The Fourth Amendment prohibits police from extending the time reasonably necessary to complete a routine traffic stop in order to have a drug dog sniff a car when police lack reasonable suspicion of drug activity, the U.S. Supreme Court held April 2l in Rodriguez v. United States. The Court previously held in Illinois v. Caballes, 543 U.S. 405 (2005), that a dog sniff conducted during a lawful traffic stop was not an unreasonable seizure. Rodriguez limits the time and circumstances when dog sniffs can occur. 
          Facts:  A police officer stopped Dennys Rodriguez for swerving onto a highway shoulder in violation of state law.  The officer had a drug dog in his patrol car. The officer checked Rodriguez’s license, registration and insurance, and checked the license of a passenger.  Rodriguez said he swerved to avoid a pothole. The officer called for a second officer to come to the scene.  Meanwhile, he wrote a warning ticket, gave it to Rodriguez, and returned all documents he had taken. The officer then asked for permission to walk his dog around the car.  Rodriguez refused.  The officer then ordered Rodriguez out of the car to wait for the second officer.  Rodriguez complied. The second officer arrived about seven or eight minutes later.  They led the dog around the car.  The dog alerted to drugs.
Rodriguez was charged with a drug offense.  He filed a motion to suppress, contending that the officer had unreasonably prolonged the traffic stop without reasonable suspicion. At the suppression hearing, the officer testified that he “got all the reason[s] for the stop out of the way” once he issued the warning ticket.  But he testified that he did not consider Rodriguez “free to leave” because he wanted to have the dog sniff the car. The District Court denied the motion to suppress on grounds that the traffic stop was extended by only seven or eight minutes, which was only a de minimus intrusion on Rodriguez’s Fourth Amendment rights and, thus, allowed.  The Eighth Circuit affirmed.
          Holding:  The Supreme Court held that police may not extend an otherwise-completed traffic stop, absent reasonable suspicion, in order to conduct a dog sniff. Absent reasonable suspicion of other criminal activity, a traffic stop may last no longer than reasonably necessary to carry out the purpose of the stop.  “Authority for the seizure … ends when the tasks tied to the traffic infraction are – or reasonably should have been – completed.”
          The Court further stated that an officer can conduct “certain unrelated checks” during a traffic stop, “but he may not do so in a way that prolongs the stop, absent the reasonable suspicion ordinarily demanded to justify detaining an individual.” Routine inquires that can be conducted during a traffic stop include checking a driver’s license, registration, insurance, and whether there are outstanding warrants.  A dog sniff is different than these routine inquires because it is aimed at detecting evidence of ordinary criminal activity. “The critical question … is not whether the dog sniff occurs before or after the officer issues a ticket,” the Court held, “but whether conducting the sniff ‘prolongs’ – i.e., adds time to – ‘the stop.’”
          The Court remanded the case to determine whether the officer had reasonable suspicion of criminal activity to justify detaining Rodriguez beyond the time necessary to complete the traffic stop.