The 4th: Search
A search occurs when an individual’s reasonable expectation of privacy has been infringed.
“A search occurs when ‘an expectation of privacy that society is prepared to consider reasonable is infringed.’”
Maryland v. Macon, 472 U.S. 463, 469 (1985) (citation omitted)
“When officers ‘physically occup[y] private property for the purpose of obtaining information,’ a search has occurred. The majority in Jones explained:
Whatever new methods of investigation may be devised, our task, at a minimum, is to decide whether the action in question would have constituted a ‘search’ within the original meaning of the Fourth Amendment. Where, as here, the Government obtains information by physically intruding on a constitutionally protected area, such a search has undoubtedly occurred. [S]ee also 565 U.S. at 413, 132 S.Ct. at 954, 181 L.Ed.2d at 923 (Sotomayor, J., concurring) (‘I join the Court's opinion because I agree that a search within the meaning of the Fourth Amendment occurs, at a minimum, [w]here, as here, the Government obtains information by physically intruding on a constitutionally protected area.’); United States v. DE L'Isle, 825 F.3d 426, 431 (8th Cir. 2016) (‘It is clear that a physical intrusion or trespass by a government official constitutes a search within the meaning of the Fourth Amendment.’); United States v. Perea-Rey, 680 F.3d 1179, 1185 (9th Cir. 2012) (‘Warrantless trespasses by the government into the home or its curtilage are Fourth Amendment searches.’). Cf. Jackson, 728 F.3d at 373 (affirming ‘the district court's conclusion that the officers' actions did not involve an unlicensed physical intrusion of a constitutionally protected area’ and thus was not ‘an illegal search or seizure’ and noting ‘if [the officers] breached the curtilage of Cox's apartment ..., it would be fairly clear that their actions ... would implicate the protections of the Fourth Amendment’).”
State v. Bash, 419 S.C. 263, 271–72 (2017) (citation and quotations omitted).
“The Fourth Amendment to the United States Constitution prohibits unreasonable searches and seizures through its exclusionary rule. U.S. Const. amend IV. ‘A search compromises the individual interest in privacy; a seizure deprives the individual of dominion over his or her person or property.’ An individual in a private residence normally expects privacy, free of governmental intrusion not authorized by a warrant, and society recognizes this as a justifiable expectation. As such, a warrantless search is inherently unreasonable, and thus, it violates the Fourth Amendment's prohibition against unreasonable searches and seizures.”
State v. Dobbins, 420 S.C. 583, 591 (Ct. App. 2017).
Knock and Talk
“‘A license may be implied from the habits of the country,’ notwithstanding the ‘strict rule of the English common law as to entry upon a close.’ 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 path, knock promptly, wait briefly to be received, and then (absent invitation to linger longer) leave. Complying with the terms of that traditional invitation does not require fine-grained legal knowledge; it is generally managed without incident 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.” Fla. v. Jardines, 569 U.S. 1, 8–9 (2013) (citations omitted)
 Maryland v. Macon, 472 U.S. 463, 469 (1985)