In United States v. Leon, 468 U.S. 897 (1984) the United States Supreme Court addressed the question of "whether the Fourth Amendment exclusionary rule should be modified so as not to bar the use in the prosecution's case in chief of evidence obtained by officers acting in reasonable reliance on a search warrant issued by a detached and neutral magistrate but ultimately found to be unsupported by probable cause." 468 U.S. at 900. The search warrant issued in the Leon case was challenged by motions to suppress the evidence seized. After an evidentiary hearing, the district court found the affidavit insufficient to establish probable cause and suppressed some of the evidence as to some defendants but did not suppress all of the evidence as to all the defendants because none of the defendants had standing to challenge all the searches. The government had argued that the police officer acted in good faith and, thus, the Fourth Amendment exclusionary rule should not apply where evidence is seized with a reasonable, good faith reliance on a search warrant. The district court declined to accept that argument. On appeal, the Court of Appeals for the Ninth Circuit affirmed the district court, finding that the information in the affidavit that set forth facts to demonstrate the basis of the informant's knowledge of criminal activity, was fatally stale. The Court of Appeals also determined that the information provided by the informant was inadequate under both prongs of the two-part test of Aguilar v. Texas, 378 U.S. 108 (1964), and Spinelli v. United States, 393 U.S. 410 (1969). The Court of Appeals declined to recognize a good faith exception to the Fourth Amendment exclusionary rule. The United States Supreme Court, however, upon reviewing the case, opined that, in the Fourth Amendment context, the exclusionary rule could "be modified somewhat without jeopardizing its ability to perform its intended functions" and reversed the judgment of the Court of Appeals. 468 U.S. at 905. The specific holding of Leon was that, although the search warrant was ultimately found to be unsupported by probable cause, the evidence obtained would not be excluded if the officers reasonably relied on a search warrant issued by a detached and neutral judge. In Leon, the United States Supreme Court provides guidance for analyzing a suppression issue. Leon explains that "suppression of evidence obtained pursuant to a warrant should be ordered only on a case-by-case basis and only in those unusual cases in which exclusion will further the purposes of the exclusionary rule." Id. at 918. The United States Supreme Court observes in Leon that "deference to the magistrate ... is not boundless" and that "the courts must also insist that the magistrate purport to 'perform his "neutral and detached" function and not serve merely as a rubber stamp for the police. ... A magistrate failing to 'manifest that neutrality and detachment demanded of a judicial officer when presented with a warrant application' and who acts instead as 'an adjunct law enforcement officer' cannot provide valid authorization for an otherwise unconstitutional search." Leon, 468 U.S. at 914. The United States Supreme Court held that the Fourth Amendment exclusionary rule should not bar the use of evidence obtained by officers acting in reasonable reliance upon a search warrant issued by a detached and neutral magistrate that is later determined to be invalid. The Court stated: It is the magistrate's responsibility to determine whether the officer's allegations establish probable cause and, if so, to issue a warrant comporting in form with the requirements of the Fourth Amendment. In the ordinary case, an officer cannot be expected to question the magistrate's probable-cause determination or his judgment that the form of the warrant is technically sufficient. Once the warrant issues, there is literally nothing more the policeman can do in seeking to comply with the law. 468 U.S. at 921. In Leon, the Supreme Court stated that the good-faith exception does not apply in four instances, including the instance "where the officer's affidavit is so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable." Leon, 468 U.S. at 923. In United States v. Leon (1984) 468 U.S. 897, the Supreme Court held that when "an officer acting with objective good faith has obtained a search warrant from a judge or magistrate and acted within its scope," the "marginal or nonexistent benefits" produced by suppressing the evidence obtained "cannot justify the substantial costs of exclusion." (Leon, supra, 468 U.S. at pp. 920, 922.) "The exclusionary rule is designed to deter police misconduct rather than to punish the errors of judges and magistrates." (Id. at p. 916.) Therefore, suppression of evidence is an appropriate remedy only if "the magistrate or judge in issuing the warrant was misled by information in an affidavit that the affiant knew was false or would have known was false except for his reckless disregard of the truth," the affidavit is "'so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable,'" or the affidavit is so deficient in particularizing the place to be searched or the things to be seized that the executing officer "cannot reasonably presume it to be valid." (Leon, supra, at p. 923.) The Court stated that although "'a warrant issued by a magistrate normally suffices to establish' that a law enforcement officer has 'acted in good faith in conducting the search' ," the officer must objectively rely in good faith on the determination of probable cause. (Id. at p. 922.) If "a reasonably well trained officer" would have realized a search was illegal despite the warrant (id. at p. 922, fn. 23), the search cannot be upheld. There are generally four instances where the good faith exception would not apply: (1) if the magistrate who issued the warrant was misled by information in the affidavit known to be false by the declarant; (2) the magistrate "wholly abandoned his judicial role"; (3) the affidavit was "'so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable'"; or; (4) the warrant is facially deficient. (Id. at p. 923) The Supreme Court held that evidence may not be suppressed if the officer executing the warrant relies in good faith on a warrant issued by a detached and neutral magistrate that later is determined to be invalid. An officer will have no reasonable grounds for believing the warrant was properly issued where the magistrate was misled by information in an affidavit which the officer knew or should have known was false, where the magistrate wholly abandoned his judicial role, where the affidavit was so lacking in indicia of probable cause as to render belief in its existence entirely unreasonable, or when the warrant was so facially deficient that the officer could not reasonably presume it to be valid. (Id. at p. 923.)