The Fourth Amendment to the Constitution protects the public from unreasonable searches and seizures. It requires federal, state, and local law enforcement to obtain a search warrant based on probable cause or sworn testimony before conducting searches, and this includes searches of your car.

However, there are situations where police do not need a warrant to search your car.

The Motor Vehicle Exception

The protections provided by the Fourth Amendment are based on everyone having a right to privacy. But people waive their right to privacy when they allow the public to freely view their property. The Supreme Court ruled in Carrol v. United States that individuals in motor vehicles do not have the same expectation of privacy as those in buildings.

This means that items the police can clearly see when they pull a car over aren’t necessarily protected by the Fourth Amendment. Items that are not in plain sight are protected, but police officers may still search vehicles without a warrant in certain situations. So, the search warrant requirement does not always apply to every vehicle search.

In establishing the “motor vehicle exception,” the Supreme Court concluded that people do not typically live in their cars or use them to store personal possessions. However, the court further ruled that the motor vehicle exception should also apply to motor homes that are capable of being moved.

Probable Cause Is Still Required

Though the motor vehicle exception does exist for police, car searches without a warrant still require officers to have probable cause. The police need to show that there is probable cause that the vehicle contains:

• Evidence or proceeds (such as stolen money) of a crime
• Items used to commit a crime (such as drug paraphernalia)

Similarly, no warrant is required if police officers have probable cause to believe that the vehicle contains contraband, such as when they smell marijuana smoke emanating from the vehicle. However, case law is changing in some states that have legalized marijuana about whether simply the odor is enough to conduct a search.

Additionally, if you are arrested, such as for drunk driving, then police likely do not need a warrant to search your car. In addition to motor homes, court decisions have extended the scope of the motor vehicle exception to include trucks, trailers pulled by trucks, boats, houseboats, and airplanes.

When Police Must Obtain a Search Warrant

Under the Fourth Amendment, law enforcement must obtain search warrants in the following circumstances:

• When they do not have permission to conduct a search
• When the motor vehicle exception does not apply
• When items are not in plain sight
• When no emergency circumstances for a search exist

Before a judge or magistrate issues a search warrant, police must provide direct evidence that establishes probable cause for a search. This evidence could include the testimony of police officers, information provided by witnesses or informants, and physical evidence.

Terry Stops

Courts have generally supported police in situations when the safety of officers or members of the public may be in jeopardy. The U.S. Supreme Court ruled that police can search criminal suspects and their vehicles for weapons based upon reasonable suspicion rather than probable cause. A reasonable suspicion should be more than a hunch or a guess but less than probable cause. The Terry stop is named after the case which decided the issue.

Can Police Search an Impounded Vehicle?

While police cannot stop and impound a vehicle simply to conduct a search, they can legally search impounded vehicles. This can include a situation as seemingly minor as having your car towed for illegal parking. Law enforcement can also search stolen vehicles that have been recovered.

A Criminal Defense Attorney Can Protect Your Rights

You have constitutional protections against an illegal search of your car. If you believe your vehicle was unlawfully searched, a good criminal defense attorney may be able to get any evidence obtained from that search excluded. That could mean having your charges dismissed or reduced.