What is the test for obtaining a warrant to search a person's home?

The Fourth Amendment to the United States Constitution, made applicable to the states by the Fourteenth Amendment (Mapp v. Ohio (1961) 367 U.S. 643, 81 S.Ct. 1684, 6 L.Ed.2d 1081), provides: "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."

"The Fourth Amendment protects the individual's privacy in a variety of settings. In none is the zone of privacy more clearly defined than when bounded by the unambiguous physical dimensions of an individual's home--a zone that finds its roots in clear and specific constitutional terms: 'The right of the people to be secure in their houses ... shall not be violated.' That language unequivocally establishes the proposition that '[a]t the very core [of the Fourth Amendment] stands the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion.' ... In terms that apply equally to seizures of property and to seizures of persons, the Fourth Amendment has drawn a firm line at the entrance to the house. Absent exigent circumstances, that threshold may not [45 Cal.App.4th 172] reasonably be crossed without a warrant." (Payton v. New York (1980) 445 U.S. 573, 589-590, 100 S.Ct. 1371, 1381-1382, 63 L.Ed.2d 639, citation omitted.)