According to Florida vs. Jardines, why was the drug dog's sniff deemed an illegal search?

The determination that the drug dog's sniff constituted an illegal search in Florida vs. Jardines centers on the violation of the owner's privacy rights without a warrant. The United States Supreme Court ruled that the use of a dog to sniff for drugs outside a home is considered a search under the Fourth Amendment, which protects against unreasonable searches and seizures. The essence of the court's decision hinges on the expectation of privacy that homeowners have regarding the interior of their residence.

In this case, the court emphasized that the area surrounding a home, particularly the porch and its immediate vicinity, is considered part of the home for privacy purposes. The presence of law enforcement with a drug dog, conducting a sniff test in that area without a warrant or consent, intrudes upon that reasonable expectation of privacy. This ruling reinforces the principle that any search that violates an individual's privacy without proper legal justification—such as a warrant—can be deemed unconstitutional.