Concurrence
The concurring justices agreed with Justice Scalia’s rationale, but they also said that using a drug-sniffing dog on the front porch violated Jardines’ reasonable expectation of privacy. Traditionally, courts have decided that there are special protections around people’s homes. Homeowners can reasonably expect the things that are inside to be kept private. Even though visitors can approach a home, they cannot use a tool to investigate what is inside, because that might enable the visitor to know things the homeowner expected to keep private. Taking a drug-sniffing dog to a front door could allow a person to know what is inside a house, like the thermal-imaging device in Kyllo. Therefore, using a drug-sniffing dog on someone’s home is a search and, without a properly executed warrant, a violation of his Fourth Amendment rights.