In Florida v. Jardines, 11-564 (March 26, 2013), in a 5-4 decision, the United States Supreme Court affirmed suppression of evidence of marijuana obtained in violation of the Fourth Amendment. After an unverified tip that Jardines was growing marijuana in his home, police observed the home for 15 minutes, saw no movement and could not see into the house through drawn blinds. The police then brought a drug-sniffing dog onto the porch who ran around on a 6-foot leash and positively identified the odor of marijuana, with the door to the home as the strongest point source of the odor. Based on these observations, officers obtained a search warrant. The Court held that the porch is the curtilage of the home which enjoys protection as part of the home itself. Entry onto the porch with a trained drug-sniffing dog to find incriminating evidence was an unlicensed physical intrusion outside the scope of social custom. The officers’ purpose in entering the porch is relevant to whether they had an implied license to be there. Regardless of whether the investigation violated Jardines’ expectation of privacy under Katz v. United States, 389 U.S. 347 (1967), the officers’ conduct intruded upon the “property rights baseline” of the Fourth Amendment. Three concurring justices would have affirmed the suppression on privacy and property grounds.
In an opinion written by Justice Scalia, the Court held that a dog sniff at the front door of a house where the police suspected drugs were being grown constitutes a search for purposes of the Fourth Amendment.

Justice Scalia’s opinion for the Court resolved the Fourth Amendment question solely on property rights grounds, holding that bringing a dog to conduct a forensic search on someone’s porch constitutes a trespass at common law and constitutes a search subject to the limitations of the Fourth Amendment. While the general public, including the police, generally have license to approach a house’s front door (for example, to leave a flier or ask the occupant to answer a question), that license does not include an invitation to bring a dog onto the porch to search for drugs. If a member of the public did that, Justice Scalia observed, it would “inspire most of us to – well, call the police.” For that reason, the majority decision found it unnecessary to decide whether the dog sniff also violated the suspect’s reasonable expectation of privacy. When the police trespass onto private property to conduct a search, the Fourth Amendment applies regardless of whether the trespass also invades someone’s reasonable expectation of privacy.

The Jardines opinion applies to searches conducted by New Jersey police officers and other New Jersey law enforcement officers. As a result of this opinion, New Jersey authorities are prohibited from trespassing on private property in order to obtain evidence against individuals for use in the New Jersey Superior Court, New Jersey Municipal Court, and the New Jersey Federal Court.