On a chilly morning in February 1989, members of the Portland Chapter of the AIDS Coalition to Unleash Power (“Act Up!/Portland”) gathered at the Federal Building in Portland to protest Food and Drug Administration (“FDA”) policies regarding the testing and approval of drugs designed to combat the AIDS virus. Ap-pellees, six men and four women who participated in the demonstration, were arrested, loaded in a van, and taken to the United States Courthouse. There, they were strip searched by United States Marshals.
Appellees filed a complaint against Appellants, the Marshals who ordered and conducted the search, alleging causes of action under Bivens v. Six Unknown Named Agents of the Federal Bureau of Narcotics, 403 U.S. 388, 91 S.Ct. 1999, 29 L.Ed.2d 619 (1971), for violations of their Fourth Amendment rights. Appellants moved for summary judgment on the Bivens action on the ground that they were protected from suit by qualified immunity under Harlow v. Fitzgerald, 457 U.S. 800, 102 S.Ct. 2727, 73 L.Ed.2d 396 (1982). After the district court denied their motion without comment, Appellants filed a motion for reconsideration. The court denied that motion as well, explaining that, at the time of the search, the law governing strip searches was clearly established. The court ruled that the question of whether, in light of that law, Appellants’ decision to conduct a strip search was reasonable was one for the jury.
Pursuant to the collateral order doctrine, we have jurisdiction over interlocutory appeals from orders denying summary judgment on the basis of qualified immunity. See Mitchell v. Forsyth, 472 U.S. 511, 530, 105 S.Ct. 2806, 2817, 86 L.Ed.2d 411 (1985); DiMartini v. Ferrin, 889 F.2d 922, 924 (9th Cir.1989), amended on other grounds, 906 F.2d 465 (9th Cir.1990), cert. denied, — U.S. -, 111 S.Ct. 2796, 115 L.Ed.2d 970 (1991).
I
FACTS
Because the district court regarded the question of “reasonable suspicion” as one for the jury, it did not review the facts in the record pertaining to that determination. It appears from the record before us, however, that those facts are essentially not in dispute. At 8:00 a.m. on the morning of *871February 27, 1989, the demonstration organized by Act Up!/Portland began outside the Federal Building in Portland. Although most of the demonstrators remained outside, Appellees entered the building, bringing the noisy protest to the hallway outside the FDA’s office. When they refused to leave, Appellees were arrested by Federal Protective Service officers for creating a public disturbance in violation of 41 C.F.R. § 101-20.305 (1989).1
Appellees were escorted down to a loading dock where they were restrained in flexible plastic handcuffs and loaded into Marshals Service vans that were waiting to deliver them to the federal courthouse. As one of the vans pulled away from the building, its driver noticed that the van was tilting to the side. He radioed the Marshals Service Headquarters that his tires were losing air and that he believed they had been slashed.
When the vans arrived at the courthouse, Appellees were taken to a holding facility where several other prisoners, some of whom may have been charged with violent offenses, were being held. Immediately upon their arrival, Deputy Oliverio, the Operations Supervisor, determined that Appel-lees should be strip searched. He based his decision on two factors. The first was his belief, based on the van driver’s report that his tires had been slashed and the fact that Appellees were wearing what Oliverio described as “bulky” winter clothing, that Appellees might be carrying concealed contraband. The second was his concern that if any of the Appellees were carrying dangerous contraband, one of the prisoners the facility was currently holding might obtain that contraband by reaching through the bars of his or her own cell into Appellees’ cells. Oliverio knew nothing about what had happened at the demonstration, or about the circumstances of Appellees’ arrest.
Initially, Appellees were separated by sex and placed in holding cells. The men were then brought one by one to another cell where they were strip searched by Appellants Kauffman and Morod and another deputy, within view of other male prisoners and marshals. The women were placed in a “transitory” cell, and after about an hour and forty-five minutes were taken one by one to a private interview room where they were searched by a female deputy before being placed in a “female” cell. Following the strip searches, Appellees were detained until they could be processed. They were cited and released by 12:50 p.m.
II
QUALIFIED IMMUNITY
We review a district court’s denial of a qualified immunity defense de novo. Baker v. Racansky, 887 F.2d 183, 185 (9th Cir.1989).
When a law enforcement officer asserts qualified immunity from liability for Fourth Amendment violations, the district court must determine whether, in light of clearly established principles governing the conduct in question, the officer objectively could have believed that his conduct was lawful. See Anderson v. Creighton, 483 U.S. 635, 641, 107 S.Ct. 3034, 3039, 97 L.Ed.2d 523 (1987). This standard requires a two-part analysis: 1) Was the law governing the official’s conduct clearly established? 2) Under that law, could a reasonable officer have believed the conduct was lawful?
At the time Appellants strip searched the Appellees, it was clearly established in this circuit that it is unlawful to strip search an arrestee brought to a jail facility on charges of committing a minor *872offense,2 unless the officer directing the search possesses “a reasonable suspicion that the individual arrestee is carrying or concealing contraband.” Giles v. Ackerman, 746 F.2d 614, 617 (9th Cir.1984), cert. denied, 471 U.S. 1053, 105 S.Ct. 2114, 85 L.Ed.2d 479 (1985). Reasonable suspicion may be based on “such factors as the nature of the offense, the arrestee’s appearance and conduct, and the prior arrest record.” Id. Adhering to the Supreme Court’s direction in Bell v. Wolfish, 441 U.S. 520, 559, 99 S.Ct. 1861, 1884, 60 L.Ed.2d 447 (1979), the Giles test accounts for the fact that local jail facilities frequently confront difficult security problems, and balances those facilities’ interests in controlling such problems against the privacy interests of arrestees. See 746 F.2d at 617.
The district court recognized that the legal principles governing Appellants’ conduct were firmly established at the time of the search. The district court failed to consider whether, in light of those principles, a reasonable officer in Appellants’ position could have believed his actions were lawful. See Anderson, 483 U.S. at 641, 107 S.Ct. at 3039; Hunter v. Bryant, — U.S. -, -, 112 S.Ct. 534, 537, 116 L.Ed.2d 589 (1991) (per curiam). That determination is preliminary to the determination whether Appellants’ decision to strip search was in fact based on reasonable suspicion, which the court properly recognized is “a question for the jury as to the merits of the claim.” Absent a genuine dispute of material fact, however, this issue may go to the jury only if the court has determined that the officer is not entitled to qualified immunity. If a reasonable officer could have believed that Appellants were justified under Giles in strip searching the Appellees, Appellants are entitled to qualified immunity. This is so notwithstanding that reasonable officers could disagree on this issue, Malley v. Briggs, 475 U.S. 335, 341, 106 S.Ct. 1092, 1096, 89 L.Ed.2d 271 (1986), because even officers who mistakenly conclude that reasonable suspicion is present are entitled to immunity so long as that conclusion is objectively reasonable, Anderson, 483 U.S. at 641, 107 S.Ct. at 3034.
Furthermore, although Appellees complained that the men were strip searched “in a semi-public area, observed by other deputy marshals and other individuals also in federal custody,” the court did not consider whether the search was conducted in a reasonable manner. At the time of the search it was clearly established that the Fourth Amendment requires that any strip search be conducted in a reasonable manner, and accordingly that officers must respect arrestees’ privacy interests. See Vaughan v. Ricketts, 859 F.2d 736, 741 (9th Cir.1988), cert. denied, 490 U.S. 1012, 109 S.Ct. 1655, 104 L.Ed.2d 169 (1989).
A line of cases decided by this Court holds that the question whether a reasonable officer could have believed probable cause existed goes to the jury unless there is only one conclusion a rational jury could reach. See, e.g., Bryant v. U.S. Treasury Dep’t, 903 F.2d 717, 721 (9th Cir.1990); Kennedy v. Los Angeles Police Dep’t, 901 F.2d 702, 706 (9th Cir.1989). The Supreme Court rejected this approach in Hunter v. Bryant, — U.S. -, -, 112 S.Ct. 534, 537, 116 L.Ed.2d 589 (1991) (per curiam), rev’g Bryant, 903 F.2d at 717. The Court admonished that our approach ignored the fact that qualified immunity “ ‘is an immunity from suit rather than a mere defense to liability.’ ” Id. — U.S. at -, 112 S.Ct. at 536 (quoting Forsyth, 472 U.S. at 526, 105 S.Ct. at 2815). Immunity “ordinarily should be decided by the court long before trial.” Id. — U.S. at -, 112 S.Ct. at 537. The district court relied upon our decision in Kennedy and it did not have the benefit of the Supreme Court’s decision in Hunter, which was decided after the district court ruled.
*873We interpret Hunter to hold that the question of whether a reasonable officer could have believed probable cause (or reasonable suspicion) existed to justify a search or an arrest is “an essentially legal question,” Forsyth, 472 U.S. at 526, 105 S.Ct. at 2815, that should be determined by the district court at the earliest possible point in the litigation. Where the underlying facts are undisputed, a district court must determine the issue on motion for summary judgment.
The threshold determination of whether the law governing the conduct at issue is clearly established is a question of law for the court. Harlow, 457 U.S. at 818, 102 S.Ct. at 2738. The determination of whether the facts alleged could support a reasonable belief in the existence of probable cause or reasonable suspicion is also a question of law to be determined by the court. Hunter, — U.S. at -, 112 S.Ct. at 537; see Anderson, 483 U.S. at 641, 107 S.Ct. at 3039; Malley, 475 U.S. at 341, 106 S.Ct. at 1096; Forsyth, 472 U.S. at 526, 105 S.Ct. at 2815; Harlow, 457 U.S. at 813-20, 102 S.Ct. at 2735-39.
If a genuine issue of fact exists preventing a determination of qualified immunity at summary judgment, the case must proceed to trial. Where a Fourth Amendment violation is claimed, the factual issues that may preclude a determination of qualified immunity on summary judgment fall into two categories. First, a determination of reasonable suspicion or probable cause requires an inquiry as to the facts and circumstances within an officer’s knowledge. United States v. Maybusher, 735 F.2d 366, 371 (9th Cir.1984) (reasonable suspicion), cert. denied, 469 U.S. 1110, 105 S.Ct. 790, 83 L.Ed.2d 783 (1985); United States v. Greene, 783 F.2d 1364, 1367 (9th Cir.) (probable cause), cert. denied, 476 U.S. 1185, 106 S.Ct. 2923, 91 L.Ed.2d 551 (1986). These are matters of fact to be determined, where genuine disputes of a material nature exist, by the fact finder.3 Second, the determination of what conduct underlies the alleged violation— what the officer and claimant did or failed to do — is a determination of fact. We hold, however, that the determination whether those facts support an objective belief that probable cause or reasonable suspicion existed is ordinarily a question for the court. It is not in itself a factual issue that can preclude summary judgment.
Of course, if the facts alleged by the defendant officer could not support a reasonable belief that his conduct was lawful, he is not entitled to qualified immunity. If the facts are undisputed, summary judgment for the plaintiff on the merits may be appropriate. Cf. Morgan v. Woessner, 975 F.2d 629 (9th Cir.1992) (affirming JNOV for plaintiff where court determined that, even construing facts in defendant’s favor, defendant was not entitled to qualified immunity).
We hold, therefore, that the district court erred by denying Appellants’ motion for summary judgment without determining whether a reasonable officer in Appellants’ position could have believed, in light of clearly established legal principles, that his conduct was lawful. We REVERSE the court’s order denying Appellants’ motion for summary judgment, and REMAND the case to determine whether there exists a genuine issue of material fact underlying the qualified immunity question. If, as appears from the record before us, there is no such issue, then the court should determine whether a reasonable officer in Appellants’ position could have thought that the circumstances gave rise to individualized reasonable suspicion that Appellees were carrying contraband, and if so, whether a reasonable officer in Appellants’ position could have thought that the manner in which they were searched complied with Vaughan. If, and only if, it answers either of these questions in the negative, the case should go to the jury to determine whether the searches violated the Fourth Amendment or, if summary judgment on that issue is appropriate, damages. If the court finds that a genuine issue of underlying fact does exist, it should postpone the qualified immunity *874determination until the facts have been developed at trial.
REVERSED and REMANDED.
DISSENT FROM THE FAILURE OF THE COURT TO HEAR THIS CASE EN BANC.
. Section 101-20.305 provides:
Disturbances.
Any loitering, disorderly conduct, or other conduct on property which creates loud or unusual noise or a nuisance; .which unreasonably obstructs the usual use of entrances, foyers, lobbies, corridors, offices, elevators, stairways, or parking lots; which otherwise impedes or disrupts the performance of official duties by Government employees; or which prevents the general public from obtaining the administrative services provided on the property in a timely manner, is prohibited.
. At the time of this search, the maximum penalty for violating 41 C.F.R. § 101-20.305 was a fine of $50 or imprisonment of not more than 30 days or both. See 40 U.S.C. § 318c (1988); 41 C.F.R. § 101-20.315 (1989). Because the maximum penalties prescribed by these provisions are so small, we have described violations of 41 C.F.R. § 101-20.3 as "petty.” See United States v. Stansell, 847 F.2d 609, 611-612 (9th Cir.1988).
. This determination does not, however, entail an inquiry into the officer’s subjective intentions; merely his knowledge. Anderson, 483 U.S. at 641, 107 S.Ct. at 3039; see Harlow, 457 U.S. at 815-19, 102 S.Ct. at 2736-39.