In U.S. v. Johnson, 148 F.4th 287 (4th Cir. 2025) (summarized here), the U.S. Court of Appeals for the Fourth Circuit recently rejected a Fourth Amendment challenge to a canine sniff at the front door of the defendant’s apartment. My colleagues Jeff Welty and Shea Denning have blogged about the issue of curtilage and multi-unit dwellings like apartment buildings in the past (here, here, and here), but Johnson is a good refresher on those principles. Read on for the details.