When a police dog jumps into a car, is that a search?

Detector dog sniffs during traffic stops are common. But the line is clear: The dog is legally allowed to sniff the exterior of the vehicle. It cannot be used as a tool to physically invade the vehicle's interior without probable cause. In this case, a detector dog briefly jumped onto a car and partially sniffed through an open window. Did that become an unlawful search?

In Mercer County, Kentucky, Deputy Michael Raisor received an anonymous tip that Steven Fellmy was allegedly trafficking drugs in his silver Ford Mustang. The deputy later spotted a vehicle matching the description and conducted a traffic stop for a non-illuminated license plate and failure to signal. After backup arrived, the deputy ordered Fellmy out of the car. (In Pennsylvania v. Mimms, the Supreme Court said officers may always order drivers out of their car during a lawful traffic stop.)

Fellmy declined the deputy's request for consent to search. So, officers deployed a trained drug detector dog around the exterior of the vehicle. During the sniff, the dog briefly jumped up on the driver's door, moving its nose near or slightly into the open window. After the dog alerted, officers searched the car and found methamphetamine and heroin. Fellmy moved to suppress.

The Supreme Court has drawn a distinction between sniffing the exterior of a vehicle in a public place and physically intruding into the interior. An exterior sniff by a trained narcotics dog is not a Fourth Amendment search. But if officers cause or encourage a dog to intrude into the interior space of the vehicle, that can cross the line. The key question becomes: Was the intrusion officer-created or dog-instinctive?

The trial court found the deputies did not prompt the dog to enter the vehicle. They did not open doors or manipulate windows to facilitate entry. The dog's jump was brief and instinctive. The appellate court agreed.

The court emphasized there was no evidence deputies encouraged or facilitated the dog's contact with the interior. The dog's brief jump onto the door and partial sniff through the open window did not transform the exterior sniff into a constitutional search. The difference is subtle but important. Passive, instinctive canine behavior during a lawful exterior sniff does not automatically equal a Fourth Amendment violation. Officer-induced intrusion does.