The U.S. Supreme Court has said that having a drug-detecting dog sniff luggage at an airport or a car during a traffic stop does not amount to a "search" under the Fourth Amendment and therefore does not require a warrant. A case that Florida's attorney general has asked the Court to consider raises the question of whether the same conclusion applies to the use of a drug-sniffing dog outside a home. Miami-Dade police brought the dog to Joelis Jardines' house on December 5, 2006, based on an anonymous tip that he was growing marijuana. After sniffing around, the dog sat down, which supposedly indicated that he smelled cannabis. Based on that "alert," police obtained a search warrant from a magistrate. The ensuing search discovered 179 plants, along with Jardines sneaking out the back door. The trial court suppressed the evidence obtained in the search, agreeing with Jardines that police needed probable cause to bring in the dog. An appeals court reversed that decision, but last April the Florida Supreme Court reinstated it, concluding the dog-assisted inspection of the home's exterior did indeed constitute a search.
The U.S. Supreme Court's rulings dealing with dog sniffs emphasized that people do not have a reasonable expectation of privacy in the possession of contraband, which is the only thing a properly trained dog's alert is supposed to reveal. (Whether that's true in practice is another matter.) But the decisions were limited to specific settings (an airport and a highway) where the expectation of privacy is not as strong as it is in the home. Then again, in Kyllo v. United States, the 2001 case where the Court said a warrant is needed for infrared surveillance of a home, it emphasized that thermal imaging reveals innocent details of people's lives as well as the possible presence of an indoor marijuana garden. In light of those rulings, Tom Goldstein, publisher of SCOTUSBlog, told the Associated Press:
The Florida Supreme Court adopted a very broad reading of the Fourth Amendment that is different from that applied by other courts. It's an interpretation that a majority of the U.S. Supreme Court will question.
The Florida Supreme Court nevertheless makes a strong case that, even assuming police dogs are inerrant drug-detecting machines, a canine inspection like the one conducted at Jardines' house is not the sort of thing police should be allowed to do on a whim:
The dog "sniff test" that was conducted in the present case was an intrusive procedure. As explained more fully below, the "sniff test" was a sophisticated undertaking that was the end result of a sustained and coordinated effort by various law enforcement agencies. On the scene, the procedure involved multiple police vehicles, multiple law enforcement personnel, including narcotics detectives and other officers, and an experienced dog handler and trained drug detection dog engaged in a vigorous search effort on the front porch of the residence. Tactical law enforcement personnel from various government agencies, both state and federal, were on the scene for surveillance and backup purposes. The entire on-the-scene government activity—i.e., the preparation for the "sniff test," the test itself, and the aftermath, which culminated in the full-blown search of Jardines‟ home—lasted for hours. The “sniff test” apparently took place in plain view of the general public. There was no anonymity for the resident.
Such a public spectacle unfolding in a residential neighborhood will invariably entail a degree of public opprobrium, humiliation and embarrassment for the resident, for such dramatic government activity in the eyes of many—neighbors, passers-by, and the public at large—will be viewed as an official accusation of crime. Further, if government agents can conduct a dog "sniff test" at a private residence without any prior evidentiary showing of wrongdoing, there is nothing to prevent the agents from applying the procedure in an arbitrary or discriminatory manner, or based on whim and fancy, at the home of any citizen. Such an open-ended policy invites overbearing and harassing conduct. Accordingly, we conclude that a "sniff test," such as the test that was conducted in the present case, is a substantial government intrusion into the sanctity of the home and constitutes a "search" within the meaning of the Fourth Amendment. As such, it must be preceded by an evidentiary showing of wrongdoing.
Miami-Dade police could have avoided this whole controversy if they had taken a cue from their colleagues in Pinellas County and simply claimed they could smell the pot while standing outside Jardines' house. Perhaps their noses are not quite as sensitive. The cops in Pinellas County, after all, can smell marijuana even when it's not there.
SCOTUSblog has more on Florida v. Jardines here. More on drug-sniffing dogs here, including Radley Balko's 2011 column on "The Mind of a Police Dog." Julian Sanchez explored related issues in his classic Reason article on "The Pinpoint Search."
[Thanks to Kevin Bankert for the tip.]