Eight Minutes Too Many: Supreme Court Decides that Traffic Stop Prolonged for Use of a Drug Detection Dog Violated the Fourth Amendment


By: Brian R. Dempsey

During a lawful traffic stop, a police officer can ask a driver to exit a vehicle, conduct a free-air drug sniff with a trained canine, and even investigate the possibility of criminal conduct which is unrelated to the original purpose of the traffic stop.  The Supreme Court has held that these are “de minimis” intrusions on personal liberty that do not require reasonable suspicion of criminal activity in order to comport with the Fourth Amendment.

In Rodriguez v. United States, the Supreme Court was asked to decide whether the same rule applies after the tasks relating to the traffic stop have been completed.

The case arose from a midnight traffic stop which was conducted by an officer who was accompanied by a trained drug-sniffing dog.  After the officer issued a warning to the driver (and thereby completed the traffic stop), he called another officer to come to the scene to provide security while he had his canine conduct a free-air sniff around the car.  The traffic stop was prolonged for seven or eight minutes until the dog alerted on the car.  The officers then discovered a bag of methamphetamine, leading to a federal prosecution which ultimately led to this appeal from the denial of the driver’s motion to suppress the incriminating evidence.

In a 6-3 decision which was handed down earlier this week, the Court concluded that an officer’s authority to detain a driver for a traffic stop “ends when tasks tied to the traffic infraction are — or reasonably should have been – completed.” Justice Ruth Bader Ginsburg wrote for the majority, and was joined by Chief Justice John Roberts and Justices Antonin Scalia, Stephen Breyer, Sonia Sotomayor, and Elena Kagan.

Justices Samuel Alito, Clarence Thomas, and Anthony Kennedy dissented.  In his dissent, Alito concluded that independent suspicion existed for the continued investigation – an issue which the majority left open for the lower courts to decide.  Alito also found it “perverse” that if the officer had not waited for a back-up officer for safety reasons, he could have performed a solo dog sniff without any constitutional problem.  For his part, Justice Thomas criticized the majority’s rule because it appears to be linked to the efficiency of the individual officer conducting the stop.  After all, the Court’s prior Fourth Amendment jurisprudence had consistently emphasized that the Fourth Amendment reasonableness inquiry does not hinge on the characteristics of the individual officer conducting the seizure.

In sum, the Court concluded that law enforcement activities unrelated to the traffic stop, while not illegal in and of themselves, are permitted only if they do not measurably extend the duration of the stop.  In the wake of this opinion, it is likely that future cases involving roadside investigations will turn on fact-intensive determinations regarding whether officers have completed traffic stops with reasonable efficiency, or whether they have dragged their feet to accommodate unrelated investigative tasks.

The full opinion can be found at the Court’s website: