Scope of the Rights Protected by the Fourth Amendment: Current Doctrine

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

The Court confirmed in Carpenter v. United States that the Fourth Amendment is implicated when government action violates individuals' “reasonable expectation of privacy in the whole of their physical movements,” regardless of whether the challenged conduct constitutes a physical trespass.5 Footnote
138 S. Ct. 2206, 2217 (2018) . The Court held that the government could not, without a warrant, access seven days of a defendant's cell-site location information, which is data that continuously tracks the location of a cell phone.6 Footnote
Id. at 2216–17 . Observing that “historical cell-site records present even greater privacy concerns than the GPS monitoring of a vehicle we considered in Jones ,” the Court highlighted the continuing importance of the expectations-of-privacy test.7 Footnote
Id. at 2218 . The Court acknowledged that it had previously declined to extend Fourth Amendment protection to information that a person had voluntarily given to a third party like a wireless carrier, but declined to extend that line of cases to “the qualitatively different category of cell-site records.” 8 Footnote
Id. at 2216–17 .

Footnotes 1 565 U.S. 400 (2012) . 2 Id. at 403–07 . The physical trespass analysis was reprised in subsequent opinions. In its 2013 decision in Florida v. Jardines , the Court assessed whether a law enforcement officer had the legal authority to conduct a drug sniff with a trained canine on the front porch of a suspect’s home. Reviewing the law of trespass, the Court observed that visitors to a home, including the police, must have either explicit or implicit authority from the homeowner to enter upon and engage in various activities in the curtilage (i.e., the area immediately surrounding the home). Finding that the use of the dog to find incriminating evidence exceeded “background social norms” of what a visitor is normally permitted to do on another’s property, the Court held that the drug sniff constituted a search. 569 U.S. 1, 7–10 (2013) . Similarly, in its 2015 per curiam opinion in Grady v. North Carolina , the Court emphasized the “physical intru[sion]” on a person when it found that attaching a device to a person’s body, without consent, for the purpose of tracking the person’s movements, constitutes a search within the meaning of the Fourth Amendment. 135 S. Ct. 1368, 1371 (2015) . Neither the majority in Jardines nor the Court in Grady addressed whether the challenged conduct violates a reasonable expectation of privacy under Katz v. United States . Grady , 135 S. Ct. at 1371 ; Jardines , 569 U.S. at 10–12 . 3 Jones , 565 U.S. at 400, 431 (Alito, J., concurring in the judgment, joined by Ginsburg, Breyer, Kagan, JJ.) (concluding that respondent’s reasonable expectations of privacy were violated by the long-term monitoring of the movements of the respondent’s vehicle); id. at 415 (Sotomayor, J., concurring) (disagreeing with Justice Alito’s “approach” to the specific case but agreeing “longer term GPS monitoring in investigations of most offenses impinges on expectations of privacy.” ). 4 See, e.g., In re Application for Telephone Information Needed for a Criminal Investigation, 119 F. Supp. 3d 1011, 1021–22 (N.D. Cal. 2015) (discussing the import of the two concurring opinions from Jones ); United States v. Brooks, 911 F. Supp. 2d 836, 842 (D. Ariz. 2012) (noting that “[w]hile it does appear that in some future case, a five justice ‘majority’ is willing to accept the principle that Government surveillance can implicate an individual’s reasonable expectation of privacy over time, Jones does not dictate the result of the case at hand . . .” ); but see United States v. Graham, 824 F.3d 421, 435–36 (4th Cir. 2016) (arguing that Justice Alito’s Jones concurrence should be read more narrowly so as to not implicate government access to information collected by third-party actors, no matter the quantity of information collected); In re Application of FBI , No. BR 14–01, 2014 WL 5463097, at *10 (FISA Ct. Mar. 20, 2014) ( “While the concurring opinions in Jones may signal that some or even most of the Justices are ready to revisit certain settled Fourth Amendment principles, the decision in Jones itself breaks no new ground . . .” ). 5 138 S. Ct. 2206, 2217 (2018) . 6 Id. at 2216–17 . 7 Id. at 2218 . 8 Id. at 2216–17 .

The following state regulations pages link to this page.