What is the test for obtaining a search warrant from a police officer in a protected area such as a curtilage?

"In reviewing the trial court's ruling on the suppression motion, we uphold any factual finding, express or implied, that is supported by substantial evidence, but we independently assess, as a matter of law, whether the challenged search or seizure conforms to constitutional standards of reasonableness." (People v. Hughes (2002) 27 Cal.4th 287, 327, 116 Cal.Rptr.2d 401, 39 P.3d 432.)

When the prosecution relies on evidence obtained by law enforcement officers from a protected area such as a curtilage without a warrant, it bears "the burden of establishing either that no search occurred, or that the search undertaken by the officers was justified by some exception to the warrant requirement" such as exigent circumstances. (People v. Camacho supra, 23 Cal.4th at p. 830, 98 Cal.Rptr.2d 232, 3 P.3d 878.)