Rodriguez v. United States

**Question presented** Does the Fourth Amendment (the part of the Constitution that protects against unreasonable searches and seizures) allow police to keep a driver detained after a routine traffic stop is finished, just so an officer can bring a drug‑sniffing dog to the car, when the officer has no separate reason (reasonable suspicion) to believe there are drugs? **Holding** The Supreme Court said **no**. If a police stop is based only on a traffic violation, the stop must end as soon as the officer has taken care of everything needed to address that violation. Extending the stop to run a dog sniff without any independent suspicion of drugs is an illegal seizure. **Why the Court reached that result (majority reasoning, in plain language)** 1. A routine traffic stop is like a brief “Terry stop” – a temporary detention that is allowed only to deal with the traffic problem that caused the stop. 2. The stop’s “mission” includes things such as checking the driver’s license, registration, insurance, and looking for any outstanding warrants – all things that promote road safety. 3. Once those traffic‑related tasks are completed (or should have been completed), the officer’s authority to detain the driver ends. 4. A dog sniff that is not part of those traffic‑related tasks does not fall within the officer’s mission. Adding a sniff after the warning ticket was written, and holding the driver for another 7‑8 minutes, went beyond what the Constitution permits. 5. The Court emphasized that the length of the detention, not just whether the sniff happens before or after the ticket, matters. Any extra time added for an unrelated investigation makes the stop unlawful unless the officer has separate, specific suspicion of a crime. **Dissent’s view (in plain language)** Justice Kennedy (joined by Justices Thomas and Alito) argued that the police officer had already completed the traffic‑related work and that a brief, minimally intrusive dog sniff does not substantially add to the detention. They believed the sniff should be allowed as long as it does not dramatically lengthen the stop. **Vote count** The decision was **6‑3**. The majority opinion was written by Justice Ginsburg and joined by Chief Justice Roberts and Justices Scalia, Breyer, Sotomayor, and Kagan. The dissent was written by Justice Kennedy, with Justices Thomas and Alito also dissenting.