Does the exclusionary rule apply to suppress evidence?

The exclusionary rule is remedial, and its application to suppress evidence is not warranted in every case where the Fourth Amendment has been violated. "[T]he exclusionary rule 'operates as a judicially created remedy designed to safeguard against future violations of Fourth Amendment rights through the rule's general deterrent effect. [Citations.]' [Citation.] Thus, its ''"prime purpose"' is to '"effectuate"' the Fourth Amendment's guarantee against unreasonable searches or seizures by 'deter[ring] future unlawful police conduct.' [Citation.] Moreover, because the exclusionary rule is a 'remedial device,' its application is 'restricted to those situations in which its remedial purpose is effectively advanced.' [Citation.] Thus, application of the exclusionary rule '"is unwarranted"' where it would '"not result in appreciable deterrence."'" (People v. Willis (2002) 28 Cal.4th 22, 30.) More specifically, "exclusion is proper '"only if it can be said that the law enforcement officer had knowledge, or may properly be charged with knowledge, that the search was unconstitutional. . . ."'" (Id. at p. 31, italics added.)

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