For many years, the Supreme Court has permitted police to search the passenger compartment of a vehicle any time an occupant of the car is arrested. These so-called “searches incident to arrest” were authorized in New York v. Belton (1981) based in large part on concerns about officer safety, namely that the suspect might dive for a weapon hidden in the car. As a result, police have grown accustomed to searching vehicles for “safety reasons” even after the suspect has been taken into custody. This doesn’t protect officers, but it certainly encourages police to make more arrests so they can do more searches.

Well, that’s finally going to change. The Supreme Court ruled today in Arizona v. Gant that vehicle searches following an arrest are legal only if the suspect has access to the vehicle or if officers reasonably believe the vehicle contains evidence related to that arrest. In other words, police are now required to have an actual reason to justify the vehicle search, instead of being allowed to do it automatically. This decision restores some much needed logic and common sense to the way many warrantless vehicle searches are analyzed under the 4th Amendment.

We’ve long been concerned about the ability of police to use arrests for minor crimes as a way of overriding a citizen’s refusal of consent. Since many states (and Supreme court precedent) allow officers to perform a full arrest for certain traffic offenses, we’ve often worried that police could sometimes strong-arm their way into a vehicle by arresting the driver for a traffic violation instead of just writing a ticket. Today’s ruling in Gant, however, creates an obstacle to these types of “pretext arrests,” because traffic violations are observed infractions for which relevant evidence will not be contained in the vehicle. In that sense, the ruling will likely result in some extra protection for citizens who exercise 4th Amendment rights during a traffic stop.

Beyond the basic legal issues at hand, the case has additional symbolic significance because it truly affects every officer on the street. Every cop is trained to search vehicles automatically after making an arrest, and now every officer will have to learn a new, more nuanced, policy on car searches that is designed to protect individual rights. With today’s ruling, the Supreme Court sends an important message to law enforcement that the 4th Amendment still means something in America.