Reliance on the objective reasonableness of an official’s conduct, as measured by reference to clearly established law, should avoid excessive disruption of government and permit the resolution of many insubstantial claims on summary judgment. On summary judgment, the judge appropriately may determine, not only the currently applicable law, but whether that law was clearly established at the time an action occurred. If the law at that time was not clearly established, an official could not reasonably be expected to anticipate subsequent legal developments, nor could he fairly be said to “know” that the law forbade conduct not previously identified as unlawful. Until this threshold immunity question is resolved, discovery should not be allowed. If the law was clearly established, the immunity defense ordinarily should fail, since a reasonably competent public official should know the law governing his conduct. Nevertheless, if the official pleading the defense claims extraordinary circumstances and can prove that he neither knew nor should have known of the relevant legal standard, the defense should be sustained. But again, the defense would turn primarily on objective factors.
Id. at 818-19, 102 S.Ct. at 2738 (footnotes omitted).
In this case, plaintiff claims that his Fourth Amendment right to be secure in his home from unreasonable searches and seizures has been violated. As the Supreme Court has recently stated “[i]t is axiomatic that ‘the physical entry of the home is the chief evil against which the wording of the Fourth Amendment is directed.’ ” Welsh v. Wisconsin, 466 U.S. 740, 104 S.Ct. 2091, 2097, 80 L.Ed.2d 732 (1984), quoting United States v. United States District Court, 407 U.S. 297, 313, 92 S.Ct. 2125, 2134, 32 L.Ed.2d 752 (1972). It has long been settled that nighttime entries are particularly intrusive, Jones v. United States, 357 U.S. 493, 498, 78 S.Ct. 1253, 1256, 2 L.Ed.2d 1514 (1958), and that warrantless searches are per se unreasonable, subject only to a few “jealously and carefully drawn” exceptions. Coolidge v. New Hampshire, 403 U.S. 443, 454-55, 91 S.Ct. 2022, 2032, 29 L.Ed.2d 564 (1971).
Not surprisingly, defendants rely on one of these exceptions, consent, to justify their actions. They argue that Mr. Kittrell, a co-owner of the property, properly authorized their entry for purposes of serving the subpoena. In United States v. Matlock, 415 U.S. 164, 94 S.Ct. 988, 39 L.Ed.2d 242 (1974), the Court held that consent can be obtained from a third party with “common authority” over the property. Id. at 171, 94 S.Ct. at 993. However, a “mere property interest” is insufficient. Rather, common authority rests on the
mutual use of the property by persons generally having joint access or control for most purposes, so that it is reasonable to recognize that any of the co-inhabitants has the right to permit the inspection in his own right and that the others have assumed the risk that one of their number might permit the common area to be searched.
Id. at 171 n. 7, 94 S.Ct. at 993 n. 7. Therefore, although the standards for consent are “clearly established,” the difficulty arises because the legal conclusion that a proper consent was given is necessarily dependent on an analysis of the particular facts in each case. Thus, while Harlow speaks in terms of neat categories of questions of law and questions of fact, the issue of consent does not easily fit into either category.
The district court’s solution to this difficult problem was to hold a factual hearing on the issue of qualified immunity. In keeping with Harlow’s admonition that questions of qualified immunity should be resolved before trial and without extensive discovery, the district court proposed to hear testimony from all the witnesses to enable it to determine whether Mr. Kittrell had actual authority to consent to the entry, whether the agents’ belief that he had such authority was reasonable, and what the reasons were for serving the subpoena at the time and place they did. While we