What is the test for a motion to suppress evidence obtained from a search and seizure?

The Fourth Amendment of the federal Constitution requires state and federal courts to exclude evidence obtained from unreasonable government searches and seizures. (People v. Williams (1999) 20 Cal.4th 119, 125.) Section 1538.5 allows a defendant to move to suppress evidence obtained in an improper seizure. ( 1538.5.)

"The standard of appellate review of a trial court's ruling on a motion to suppress is well established. We defer to the trial court's factual findings, express or implied, where supported by substantial evidence. In determining whether, on the facts so found, the search or seizure was reasonable under the Fourth Amendment, we exercise our independent judgment. [Citations.]" (People v. Glaser (1995) 11 Cal.4th 354, 362.)