Canine Olfactory Investigation Without Reasonable Suspicion Violates Fourth Amendment

Overview: Police may not extend a routine traffic stop to give a police dog time to conduct a search for narcotics, the United States Supreme Court held this week. The Court determined that, absent reasonable suspicion, detaining an individual, after completing the tasks directly tied to the traffic infraction for which they were stopped, constitutes an unreasonable seizure under the Fourth Amendment of the U.S. Constitution.

Training Points: This ruling affects police officers’ conduct during routine traffic stops. While regular tasks associated with a traffic stop, such as checking drivers’ license, running names for outstanding warrants and discussing the violation with the individual, are considered part of a routine investigation, officers should be aware that extending a traffic stop for any purpose unrelated to the investigation of the traffic citation may not survive a Fourth Amendment challenge. The additional actions can be viewed as an unreasonable seizure unless officers  have reasonable suspicion to prolong the detention to investigate another crime.

Summary Analysis: In Rodriguez v. United States, a K-9 police officer stopped the defendant for driving on the shoulder of a highway, a violation of Nebraska law. After checking his driver’s license and issuing a warning, the officer asked for permission to walk his dog around the vehicle. When Rodriguez refused, the officer detained him until backup arrived, and then used the dog, who alerted to the presence of drugs in the vehicle. During a subsequent search, methamphetamine was recovered. Rodriguez moved to suppress the evidence, but both the District Court and the Eighth Circuit U.S. Court of Appeals determined the detention was too trivial an  intrusion into his personal liberty to be unlawful, and allowed the evidence to be used.

The Supreme Court disagreed, holding that the Fourth Amendment does not allow for a dog sniff after completion of a traffic stop, and absent reasonable suspicion for the search. The Court compared a traffic stop to a Terry frisk (a brief search for a concealed weapon by an officer who has reasonable suspicion a crime did or is about to occur and to protect the officer’s safety), determining that its tolerable duration is determined by the purposes of the stop, which is to address the traffic violation that warranted the stop. Authority for the seizure ends when the tasks related to the traffic infraction are — or reasonably should have been — completed. A seizure for a traffic violation justifies only a police investigation of that specific violation, the Court reasoned, and the seizure remains lawful only so long as unrelated inquiries do not measurably extend the duration of the stop. While an officer may conduct unrelated checks during an otherwise lawful stop, he may not do so in a way that lengthens the stop absent the reasonable suspicion ordinarily required to justify detaining an individual.

Rodriguez clarifies the limits of police authority during a routine traffic stop. Officers are within their rights to conduct checks and to ask questions of individuals unrelated to the purposes of the stop only so long as that investigation does not prolong the stop. The critical question is not when the ticket is issued (i.e. before or after a dog sniff occurs), but whether conducting the sniff adds time to the stop without the necessary reasonable suspicion for detaining an individual.