California v. Ciraolo

Background

On September 2, 1982, police received an anonymous tip that marijuana was growing in a homeowner’s backyard. The yard was enclosed by a 6-foot outer fence and a 10-foot inner fence and bordered the house. A police officer chartered a private plane, flew over the property at 1,000 feet in navigable public airspace, and, with another trained officer, identified and photographed tall plants in a 15-by-25 plot. An affidavit describing these observations supported a warrant, and a later search seized 73 marijuana plants.

Reasoning

The Court assumed the yard fell within the home’s curtilage but asked whether a person reasonably expects privacy from what any member of the public could lawfully see from the air. Because the officers observed the plants with the naked eye from public navigable airspace at 1,000 feet without physically entering the property, the Court held that the homeowner’s expectation of privacy was unreasonable and that the aerial observation could validly support a warrant.

Real world impact

The ruling permits police to rely on plain‑view aerial observations from lawful public airspace to investigate outdoor activity that is visible from above. Homeowners who enclose yards but leave activities exposed to the sky should expect less constitutional protection against naked‑eye overflights. The Court also signaled that more invasive technology or closer physical intrusions could produce a different result.

Dissents or concurrances

Four Justices dissented, warning that purposeful, targeted police overflights intrude on the curtilage and that Katz’s reasonable‑expectation test supports requiring a warrant for such surveillance; they argued the decision weakens household privacy protections.