Although some of us may take the U.S. Constitution for granted, many of our daily rights in America are based on the Constitution and its amendments. The First and Second Amendments are often cited in media and pop culture (the right to freedom of speech and the right to bear arms, respectively). 

 But many Americans don’t know about other amendments, including their Fourth Amendment rights. While they may not have the hot-button appeal of some other amendments, your Fourth Amendment rights are extremely important—especially during a traffic stop. 

What Are Your Fourth Amendment Rights?

Simply put, the Fourth Amendment protects Americans from unreasonable searches and seizures. The amendment states, in part, that “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.”  

 What this generally means as a practical matter is that the police (or any other government agency) can’t search you without having a legitimate reason to do so. This includes your person (body, clothing on your body) or property, such as your house, car, office, and anywhere else where you store your belongings. Likewise, unless something you own is illegal or you are reasonably suspected of being involved in a crime, a government employee or agent can’t take it from you.

 Whether a particular type of search is considered constitutionally reasonable is determined case-by-case, based on a combination of public and private interests. Each person’s Fourth Amendment rights have to be weighed against the state or federal government’s interests in investigating and prosecuting suspected crimes, for example. 

 In practice, in order to search you or your belongings, the police need to obtain a warrant from a judge granting permission in the name of public safety. However, there are times when the police may conduct a search without obtaining a warrant. The extent to which you’re protected by the Fourth Amendment depends, in part, on where you are or what you’re doing when a search is conducted. 

Are Police Allowed to Search Your Car at a Traffic Stop?

Traffic stops have been the subject of much Fourth Amendment-related scrutiny. On the surface, because of these Fourth Amendment rights, the police cannot pull you over or search your vehicle without a search warrant unless there is a constitutionally-recognized basis for the stop or search.  

Traffic Violations 

For starters, an officer may conduct a traffic stop if they have reasonable suspicion that a traffic violation has occurred. This means that if you are caught committing a traffic offense (like speeding), or even if there is reasonable suspicion that you have been doing so, you can be pulled over. This is not limited to traffic-related wrongdoings. Any suspicion of illegal activity grants permission for officers of the law to pull you over and potentially search your car. 

Suspicion of Criminal Activity

Once you’re pulled over, your car may also be subject to search if an officer has a new reason to suspect a crime. Anytime a police officer determines that there is probable cause to believe that a vehicle contains evidence of criminal activity, they may lawfully search any area in which the evidence might be found.

 While this does grant a fair amount of leeway, it’s important to note that the officers are only allowed to search the specific areas of your vehicle where they might reasonably expect to find evidence. All other parts of your vehicle are still protected under the Fourth Amendment. 

 Getting pulled over for a legitimate traffic violation does give the police some discretion to conduct other searches. For example, for safety purposes, an officer may conduct a pat-down of the driver and passengers during a lawful traffic stop, even without direct suspicion of other illegal activity.

Checkpoints and Random Stops

There are times when, in the interest of public safety, police can set up checkpoints that stop cars without specific suspicion about any individual driver. For one, a state may use highway sobriety checkpoints in an effort to combat drunk driving. This only applies to intoxicated driving, however. That means that a state may not create a highway checkpoint program whose primary purpose is the discovery of illegal narcotics. This only applies to the creation of the checkpoint, however. If the checkpoint already exists, walking a narcotic sniffing dog around the outside of a car subject to a valid traffic stop does not require reasonable, explainable suspicion.

 Another reason a state may have a valid reason to set up a random checkpoint is to conduct brief stops to ask drivers for information pertaining to the investigation of a recent crime that has occurred on that highway. Offering information when stopped is strictly voluntary, however, and drivers may decline to answer questions without fear of legal repercussions. 

Other Exceptions

A few exceptions to this law are worth noting. Special law enforcement concerns will sometimes justify highway stops without any individualized suspicion. While this may seem somewhat vague and subjective, the exact reach of these concerns is subject to review in court. 

 Another exception can be a pain for anyone driving across the border with Mexico or Canada. International border officers are allowed to conduct routine stops and searches for anyone crossing into the United States, with no other reason needed.

 Finally, bear in mind that these specific instances are all based on federal law. Your local state constitution may have additional restrictions that can impact traffic stops or search procedures in your area.

Other Fourth Amendment Rights

Precisely what property is protected under your Fourth Amendment rights has sparked some debate. One example of this is when you are storing your property in a place that doesn’t belong to you. This can include students’ lockers at school, which are the property of the school rather than the student. While students do have the same rights as any other citizens, a 1985 Supreme Court ruling determined that schools do not need to obtain a warrant to search students under their authority. The fundamental rule that the student does need to be under suspicion for specific wrongdoing still applies, however.

 Another area of debate has been in the world of information that’s gathered by our devices. A 2018 Supreme Court ruling determined that location data generated when cell phones connect to nearby cell towers are protected by your Fourth Amendment rights.