techniques for dealing with emotionally disturbed persons (“EDPs”). In particular, he testified that officers using correct police techniques would recognize that “techniques of intimidation and force” are not likely to work on EDPs in the way they may work on rational persons. He testified that the police should instead have picked a single officer to talk calmly to the EDP, and should have refrained from unnecessary displays of force. Fyfe criticized Bain’s use of pepper spray, and described Burdick’s attempt to tackle Gaddis by surprise from behind as a “terrible tactic.”
The defendants moved for summary judgment, and the district court granted summary judgment on all claims on February 20, 2002. While the individual defendants had all raised the defense of qualified immunity, the district court did not reach the qualified immunity issue, but held that the defendants were entitled to summary judgment on the merits. Gaddis v. Redford Township, 188 F.Supp.2d 762 (E.D.Mich.2002).
As to Gaddis’s claim that the initial stop of his car was unlawful, the court held that reasonable suspicion was all that was required to justify an investigative stop of a car. Id. at 768. It further held that Gad-dis’s weaving in the lane and leaning over the seat provided reasonable suspicion. Indeed, it stated that the weaving, “simpli-citer,” would be enough to establish reasonable suspicion. Id. at 768-69.
As to the excessive force claim, the district court held that there was no genuine issue of material fact as to whether the officers’ use of force was reasonable. Id. at 772. It reasoned that the threat posed by Gaddis was quite high, as he had stabbed Officer Burdick. Id. at 770. The court also concluded that the officers’ “overall handling of the incident” did not violate the Fourth Amendment. Id. at 770-72. It noted that the “officers fired only one volley at Plaintiff, and ... did so immediately after Plaintiff had stabbed a policeman.” Id. at 771. The “unconstest-ed evidence” showed that “when the police shot Plaintiff, he had just stabbed Defendant Burdick, still appeared to be holding a knife, and was in close proximity to Defendant Burdick.” Id. at 772. The court also rejected Gaddis’s equal protection claims. Ibid.
Gaddis timely appealed to this court, appealing only the grant of summary judgment on his Fourth Amendment claims.
Ill
The first issue is whether the initial stop of Gaddis’s car violated the Fourth Amendment.
A
At the outset, we must determine the legal standard that governs a brief stop of a car for suspected drunk driving in a jurisdiction where, as in Michigan, such conduct is a criminal offense. See Mich. Comp. L. § 257.625(9)(a) (defining driving while intoxicated as a misdemeanor punishable by imprisonment). Unfortunately, this proves to be a complicated question, because different published opinions of this court have given inconsistent answers at different times.
By contrast, the Supreme Court has not wavered in this area. It has con*769sistently articulated a clear governing rule: when officers have reasonable suspicion that occupants of a vehicle are engaged in criminal activity, they may briefly stop the vehicle to investigate. E.g., United States v. Arvizu, 534 U.S. 266, 273, 122 S.Ct. 744, 151 L.Ed.2d 740 (2002); Alabama v. White, 496 U.S. 325, 328-32, 110 S.Ct. 2412, 110 L.Ed.2d 301 (1990); United States v. Hensley, 469 U.S. 221, 226, 105 S.Ct. 675, 83 L.Ed.2d 604 (1985).
This court’s earlier case law was consistent with this teaching. In United States v. Roberts, 986 F.2d 1026 (6th Cir.1993), we held that police may perform an investigatory stop of a vehicle when they have reasonable suspicion that the occupant is committing the crime of drunk driving. Id. at 1029-30.
However, two later cases potentially departed from this standard. Both arose in Tennessee, where, as in Michigan, driving while intoxicated is a crime. In United States v. Palomino, 100 F.3d 446 (6th Cir.1996), the court upheld the stop of a vehicle where police had grounds to suspect both drunk driving2 and the traffic violation of failure to stay within lanes.3 Id. at 448-49. Palomino argued that the stop was pretextual. He claimed that police had really stopped his car because he was Mexican and fit certain characteristics of a drug courier profile. Id. at 448. The court held that even if true, this was irrelevant, because the police “ha[d] probable cause to believe that a traffic violation had occurred,” justifying the stop. Ibid. This reasoning, while otherwise unexceptionable, could be read to lump criminal drunk driving together with failure to stay in lanes as a “traffic violation.” Ibid.
Palomino cited as authority the Supreme Court’s then-recent decision in Whren v. United States, 517 U.S. 806, 116 S.Ct. 1769, 135 L.Ed.2d 89 (1996). See 100 F.3d at 448. The cautiously worded opinion in Whren was consistent with the result in Palomino, but it did not support a general requirement of probable cause for stops based on suspicion of any offense, criminal or otherwise, involving a vehicle. Whren simply held that, when a defendant argued that his vehicle was stopped for improper reasons on the pretext of violating a traffic regulation, the officer’s improper motivations would not render the stop a violation of the Fourth Amendment if “the police ha[d] probable cause to believe that a traffic violation had occurred.” 517 U.S. at 810, 116 S.Ct. 1769. Whren did not involve a criminal offense. Rather, the defendants were stopped for speeding and failing to signal a right turn, in violation of municipal regulations. Ibid4
Our published decisions following Palomino contained no suggestion that Palomino had abrogated the bedrock rule permitting an investigatory vehicle stop when there is reasonable suspicion of a crime. See Houston v. Clark County Sheriff Deputy John Does 1-5, 174 F.3d 809, 813 (6th *770Cir.1999) (“Police may briefly stop an individual for investigation if they have a reasonable suspicion that the individual has committed a crime.... The same Fourth Amendment test applies to vehicle stops.”) (punctuation omitted) (citing, inter alia, Palomino, 100 F.3d at 449).5
However, four years after Palomino, a panel of this court decided United States v. Freeman, 209 F.3d 464 (6th Cir.2000), which held that Tennessee police were not justified in stopping the defendants’ mobile home after watching the vehicle veer out of its lane on a windy day. 209 F.3d at 465-66. The court held that this behavior was insufficient to justify a stop, whether it was viewed as evidence of failure to stay in lanes, or as evidence of drunk driving, which was a crime, though the court’s opinion did not discuss the violation/crime distinction. Ibid. At one point, the court specifically stated that the police were not justified in stopping Freeman for drunk driving because his weaving path “did not give [the officers] ... probable cause to stop the motor home.” 209 F.3d at 467 (emphasis added). Gaddis argues that Freeman is now the law of the circuit, and requires probable cause to stop a car for suspicion of criminal drunk driving. Freeman appears to conflict with our earlier decision in Roberts, as well as our many decisions, such as Houston, which affirm the bedrock rule that reasonable suspicion of a crime justifies a brief stop.
We have a settled procedure for resolving cases of intra-circuit conflict. “[A] panel of this [c]ourt cannot overrule the decision of another panel. The prior decision remains controlling authority unless an inconsistent decision of the United States Supreme Court requires modification of the decision or this Court sitting en banc overrules the prior decision.” Darrah v. City of Oak Park, 255 F.3d 301, 309 (6th Cir.2001).
Roberts squarely held that a stop for criminal drunk driving requires only reasonable suspicion. As the earliest decision on point, it must control, unless the intervening Supreme Court decision in Whren “require[d] modification” of its holding by a later panel. We do not read Palomino as so holding. At most, Palomino held that probable cause was sufficient to justify a stop for drunk driving, not that probable cause was necessary for such a stop. See 100 F.3d at 448-49. Nor did Freeman purport to modify past precedent in light of Whren; indeed, Freeman did not even cite Whren or Palomino. See 209 F.3d at 466-67.
Thus, at a minimum, applying the Dar-rah rule to our precedents yields grave doubt about the current authority of Freeman. Any lingering questions are resolved by the Supreme Court’s intervening decision in Arvizu, which explicitly reaffirmed the traditional rule that police may make “brief investigatory stops of ... vehicles ... if the officer’s action is supported by reasonable suspicion to believe that criminal activity may be afoot.” 534 U.S. at 273, 122 S.Ct. 744 (punctuation omitted); accord Weaver v. Shadoan, 340 F.3d 398, 407 (6th Cir.2003).
We therefore hold that a standard of reasonable suspicion governs the stop of Gaddis’s vehicle for suspicion of driving while intoxicated. This conclusion is also consistent with extensive authority from other circuits. E.g., United States v. Sanchez-Pena, 336 F.3d 431, 436 & n. 2 (5th Cir.2003); United States v. Colin, 314 F.3d 439, 442, 444 (9th Cir.2002); United States *771v. Wheat, 278 F.3d 722, 727-29 (8th Cir.2001); see also United States v. Chanthasouxat, 342 F.3d 1271, 1275 (11th Cir.2003) (“a [vehicle] stop is a constitutional detention if it is justified by reasonable suspicion under Terry or probable cause to believe a traffic violation has occurred”).6
B
Measured by the standard of reasonable suspicion, the stop was constitutional. Reasonable suspicion to stop a vehicle depends on a contextual inquiry that considers, in the well-known phrase, “the totality of the circumstances — the whole picture.” United States v. Cortez, 449 U.S. 411, 417, 101 S.Ct. 690, 66 L.Ed.2d 621 (1981). Here, Gaddis weaved twice to the left to touch the dividing line in a fairly short span. Bain’s testimony that Gaddis was leaning over to the right inside his car must also be accepted for summary judgment purposes, because it was uncontradicted by other testimony and the videotape does not tend to contradict it.7
These facts establish reasonable suspicion of drunk driving. Indeed, the Tenth Circuit held an investigatory stop for drunk driving justified on comparable facts in United States v. Ozbirn, 189 F.3d 1194 (10th Cir.1999), where an officer saw the defendant’s motor home “drift onto the shoulder twice within a quarter mile without any adverse circumstances like road or weather conditions to excuse ... the deviation.” Id. at 1199. Gaddis argues that our analysis should be controlled by Freeman, discussed above, and United States v. Gregory, 79 F.3d 973 (10th Cir.1996), which held that officers did not obtain a reasonable suspicion of drunk driving when they witnessed the defendant’s truck veer once in to the right emergency lane of the interstate. Id. at 975-76, 978-79. However, both cases are readily distinguished. In both Freeman and Gregory, the suspect vehicle swerved only once, and there were no other significant facts to suggest drunk driving.
*772Thus, summary judgment for all defendants was proper as to the legality of the initial vehicle stop.
IV
The more difficult issue in this case is the legality of the various officers’ uses of force in their confrontation with Gaddis. The sole constitutional standard for evaluating excessive force claims is the Fourth Amendment’s criterion of reasonableness. Graham v. Connor, 490 U.S. 386, 395, 109 S.Ct. 1865, 104 L.Ed.2d 443 (1989). Courts must apply an objective standard, looking to “the facts and circumstances of each particular case, including [1] the severity of the crime at issue, [2] whether the suspect pose[d] an immediate threat to the safety of the officers or others, and [3] whether he was actively resisting arrest or attempting to evade arrest by flight.” Russo v. City of Cincinnati, 953 F.2d 1036, 1044 (6th Cir.1992) (quoting Graham, 490 U.S. at 396, 109 S.Ct. 1865) (brackets added). At the same time, they must bear in mind that the Fourth Amendment “prohibits unreasonable seizures, not unreasonable or ill-advised conduct in general.” Dickerson v. McClellan, 101 F.3d 1151, 1162 (6th Cir.1996) (quoting Cole v. Bone, 993 F.2d 1328, 1333 (8th Cir.1993)).
In this circuit, courts faced with an excessive force case that involves several uses of force must generally “analyze the ... claims separately.” Ibid. They should “identiffy] the seizure and procee[d] to examine whether the force used to effect that seizure was reasonable in the totality of the circumstances, not whether it was reasonable for the police to create those circumstances.” Id. at 1161 (quotation marks omitted) (emphasis added). However, they may consider “the moments preceding [a] shooting” as part of the context of that shooting. Id. at 1162.
Here, Gaddis challenges four different events as constituting unreasonable force: Bain’s initial shoving or handling of Gaddis as Gaddis emerged from his car; Bain’s spraying of Gaddis as he stood in his car doorway; Burdick’s almost simultaneous grappling of Gaddis; and the ultimate volley of 16 shots fired at Gaddis after he struck at Burdick. We consider these uses of force in turn.
A
The district court did not examine Officer Bain’s brief initial grab of Gaddis as the latter emerged from his car. However, we hold that this act was not unconstitutionally excessive force. Bain was dealing with a suspect who had previously refused to stop for police, suggesting that he might be disoriented or intent on avoiding arrest. Bain testified that he grabbed Gaddis because he wanted to keep him from fleeing and to perform a pat-down search on Gaddis, who had his hands in his pockets. The record cannot be construed to cast doubt on this claim. The Supreme Court has instructed that “the right to make an arrest or investigatory stop carries with it the right to use some degree of physical coercion or threat thereof to effect it.” Graham, 490 U.S. at 396, 109 S.Ct. 1865. “Not every push or shove, even if it may later seem unnecessary in the peace of a judge’s chambers ... violates the Fourth Amendment.” Ibid. We acknowledge that even minor uses of force are unconstitutionally excessive if they are “totally gratuitous.” McDowell v. Rogers, 863 F.2d 1302, 1307 (6th Cir.1988). Here, however, Bain’s reasonable need to prevent Gaddis from fleeing and to discern whether he was armed justified his action.
B
Before we consider the officers’ later actions, we must decide whether the district court rightly held that there was no material dispute of fact on the critical *773question of whether Gaddis drew a knife from his pocket. If a reasonable jury could find that Gaddis did not have a knife, then it could unquestionably go on to find that shooting him was unconstitutionally excessive force, see Tennessee v. Garner, 471 U.S. 1, 11, 105 S.Ct. 1694, 85 L.Ed.2d 1 (1985) (holding that “[a] police officer may not seize an unarmed, nondangerous suspect by shooting him dead”), and the grant of summary judgment would have to be reversed. The presence or absence of a knife also affects our analysis of the officers’ uses of nonlethal force Bain’s decision to mace Gaddis and Burdick’s attempt to grapple Gaddis from behind. We review de novo the district court’s holding that no factual dispute existed. Burchett v. Kiefer, 310 F.3d 937, 941-42 (6th Cir.2002).
Since Gaddis could not testify, the only relevant evidence is the videotape and the testimony of the four officers. Bain and Burdick both testified that they saw a knife in Gaddis’s hand; Officer Duffany testified that he saw something shiny in Gaddis’s hand; and Officer Champoux, who was further from the scene, could not tell whether or not Gaddis had a knife. Bain saw a fairly small knife in Gaddis’s hand; Burdick described it as a “large” knife. Only Bain’s and Burdick’s testimony could be said to conflict. This sort of minor conflict of perception is common, and is not sufficient by itself to create a material dispute of fact as to the officers’ credibility.8
Gaddis argues, however, that the inability to see a knife on the videotape does create such a material dispute of fact. Because this argument has some force, we will explain our reasons for rejecting it in some detail. The videotape image is of low quality. It readily discloses the movements and postures of Gaddis and the officers, but not the details of their appearances. Gaddis’s hand is a vague blur. While the tape would not enable a juror to verify the presence of a knife by direct observation of Gaddis’s hand, it equally would not permit the juror to conclude that there was no knife there. (If it did, summary judgment would obviously be inappropriate.) Instead, the viewer’s sole clue is the body language of the actors during the encounter. And in this respect, the officers’ reactions powerfully corroborate their testimony that Gaddis produced a knife. On the tape, when Gaddis removes his hands from his pockets, Bain jumps back in obvious alarm. He pulls out his service pistol and covers Gaddis with it, and the other officers follow suit. The reaction is inexplicable unless something threatening was in Gaddis’s hands. In addition, Gaddis later uses a windmilling motion to strike at Burdick, which is suggestive of a knife stab. Thus the tape as a whole tends to reinforce the officers’ testimony that there was a knife, not to contradict it.
All admissible evidence in the case points to the conclusion that the knife was present. At most, the poor quality of the tape might be said to raise a “scintilla of evidence” in support of Gaddis’s position, but that is not enough to withstand sum*774mary judgment. Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 252, 106 S.Ct. 2505, 91 L.Ed.2d 202 (1986). We conclude that there was no material dispute as to whether Gaddis had a knife.
C
We turn next to Bain’s decision to use pepper spray to try to incapacitate Gaddis. As noted before, after Gaddis drew his knife, there followed a standoff of about two minutes, during which Gaddis stood in the doorway of his car and the officers repeatedly ordered him to drop his weapon. During this time Gaddis made an incoherent remark to Bain, calling him “Chris” and referring to a nonexistent pri- or confrontation with him in California. Gaddis then announced that he wanted to leave. It was at this point that Bain stepped forward and sprayed him. Gaddis argues that on the facts of this encounter, the use of pepper spray was unconstitutionally excessive.
One of the main purposes of nonlethal, temporarily incapacitating devices such as pepper spray is to give police effective options short of lethal force that can be used to take custody of an armed suspect who refuses to be lawfully arrested or detained. As a general matter, this court has expressed doubt “that the use of nonlethal force against an armed and volatile suspect constitutes excessive force.” Ewolski v. City of Brunswick, 287 F.3d 492, 508 (6th Cir.2002).9 Gaddis’s case falls in or near this category: he was armed with a knife and his conduct was at least somewhat “volatile,” as he was refusing to submit to arrest. Moreover, we have also held that in sufficiently pressing circumstances, officers may use pepper spray to take custody of unarmed suspects. In Monday v. Oullette, 118 F.3d 1099 (6th Cir.1997), we upheld judgment as a matter of law for police officers who used spray to subdue an unarmed individual they feared would injure himself or commit suicide by overdosing on pills if not taken into custody. Id. at 1104-05. Of course, there must exist an objective justification for the use of pepper spray. In Adams v. Metiva, 31 F.3d 375 (6th Cir.1994), we held that police who repeatedly sprayed mace in the face of an unarmed plaintiff who was not resisting and was not subject to lawful arrest would be liable for excessive force as a matter of law. Id. at 384-87.
Measured by this case law and the three factors outlined by the Supreme Court in Graham, we cannot say that Officer Bain’s decision to use pepper spray could be found to be objectively unreasonable. The amount of force Bain used, though not trivial, was moderate. At the time he acted, the officers had probable cause to suspect Gaddis of two crimes that were also moderate in severity: driving while intoxicated, a misdemeanor for first offenders under Michigan law, and fleeing an officer.10 While Gaddis arguably did not pose an immediate threat to the officers’ safety as he stood next to his car brandishing a knife (since the officers were able to keep their distance), Bain could have reasonably concluded from Gaddis’s erratic driving and behavior that he would pose a danger to other motorists if allowed to flee. Gaddis had announced his desire *775to leave the scene, and this statement prompted Bain to spray him. That fact is also relevant to the final Graham factor, namely whether the suspect was resisting arrest. Gaddis’s remarks indicated an intent to continue evading arrest, and his brandishing of a knife was reasonably interpreted as a sign of intent to resist, perhaps violently.
In sum, Bain used an intermediate degree of nonlethal force to subdue a suspect who had previously attempted to evade arrest, was brandishing a knife, showed signs of intoxication or other impairment, and posed a clear risk of leaving the scene behind the wheel of a car. It cannot be said that this action was unconstitutionally excessive.
Gaddis disputes this reasoning, arguing that his incoherent remark about “Chris” put Bain on notice that Gaddis was disturbed, and that this made special tactics appropriate. Gaddis argues that a reasonable officer, suspecting Gaddis’s disability, would not have responded to the brandishing of a knife by pointing a gun at Gaddis. Nor would he have “provoked” Gaddis by using an irritating and disorienting device such as pepper spray against him, as Bain did. Instead, a reasonable officer would have used a nonconfrontational manner that would ensure that Gaddis was not provoked to violence. To support this argument, Gaddis offered the affidavit of Prof. James Fyfe, a law enforcement expert. Fyfe testified that in his opinion, the officers’ tactics in the encounter with Gad-dis were “terrible” and were not in keeping with optimal police procedures for dealing with mentally or emotionally disturbed persons.
We acknowledge that a suspect’s apparent mental state is one of the “facts and circumstances of [the] particular case,” Graham, 490 U.S. at 396, 109 S.Ct. 1865, that should be considered in weighing an excessive force claim. Moreover, the opinions of properly qualified experts such as Mr. Fyfe are often entitled “to be given ... weight” in this determination. Russo, 953 F.2d at 1047.11 In Russo, we drew partially upon such testimony in concluding that the inadequate training procedures of the Cincinnati police department may have contributed to the shooting death of the plaintiffs suicidal, mentally ill decedent. See id. at 1046-47,
However, Gaddis’s arguments here are weakened by the fact that Bain had only fragmentary evidence that Gaddis was mentally disturbed. This distinguishes the case from Russo, where officers knew from the outset that the suspect was mentally disturbed because the initial call to the police came from the mental institution the suspect had left. Id. at 1039. Here, Gad-dis’s incoherent conduct was arguably as consistent with Bain’s initial hypothesis that Gaddis was driving while intoxicated as it was with mental disturbance. The Supreme Court has instructed that we are to judge officers’ conduct from the “perspective of a reasonable officer on the scene, rather than with the 20/20 vision of hindsight.” Graham, 490 U.S. at 396, 109 S.Ct. 1865. There may be more than one reasonable response to a given situation, and when this is so, the Fourth Amendment does not require officers to use “the most prudent course of action” to handle it. See Cole, 993 F.2d at 1334. In light of the circumstances and our reasoning above, we conclude Fyfe’s affidavit is not sufficient to create a material issue of fact *776as to the reasonableness of Bain’s use of pepper spray.
D
Similar reasoning leads us to conclude that Officer Burdick’s decision to grapple with Gaddis in order to subdue him was not unconstitutionally excessive force. Burdick did not strike Gaddis or employ any weapons; his actions involved a degree of force comparable to Bain’s use of pepper spray. Moreover, Gaddis’s argument that a different response was required because of his emotional disturbance does not apply to Burdick. It was uncontroverted that Burdick did not hear the “Chris” remark that most strongly tended to suggest Gaddis’s incoherence or emotional disturbance. As we have noted, the reasonableness of his response must be gauged in terms of the information available to him, not with hindsight. And “reasonableness” does not require that an action be “prudent” or the “best suited” to the situation, only that it not be unconstitutionally disproportionate in degree to the circumstances. Given that Bain’s use of nonlethal force against Gaddis was reasonable, as we held at pp. 773-76 supra, it follows that Burdick’s decision to grapple with Gaddis was reasonable as well.
E
Gaddis reacted to Burdick’s attempt to grapple with him by stabbing at Burdick with his knife. Our last issue for consideration is the constitutionality of Officers Bain and Duffany’s decision to respond to this attack with lethal force, by shooting Gaddis several times.
Lethal force is justified in order to protect a fellow officer or a civilian from a threat of serious physical harm. Brandenburg v. Cureton, 882 F.2d 211, 215 (6th Cir.1989). An attack with a knife certainly meets this criterion.12 See Pirsein v. Village of Berrien Springs, No. 92-1258, 1992 WL 348944 (6th Cir. Nov.24, 1992) (unpublished opinion). Bain and Duffany saw Gaddis strike at Burdick with a knife in his right hand. It was reasonable for them to respond with lethal force.
Gaddis relies upon Samples v. City of Atlanta, cited supra, and Zuchel v. City of Denver, 997 F.2d 730 (10th Cir.1993), to argue that his use of a knife did not necessarily render the officers’ actions justified. In Samples, the Eleventh Circuit denied qualified immunity to an officer who fatally shot Samples as Samples approached him with a three-inch folding knife. 846 F.2d at 1331-33. Zuchel involved a suspect who was believed to have a knife, and who was fatally shot by an officer shortly after he turned to face the officer. 997 F.2d at 735-36. The Tenth Circuit held that these facts were sufficient to support a verdict for the plaintiff against the officer’s municipal employer. Ibid.
Both cases are distinguishable from Gaddis’s. In Samples, the officer shot a suspect who was, at most, merely opening a knife, and had not yet attacked anyone with it. 846 F.2d at 1332. Moreover, Samples was shot once in the back — a detail that was highly salient to his case, because there was only one officer confronting Samples. The back wound suggested that the officer might have used lethal force against Samples at a time when he clearly did not pose a threat to the officer. Ibid. Here, Gaddis had not only extended the blade of his knife but had attacked Officer Burdick with it. Moreover, while Gaddis, like Samples, also *777received a wound from the back from the shots fired at him, the fact was that multiple officers were firing at Gaddis from different vantage points after his attempt to stab Burdick. Thus Gaddis’s back wound does not tend to undercut the officers’ testimony (corroborated by the videotape) that they fired only in response to the knife attack.
In Zuchel, the facts suggested that Zu-chel was not threatening anyone or brandishing a weapon aggressively when police shot him. Indeed, the only evidence that Zuchel even had a knife came from one bystander’s shouted warning to the police. 997 F.2d at 735-36. Here, again, Gaddis had a knife and used it.
Gaddis finally suggests that even if his actions justified a lethal response, the officers crossed the constitutional line by firing sixteen shots at him. We disagree. While the two officers fired a total of sixteen shots at him, it was a single volley. That distinguishes Gaddis’s case from precedents such as Russo, where police went on to fire a second and third volley at the suspect even though there was a factual dispute as to whether he still posed a serious threat. See 953 F.2d at 1045. Bain’s and Duffany’s decisions to use their weapons to respond to Gaddis’s attack were individually justifiable, and the fact that there were two of them responding simultaneously, thereby producing a larger volley, does not change the reasonableness of their conduct.
V
For the foregoing reasons, the district court’s grant of summary judgment to the officers is AFFIRMED. Because there was no underlying constitutional violation by the officers, the municipal defendants cannot be held liable to Gaddis. Monday, 118 F.3d at 1105. The grant of summary judgment to the municipal defendants is therefore also AFFIRMED.