Drug-Sniffing Dogs and the Fourth Amendment

By The New York Times | Editorial

29 March 13

he Supreme Court correctly ruled this week that using a drug-sniffing police dog on a suspect's property without a warrant violates the Fourth Amendment's protection against unreasonable searches. The ruling was not surprising; the split among the justices was.

The majority included conservative Justices Antonin Scalia and Clarence Thomas and three of the court's more liberal members (Justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan). The four dissenting justices were: Samuel Alito Jr., Anthony Kennedy and Chief Justice John Roberts Jr., all on the conservative side; and Stephen Breyer, a moderate liberal.

Even though the drug-sniffing dog in his case got no further than the suspect's front porch, Justice Scalia, writing for the majority, said that Fourth Amendment protection extends not only to a house but to its surroundings.

In a concurring opinion, Justice Kagan agreed that this dog-sniffing was an unconstitutional search, but because of the right to privacy as well as trespass. A person's home, she said, is not only his castle but "his most intimate and familiar space."

In 2001, the Supreme Court held that a person has a "minimal expectation of privacy" in his home that the police had violated when they conducted a search for marijuana using a thermal imaging device from outside the home. The Kagan concurrence points the way for a future court to emphasize this important principle again: In an era of sophisticated technology, the Constitution must keep police from using it to invade privacy - whether it is lawful for them to be on private property or not.