Also known as: canine sniffs · canine-sniff · canine-sniffs · dog sniff · K9 sniff · drug dog search
Written by attorneys · grounded in primary & secondary sources — see below
A limited investigative technique in which a trained narcotics-detection dog sniffs the exterior of a vehicle or container. The technique discloses only the presence or absence of contraband and therefore does not constitute a search under the Fourth Amendment when performed during a lawful detention that is not extended beyond the time required to complete the original mission.
Luis, a long-haul truck driver for Apex Manufacturing, stopped at a state weigh station. Inspector Harris lawfully directed Luis to a lane for a routine safety inspection. While Harris checked Luis's paperwork, Officer Reed walked her trained narcotics dog around the trailer. The sniff took under a minute, ended before Harris finished, the dog alerted, and drugs were found.
Officers developed reasonable suspicion that a traveler's luggage contained narcotics at an airport. They detained the bag briefly and exposed it to a trained narcotics-detection dog. The dog alerted, disclosing only the presence or absence of contraband without opening the luggage or revealing other contents.
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Officers at a highway checkpoint conducted a lawful vehicle stop. A narcotics dog walked the exterior of the stopped car and alerted. The alert supplied probable cause for a further search under the automobile exception.
No. A canine sniff of a vehicle's exterior during a lawful traffic stop is not a search when it does not prolong the stop. Officers therefore need no separate reasonable suspicion of drug activity to deploy the dog so long as the sniff occurs while they are still handling the original traffic matter.
Supporting sources
A canine sniff becomes unlawful when officers prolong an otherwise-completed traffic stop, even briefly, to conduct the sniff without independent reasonable suspicion. The critical question is whether the dog sniff adds time to the stop beyond what is needed to handle the traffic violation.
Supporting sources
Yes. When the government shows that a narcotics detection dog is properly trained and currently certified, the dog's alert ordinarily suffices to establish probable cause to search the vehicle under the automobile exception, absent specific evidence undermining the dog's reliability.
Supporting sources
…possesses a privacy interest in the contents of personal luggage that is protected by the Fourth Amendment. Id. , at 13. A "canine sniff" by a well-trained narcotics detection dog, however, does not require opening the luggage. It does not expose noncontraband items that otherwise would remain hidden from public view, as…