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.
Curtilage Basics. Broadly speaking, curtilage is the area in the immediate proximity of a residence that can be considered part of the home. For Fourth Amendment purposes, if the area qualifies as curtilage, it is protected from warrantless search to the same extent as the home itself. “When a law enforcement officer physically intrudes on the curtilage to gather evidence of a crime, a search within the meaning of the Fourth Amendment occurs.” Collins v. Virginia, 584 U.S. 586, 593 (2018) (internal citation omitted). Areas in the immediate vicinity of the home and closely connected to the home like driveways, porches, and patios will generally qualify as curtilage, but questions arise about where to draw the line, especially in contexts other than stand-alone residences. In U.S. v. Dunn, 480 U.S. 294, 301 (1987), the Supreme Court articulated a four-factor balancing test for determining whether an area qualifies as Fourth Amendment curtilage. Under Dunn, a court must consider “the proximity of the area claimed to be curtilage to the home, whether the area is included within an enclosure surrounding the home, the nature of the uses to which the area is put, and the steps taken by the resident to protect the area from observation by people passing by.” Id. The Court further explained that the test is not to be applied “mechanically;” rather, the ultimate question is whether the area should count as part of the residence. Id.
Johnson Facts. Police suspected the defendant of distributing drugs from his apartment based on extensive surveillance and wiretapping efforts. Prior to obtaining a search warrant for the property, officers decided to conduct a canine sniff of the area just outside of his door. At 3 a.m., with the help of building management, the officers and canine conducted the sniff, with the dog putting its snout on or very near the crack between the bottom of the front door and the building floor. The dog alerted and police subsequently obtained a search warrant for the home based on the positive alert and other information. Inside, officers discovered evidence of drug distribution and an illegal gun (among other contraband), leading to Johnson’s federal prosecution.
Johnson moved to suppress the evidence found during the search. He argued in part that the canine sniff amounted to a physical trespass onto the curtilage of his home. The district court denied the motion, finding that the hallway just outside of the defendant’s apartment did not qualify as curtilage because the defendant had no ability to exclude others from that area. (The defendant also complained that the sniff violated his reasonable expectation of privacy, an argument similarly rejected by the court, but my focus is on the curtilage issue).
On appeal, a unanimous panel of the Fourth Circuit agreed. In the words of the court:
[The area where the dog sniffed] was part of a common hallway, used regularly by other building residents and by building cleaning staff. And it was not just other residents and staff; despite locks at the front door, entry to the interior hallway was not restricted in any way because building management routinely granted consent to enter upon request. Johnson could of course exclude any of those people from the interior of his apartment, but they all had the right to be in the common hallway outside his door. Johnson Slip op. at 11-12 (cleaned up) (emphasis in original).
But I Thought Police Couldn’t Do That! If the Johnson ruling surprises you, you are not alone. I seemed to remember a U.S. Supreme Court case where a dog sniff at the front door of a residence without a warrant was found to violate the Fourth Amendment. There is such a case, but the devil is in the details.
In Florida v. Jardines, 569 U.S. 1 (2013), police suspected the defendant of growing marijuana in his home. Two detectives approached the defendant’s front porch with a drug-sniffing dog, which alerted on the home’s front door. Based on the alert, police sought and obtained a search warrant for the home, leading to marijuana trafficking charges for the defendant. The defendant moved to suppress, arguing that the use of a trained canine at his front door constituted a warrantless search of his home, and therefore violated the Fourth Amendment. The defendant won that argument at the U.S. Supreme Court. The Jardines majority found that the police exceeded the scope of a normal knock-and-talk by using a canine at the front door of the home, and that this amounted to a Fourth Amendment search. While police—like other members of the public—may lawfully enter the curtilage of a home without a warrant to attempt to talk with the inhabitants, using a canine in the process was a step too far. In the words of Justice Scalia, speaking for the Court:
We have accordingly recognized that the knocker on the front door is treated as an invitation or license to attempt an entry, justifying ingress to the home by solicitors, hawkers, and peddlers of all kinds. This implicit license typically permits the visitor to approach the home by the front door, knock promptly, wait briefly to be received, and then (absent an invitation to linger longer) leave. Complying with the terms of that traditional invitation does not require fine-grained legal knowledge; it is generally managed by the Nation’s Girl Scouts and trick-or-treaters. Thus, a police officer not armed with a warrant may approach a home and knock, precisely because that is no more than any private citizen might do. But introducing a trained police dog to explore the area around the home in hopes of discovering incriminating evidence is something else. There is no customary invitation to do that. Jardines at 8-9 (cleaned up) (emphasis in original).
It is important to note that the Court did not find that the use of the canine violated the defendant’s reasonable expectation of privacy. Instead, the Court grounded its holding in traditional property law principles to find that the physical trespass of the officers onto protected curtilage amounted to a Fourth Amendment search. See, e.g., U.S. v. Jones, 565 U.S. 400 (2012) (warrantless installation of tracking device on the defendant’s car amounted to a search as a physical trespass). While Justice Kagan opined that the use of a canine in this manner also violated the defendant’s reasonable expectation of privacy, the majority expressly declined to decide that question. Jardines at 13 (Kagan, J., concurring).
So, Do Apartments Ever Have Curtilage? The Johnson court was careful to note that it was not announcing a categorical rule that apartments never have protected curtilage. “Multi-dwelling units come in all kinds of configurations, and some may include ‘common’ areas different from the apartment hallway here . . .” Johnson Slip op. at 15. Both state and federal cases have found protected curtilage in the context of multi-unit dwelling on different facts. Consider the following examples:
- State v. Reed, 182 N.C. App. 109 (2007) (back patio of defendant’s apartment shared with three other tenants, connected to the defendant’s apartment, and covered by a tarp was protected curtilage).
- State. v. Jackson, 728 F.3d 367 (4th Cir. 2013) (back patio attached the defendant’s apartment was protected curtilage).
- State. v. Hopkins, 824 F.3d 726 (8th Cir. 2016) (hallway to two units shared only by the two tenants was protected curtilage).
As the Reed and Hopkins cases above indicate, the defendant’s control over the area need not be exclusive. But when common areas of a multi-unit dwelling are accessible to all tenants of the building (or to the public at large) and the defendant lacks any real control over it, the areas are unlikely to qualify as curtilage. See, e.g., State v. Williford, 239 N.C. App. 123 (2015) (parking lot of apartment building shared by all tenants was not curtilage).
Takeaway. As with most Fourth Amendment issues, whether an area qualifies as protected curtilage is a fact-intensive inquiry. While apartments and other multi-unit residences may have areas around the unit entitled to Fourth Amendment protection as curtilage (i.e., as part of the home), Johnson is a reminder that truly common areas of the building will probably not count—even when the common area is directly in front of the apartment’s front door. As other courts have recognized, it fair to say that curtilage of a typical apartment unit will “necessarily be more limited” than that of a stand-alone home. U.S. v. Cruz Pagan, 537 F.2d 554, 558 (1st Cir. 1976).