Unconstitutional “Detours”

There is no more important context to have clear Fourth Amendment search and seizure limitations than the traffic stop. “Police pull over more than 50,000 drivers on a typical day,” resulting in seizures of “more than 20 million motorists every year.” The frequency of traffic stops is compounded by the malleability of their potential legal justifications. In Whren v. United States, the Supreme Court held that a pretextual traffic stop motivated by a desire to investigate a vehicle’s occupants for unrelated criminal activity (for which the officer does not yet have probable cause) does not violate the Fourth Amendment so long as the officer had probable cause to stop the vehicle for a traffic violation. Though Whren does not allow the officer to search the vehicle without additional probable cause, there are several lesser investigations—such as intrusive lines of questioning and even drug dog sniffs—that officers might perform to continue to develop unrelated suspicions.