Police normally need one of two things to search your home or vehicle: a warrant or your consent. Without either of those, the Fourth Amendment prohibits the police from conducting any searches of your property. However, police are able to conduct a search without a warrant if they have probable cause to believe that a crime is taking place or has taken place.
A warrantless search based on probable cause is most common during traffic stops. For example, if a police officer stops a driver and smells marijuana when the driver rolls down the window, the officer could search the vehicle or have the driver perform a field sobriety test, based on the chance that the driver has marijuana in the vehicle or used marijuana before getting behind the wheel. There is no set guideline for when an officer does and does not have probable cause to conduct a search, and instead it varies on a case-by-case basis. If the search is challenged in court, then the court will decide if there was enough probable cause to search the property.
Minor violations are not enough evidence to constitute probable cause. Here’s the difference between situations that would and would not show probable cause of a crime:
If there’s a house party going on and the police show up because of a noise complaint, they could ask the home owner to keep their music down, but they wouldn’t have probable cause to come in and search the house. However, if they spotted several people who appeared to be underage and intoxicated, then they would have probable cause to check IDs and search the premises, if those people were in fact underage.
If a police officer pulls a driver over for failing to signal before making a turn, that alone doesn’t give the officer probable cause to search the driver’s vehicle. The driver could have simply forgotten, had something in his hand at the time or he may be in a rental car that he’s not familiar with. But if the driver is slurring his words and has bloodshot eyes, that would give the officer probable cause to conduct a field sobriety test or a breathalyzer to check if the driver was intoxicated.
The standards for establishing probable cause are obviously much lower than the standards for establishing guilt with a defendant, so there can be situations where the police have probable cause to conduct a search, even though the person is in fact innocent of any crime.
While police do use probable cause to conduct searches, what occurs far more often is people giving up their constitutional rights by consenting to searches when police don’t have a warrant. Police will typically try to obtain your consent before using probable cause, because they know that as soon as they get your consent, the search is completely legal. That’s why it’s important to know your rights.
Police don’t need to explain to you that you have the right to refuse a search, and they often trick people into consenting to searches. An officer may casually ask you if they can “take a look around,” or ask you why you wouldn’t allow them to search your vehicle if you “have nothing to hide.” They may also make it seem like they could just get a warrant, and if they do they’re going to search more than if you just consent.
Don’t fall for any of these traps. You have the right to refuse a warrantless search. The simplest response is to say “I don’t consent to any police searches.” If they continue to try convincing you to consent, ask them if you’re being detained, or if you’re free to leave.
Refusing to consent to any police searches is the most effective way to protect yourself. A police officer may still conduct a search if they think they have probable cause, but if you’re prosecuted for a crime based on what they find, your lawyer could argue that it was an unconstitutional search. If you gave your consent, your lawyer won’t be able to argue that anymore.