WASHINGTON — The Supreme Court on Tuesday limited the ability of the police to use drug-sniffing dogs outside homes.

The case concerned Franky, a chocolate Labrador retriever who detected the smell of marijuana outside a Florida house used by Joelis Jardines. Based on Franky’s signal, the police obtained a warrant to search the house, and they found a marijuana-growing operation inside.

Mr. Jardines moved to suppress the evidence, saying that using Franky to sniff around his residence was an unreasonable search barred by the Fourth Amendment. The Florida Supreme Court agreed, and so did a majority of the United States Supreme Court.

The 5-to-4 decision in the case, Florida v. Jardines, No. 11-564, featured an unusual alignment of justices. Justice Antonin Scalia, a member of the court’s conservative wing, wrote the majority decision. He was joined by Justice Clarence Thomas, a frequent ally, along with three of the court’s more liberal members, Justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan.