What is the test for admitting evidence secured by unlawful search and seizure?

In the instant proceeding, as pointed out by respondent, 'The error which the petitioner here seeks to raise is clearly no more than a claimed error in the admission of evidence. He asserts that the judgment was obtained through the admission of evidence secured by unlawful and unreasonable search and seizure, in violation of the Fourth Amendment [135 Cal.App.2d 289] to the United States Constitution and Article I, Section 19 of the California Constitution, and it is therefore void. In support of this contention he cites the recent case of People v. Cahan, 44 [Cal.2d 434, 282 P.2d 905] which overruled prior decisions in California and held that evidence secured by unconstitutional search and seizure was inadmissible.'

As stated in the case of People v. Cahan, supra, 44 Cal.2d at page 434, 282 P.2d 905, relied upon by appellant, the rule announced therein excluding evidence secured by unconstitutional search and seizure is a 'judicially declared rule of evidence', and no more.