The Minnesota Supreme Court has upheld the use of a drug-sniffing dog to detect marijuana in an apartment based on an "articulable suspicion" rather than the "probable cause" usually required to search someone's home. The police in this case brought in a dog after maintenance workers reported seeing that the tenant of an apartment where they thought they saw grow lights would not let them in to fix a leak. Based on that information, the defendant's criminal record, and the dog's reaction outside his apartment, the police obtained a search warrant. The court ruled that the maintenance workers' suspicions were enough to justify the "minimal" intrusion represented by walking the dog down a public hallway outside the apartment. The dissenters warned:
This case marks a significant departure from our constitutional jurisprudence because it is the first time the court has authorized the search of a private residence based on anything less than probable cause in the absence of exigent circumstances. It is a departure that takes us down a road that erodes Fourth Amendment protections in one's home.
I've written about dog sniffs in public places, which the U.S. Supreme Court does not consider a search requiring probable cause, and infrared readings of homes, which it does. In the January issue of reason, Julian Sanchez expanded on the theme by considering the constitutional conundrums posed by "pinpoint searches."