At a probable cause determination, the legality of the arrest for an attempt at applying the exclusionary rule isn’t appropriately litigated. That comes after the charges land in Superior Court. Barajas v. Appellate Div. of the Superior Court, 2019 Cal. App. LEXIS 975 (2d Dist. Oct. 4, 2019):
Barajas has framed the question here as one of constitutional import. It is not. There is a Fourth Amendment right to be free of unreasonable search and seizure. There is no corresponding constitutional entitlement to the exclusion of evidence. The exclusionary rule was created judicially at the federal level and later codified in California. And while it is obviously necessary that a defendant be able to litigate suppression of evidence obtained in violation of the Fourth Amendment, it is not constitutionally or otherwise required (or even possible) for that to be done at a section 991 [probable cause] hearing. That the timing and notice requirements of section 1538.5 may be inconvenient for in-custody misdemeanor defendants does not deprive those defendants of the benefit of the exclusionary rule, the purpose of which, incidentally, is not to benefit defendants at all, but rather to deter law enforcement from Fourth Amendment violations in the first instance. That purpose and the achievement of that end is in no way related or subject to the timing of a section 991 hearing.
Section 991 is indisputably analogous to section 995 in many respects. One respect in which it is not, however, is that section 1538.5—the California codification of the exclusionary rule—names section 995 and invests the same exclusionary power in a section 995 motion that it does in a section 1538.5 motion.
Section 991 defines the People’s burden on a misdemeanor probable cause determination as establishing “probable cause to believe that a public offense has been committed and that the defendant is guilty thereof.” (§ 991, subd. (a).) Gerstein and Walters said that language means that the “People need only establish a prima facie case of probable cause to detain on sworn statements or testimony ‘”sufficient to warrant a prudent man in believing that the [suspect] had committed or was committing an offense.”‘” (Walters, supra, 15 Cal.3d at p. 753, quoting Gerstein, supra, 420 U.S. at p. 111.)
The probable cause determination contemplated by section 991 does not include a determination that evidence was unlawfully obtained; the sole and exclusive means for a misdemeanor defendant to secure that determination is a noticed motion under section 1538.5. The only question for a trial court to answer on a defendant’s section 991 motion is whether facts that have not yet been excluded by operation of a noticed motion under section 1538.5 exist “sufficient to warrant a prudent man in believing” that “a public offense has been committed and that the defendant is guilty thereof.” (Gerstein, supra, 420 U.S. at p. 111; § 991, subd. (a).)