This week, the U.S. Supreme Court considered the question of how long is too long for a traffic stop. A man was stopped for weaving on the road. The officer gave him a warning, but decided after that he should have a drug-sniffing dog check out the car. The dog, of course, alerted to the presence of drugs and the man was arrested.
The Court had difficulty with the question of whether the additional time necessary for the dog-sniff was constitutionally permissible. The problem with this case is that it appeared to involve both of the rationales for traffic stops, the violation of a traffic law and a stop based on reasonable suspicion. Except here, the officer did not appear to have an articulable suspicion.
The initial reason for the stop was the driver violating a traffic safety law. The officer apparently then grew suspicious of the two men in the car after speaking to them and brought the dog in to check for drugs.
From the perspective of the traffic law violation, there was no justification for the dog-sniff, so any time waiting for that was beyond the scope of that action.
The circumstance of the stop likely contributed to the suspicion: midnight, rural road in Nebraska, 2 men in the vehicle, the overwhelming scent of air freshener.
The officer appears to have become suspicious, but without having a reasonable suspicion, otherwise, why would he have needed to execute a dog sniff?
The problem with this case, which the court only tangentially approached in oral argument, is whether a dog-sniff is a search within the scope of the Fourth Amendment. It is difficult to see theoretical reasons why a dog-sniff is not a search, but a thermal imaging device directed at a home is a search.
If the officer had had an articulable, reasonable suspicion, the court would not have been struggling with questions of what is a reasonable duration for a traffic stop and how long can it be extended to allow a dog-sniff.
The oral arguments left no clear impression of how the Court may rule.
Scotusblog.com, "Argument analysis: What exactly is a "routine" traffic stop, and should a suspicionless dog sniff be part of it?" Rory Little, January 22, 2015