Last December, this blog discussed a story where police used a trained dog to sniff a car seeking evidence of drugs during a Novato, California traffic stop. Courts generally have held that a dog-sniff outside a car is not a search within the meaning of the Fourth Amendment, and therefore police do not need to obtain a warrant before using a dog outside a car. But the United States Supreme Court ruled Tuesday that the legal analysis is different outside the front door of a home.

The issue rose to the high court on an appeal from a drug crime case out of Florida. The state high court had ruled that drugs discovered after police brought a trained drug sniffing dog to a home without a warrant were not admissible in a criminal trial against a resident of the home. Prosecutors appealed to the U.S. Supreme Court.

In the case, police say that they had received a tip that a marijuana growing operation was going on inside the home. An investigator brought his K-9 to the home and had the dog sniff the base of the front door.

Law enforcement claims the drug sniffing dog alerted outside the home. Police used that information to obtain a search warrant. Police raided the home and seized 25 pounds of pot. However, the U.S. Supreme Court ruled Tuesday that law enforcement cannot conduct the dog-sniff operation outside a residence without first obtaining a warrant.

Justice Antonin Scalia was joined by justices Thomas, Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan in finding that a warrantless dog sniff outside a residence violates constitutional protections against unreasonable government intrusions. The high court says that a dog-sniff for contraband in front of a home constitutes a search for the purposes of Fourth Amendment analysis.

Generally, courts hold a high standard for Fourth Amendment issues in cases involving a home. Justice Kagan wrote a concurring opinion which says that such a search outside a home is a violation of a person's privacy rights, an issue that Justice Scalia did not reach.

Four justices dissented from the ruling of the majority. Justice Samuel Alito says that a reasonable person would know that smells would escape from the house, which could be detected in a public case.

Tuesday's ruling was the second handed down this term in dog sniffing cases. In February, the court upheld a warrantless dog-sniff outside a pickup truck that led to the discovery of drug manufacturing ingredients.

Source: Reuters, "Supreme Court limits police use of drug-sniffing dogs," Jonathan Stempel, March 26, 2013