California Search and Seizure Laws

Last Updated on July 10, 2025

For you to be charged with a crime, police must find enough evidence to indicate your guilt. For the charges to result in a conviction, the evidence must be strong enough to prove your guilt beyond a reasonable doubt. While the California and US Constitutions protect citizens from illegal and unreasonable search and seizure, police often violate those rights to collect enough evidence against the defendant. Always work with a skilled criminal attorney like Peter Liss if you believe you were the victim of a warrantless or otherwise illegal search in San Diego.

What is an “Unreasonable Search and Seizure?”

The Fourth Amendment of the US Constitution reads:

“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.”

Article 1, Section 13 of the California state constitution reads nearly identically, though a few minor words are switched here and there. While the old-fashioned legalese of these documents might be hard to decipher for most modern English speakers, essentially, both constitutions state that people have the right to be free of unreasonable searches and seizures of their houses, papers, and other property. They also state that warrants permitting investigators to perform a search can only be issued with probable cause and must include specific details regarding what will be searched and what can be seized as evidence.

While the idea behind the text can be explained easily enough, defining the limits of what is or is not reasonable and what constitutes sufficient probable cause is a complicated subject that legal scholars, attorneys, and judges regularly debate. Many arguments about whether or not federal or state search and seizure laws have been violated in a given situation eventually end up being settled in the US and California Supreme Courts.

Exceptions to California Search Warrant Laws

While search and seizure laws often seem simple, many exceptions to warrant requirements can make these laws somewhat complex. An officer cannot search your home without a warrant unless:

• you consent to a search
• illegal items are sitting in plain view
• the officer has reasonable suspicion that there is an immediate threat to either someone in your home or evidence related to the case (what are known as “exigent circumstances”)

If the police come to someone’s house and hear someone screaming “help,” for example, they can enter without a warrant. Even if no one was in danger, anything they found in the home at that point could be used as evidence. However, a criminal lawyer could fight the use of this evidence in court by claiming no reasonable person would really believe it was an emergency.

To successfully keep evidence out of a case where an officer claimed to be acting due to an exigent emergency, the defendant’s lawyer must show that the suspect’s Fourth Amendment rights were violated. To do this, the attorney would need to show the police officer wrongly bypassed the standard warrant requirement by acting without probable cause, and that an average person would recognize that no one was actually in danger.

The plain sight doctrine states that police can perform a search if they see evidence of a crime in plain view. So, for example, if you let police into your home to answer questions and they can see inside a room that is clearly filled with illegal guns and drugs, they can then enter the room and seize the evidence. They could even do this if you refused to let them in your home, but they could see the contraband through a window in front of your home.

When do Police Need a Warrant to Search a Vehicle?

Police don’t always need to get a warrant to perform a search. In most cases, police can search your vehicle with no more than probable cause. Probable cause is defined as a situation where circumstances would lead a reasonable person to believe there is evidence of a crime.

For example, suppose you have been pulled over and show signs of intoxication from cocaine, such as talking too fast, sniffing frequently, and having dilated pupils. In that case, an officer may use that as grounds for probable cause to search your car for cocaine. On the other hand, a broken tail light alone isn’t considered probable cause for your vehicle to be searched. What constitutes probable cause in a given situation is up for debate. Your lawyer may be able to argue that what an officer claims was probable cause was anything but.

If your vehicle is in your home’s driveway, garage, or carport, a warrant is necessary before a search can be performed because these areas are considered an extension of your home. The same exceptions to warrant laws apply to vehicles parked in a home’s driveway, meaning that if the police can see evidence of a crime in the windows of a car parked on your property, they do not need a warrant. Similarly, if exigent circumstances indicate someone is in danger or that evidence is being destroyed in your vehicle, officers can perform a warrantless search.

When a vehicle is impounded, police can search it without restriction.

Can Police Search Motorhomes Without a Warrant?

Fans of Breaking Bad are probably familiar with Walter White’s claim that a motor home cannot be searched without a warrant as long as it is used as a private domicile. But while Walter was a great chemist, he was no lawyer. The Supreme Court made the exact opposite ruling on the subject in a 1985 case, arguing that because RVs can be moved so easily, requiring police to obtain a warrant was impractical.

That being said, there is a legal grey area regarding fifth-wheel or double-wide trailers that cannot be easily moved. For California residents living in trailer parks where moving the trailer is difficult, if not impossible, to do in a time, search warrants are usually still required under the law.

Can Police Search a Cell Phone Without a Warrant?

No, in the Supreme Court ruling in Riley Vs. California, the court ruled unanimously that warrantless cell phone searches violate the Fourth Amendment. Beyond that, once police obtain a search warrant for a cell phone, courts have ruled that police cannot force individuals to unlock phones protected with passcodes or biometric data, as it violates a defendant’s right to be free from self-incrimination.

Police in California can search your cell phone if:

• they have a valid warrant
• you consent to a search
• there are extenuating circumstances, such as a bomb threat
• you are on probation or parole —police can even forcefully use biometric data to unlock a phone owned by someone on probation or parole

Police face many limitations when it comes to searching the phones of suspects. However, they can often get around these limits and avoid getting a warrant by contacting a third party you have already given access to, such as an app, website, or cell phone company. The Supreme Court has ruled that police cannot obtain cell phone location data from third parties but can still obtain call logs, emails, texts, DMs, photos, and more.

Do Not Consent to a Search

Never talk to the police without a legal representative present. It’s easy to say something that can later incriminate you. Even worse, police often sidestep warrants by getting people to give up their rights voluntarily.

If you let the police into your home to talk, you may not necessarily agree to let them search your house. But by allowing them into your living room, anything in plain sight can be used as evidence without a warrant. Police allowed to enter a home often push to use the restroom or get a glass of water so they can enter other rooms and casually look for evidence lurking in plain sight from these areas. If the police ask if they can look around while in your home, even saying something like “yeah, whatever,” can be considered permission to search your home, even if you just thought they wanted to look in your living room.

You Cannot Revoke Consent for a Search

Once you grant an officer permission to search your property, you cannot revoke that consent later and require them to obtain a warrant in most cases. Again, it is always best to have an attorney present when dealing with the police to ensure your rights are protected, even if you feel you have nothing to hide.

Do Police Need a Warrant to Get a DNA Sample?

While police need a search warrant to obtain a DNA sample from you directly, they often bypass this process and instead just get a cup, cigarette, or other items with your DNA on it that you disposed of and then test it. Nowadays, they can even indirectly test your DNA through familial DNA sites.

What Happens When Police Perform an Illegal Search?

When evidence is illegally collected due to a violation of the suspect’s Fourth Amendment rights, it doesn’t matter if the case is a misdemeanor or felony; illegally collected evidence cannot be legally used. Unfortunately, many California residents who are victims of illegal search and seizure do not realize the police violated their rights and, therefore, they do not end up challenging this evidence.

While it’s always best to have an attorney present during a search, if the police search you without a lawyer present, write down as many details as possible about the encounter as soon as possible. Provide this information to your lawyer so he can evaluate if you have been victimized by an illegal search.

If your rights were violated, any evidence uncovered during the search cannot be used against you. Evidence related to the search but not found directly at the scene is still considered inadmissible. For example, suppose police search your home illegally and see photos showing you have a secret compartment in your desk drawer at work. In that case, they cannot use any evidence they discover in the desk drawer because the original search that tipped them off to this evidence was illegal.

In cases involving severe rights violations or where there is insufficient evidence, once illegally collected evidence is declared inadmissible, the charges against you may even be dropped.

Because these laws can be so complex and because police often take advantage of a suspect’s ignorance of the law, anyone who has been accused of a crime should always work with a criminal defense attorney. Your lawyer can help challenge any evidence that may have violated your rights by going against California’s search and seizure laws. If you have been accused of a crime, please call (760) 643-4050 to schedule a free initial consultation with Peter M. Liss.