Danny Lee Kyllo v. United States

Decided June 11, 2001. Antonin Scalia delivered the opinion of the Court.

Docket 99-8508 · 533 U.S. 27 (2001) · Cited 1,834 times

Holding

Where, as here, the Government uses a device that is not in general public use, to explore details of a private home that would previously have been unknowable without physical intrusion, the surveillance is a Fourth Amendment “search,” and is presumptively unreasonable without a warrant.

The Court’s statement of the holding, from the opinion’s syllabus. The syllabus is prepared by the Reporter of Decisions and is not part of the opinion of the Court — read the official opinion for authority.

How the Justices voted

Decided 5–4.

“Concurring” means agreeing with the outcome; any split shown is the Court’s judgment, not each Justice’s reasoning. Source: the Supreme Court Database (Spaeth et al.), Washington University.

Precedents cited

Supreme Court decisions this opinion relies on, ordered by how often it cites each. Cases in our collection link through; others are named.

• Katz v. United States · 389 U.S. 347 (1967)
• California v. Ciraolo · 476 U.S. 207 (1986)
• United States v. Karo · 468 U.S. 705 (1984)
• Silverman v. United States · 365 U.S. 505 (1961)
• Payton v. New York · 445 U.S. 573 (1980)
• California v. Greenwood · 486 U.S. 35 (1988)
• Smith v. Maryland · 442 U.S. 735 (1979)
• Florida v. Riley · 488 U.S. 445 (1989)
• Dow Chemical Co. v. United States Ex Rel. Administrator · 476 U.S. 227 (1986)
• Rakas v. Illinois · 439 U.S. 128 (1978)
• United States v. Place · 462 U.S. 696 (1983)
• Minnesota v. Carter · 525 U.S. 83 (1998)
• Air Pollution Variance Bd. of Colo. v. Western Alfalfa Corp. · 416 U.S. 861 (1974)
• Carroll v. United States · 267 U.S. 132 (1925)
• Boyd v. United States · 116 U.S. 616 (1886)
• United States v. Jacobsen · 466 U.S. 109 (1984)
• Illinois v. Rodriguez · 497 U.S. 177 (1990)
• Olmstead v. United States · 277 U.S. 438 (1928)
• Oliver v. United States · 466 U.S. 170 (1984)
• United States v. United States District Court for the Eastern District of Michigan · 407 U.S. 297 (1972)
• Arizona v. Hicks · 480 U.S. 321 (1987)
• Goldman v. United States · 316 U.S. 129 (1942)

Cited by

Later Supreme Court opinions in our collection that cite this case.

• Florida v. Jardines · 569 U.S. 1 (2013)
• Carpenter v. United States · 585 U.S. 296 (2018)
• Illinois v. Caballes · 543 U.S. 405 (2005)
• District of Columbia v. Heller · 554 U.S. 570 (2008)
• Fernandez v. California · 571 U.S. 292 (2014)
• Davis v. Washington · 547 U.S. 813 (2006)
• Groh v. Ramirez · 540 U.S. 551 (2004)
• Hudson v. Michigan · 547 U.S. 586 (2006)
• Kentucky v. King · 563 U.S. 452 (2011)
• Georgia v. Randolph · 547 U.S. 103 (2006)
• Torres v. Madrid · 592 U.S. 306 (2021)

Official text

Read the official opinion (U.S. Reports, govinfo.gov)

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Source: Supreme Court of the United States, slip opinions (2001). Citation count from the Free Law Project’s CourtListener bulk data. Data last verified 2026-07-03. Informational only; verify against the primary source before relying. Not a consumer report (FCRA).