The California Constitution and the 4th Amendment to the U.S. Constitution guarantee our right to be free of search and seizure by police without a warrant or probable cause. Illegally-seized evidence must be suppressed and excluded in the criminal prosecution against a defendant whose rights have been violated.
YOU HAVE THE RIGHT TO REFUSE (AMONG OTHERS):
to consent to any search of your person or property without a warrant.
to answer questions from police, or make any statements.
to open your door to your home unless there is an emergency or a search warrant.
to be detained or questioned anywhere, even at airports.
PROBABLE CAUSE: "Probable cause" must be proved or the seized evidence can't be used against you. Probable cause simply means that there must be a reasonable belief that a crime has been or is about to be committed or that there is contraband present.
THE SMELL OF MARIJUANA: The smell of marijuana (burnt or fresh) by police or their trained dogs is probable cause to search the suspect's person and car without a warrant, and may form the basis to obtain a search warrant for a home or other place.
REASONABLE EXPECTATION OF PRIVACY IS REQUIRED! In California, as well as in many other states and under Federal law, the defendant must have a reasonable expectation of privacy, called "standing," in the place that is subject to search in order to challenge illegally-seized evidence and have it suppressed.
CARS: People who have their possessions, such as backpacks, in someone else's car have no standing to challenge an illegal search.There is no recognized right of privacy in someone else's car unless you are the driver at the time of the search. However, all persons have reasonable expectation of privacy regarding the clothing they are wearing and anything on their person.
HOUSE GUESTS: Overnight guests have the same rights as the occupants to object to the illegal search of the host's home. Campsites and motel & hotel rooms are also protected.
BACKYARDS: Renters' and homeowners' enclosed yards (e.g. a yard with a 6-foot fence, even with small cracks) are protected from police peeping close up through the fence, but not from aerial observation.
IN JAIL: There is no expectation of privacy while in jail, including telephone calls and in visiting rooms, except with lawyers.
TELEPHONE CALLS on hard wire, cell phones, and in telephone booths are protected, unless one party agrees to police taps or listening in, but cordless phone conversations do not have expectation of privacy because they can be heard by neighbors with the same frequency.
PUBLIC SCHOOLOFFICIALS, teachers, principals, etc. may search a student's personal belongings at school without a warrant or probable cause [New Jersey v. T.L.0, (1985) 469 US. 325].
MAIL: Deliveries by private mail carriers (FedEx, LIPS, DHL) are not protected by the 4th Amendment. Private carriers can search packages and envelopes without a warrant or probable cause. Domestic U. S. Mail is protected by the 4th Amendment and cannot be searched without a warrant, except in an emergency.