What is the effect of the exclusionary rule on evidence obtained from a search and seizure?

If this first part of the test shows a violation of the Fourth Amendment, that is, an objectively unreasonable search or seizure, prosecutorial use at trial of the evidence obtained from the search or seizure is "usually preclude[d]." (Illinois v. Krull, supra, 480 U.S. at p. 347, 107 S.Ct. at p. 1165-66 [94 L.Ed.2d at p. 373].) However, the second part of the test, to determine whether exclusion of the evidence would advance the remedial purpose of the exclusionary rule, is undertaken only if the search or seizure fails the first part of the test.