California v. Ciraolo

Incident Summary & Facts

On September 2, 1982, Santa Clara police received an anonymous tip that marijuana was growing in Dante Ciraolo’s backyard. From the ground, officers could not see into the yard, which was completely enclosed by a 6-foot outer fence and a 10-foot inner fence. That same day, Officer Shutz, accompanied by Officer Rodriguez (both trained in marijuana identification), secured a private plane and flew over the house at 1,000 feet, within navigable airspace. With the naked eye, they readily identified marijuana plants 8 to 10 feet tall in a 15-by-25-foot plot and photographed the area with a standard 35mm camera.

Officer Shutz obtained a search warrant based on an affidavit describing the tip and the aerial observations, with the photograph attached. The warrant was executed, and 73 marijuana plants were seized. After the trial court denied his motion to suppress, Ciraolo pleaded guilty to cultivation of marijuana. The California Court of Appeal reversed, holding that the warrantless, focused aerial observation of the curtilage violated the Fourth Amendment. The U.S. Supreme Court granted the State’s petition for certiorari.

The case did not involve a use-of-force encounter; it concerns warrantless aerial surveillance under the Fourth Amendment.

Core Legal Issue

Whether the Fourth Amendment is violated by warrantless, naked-eye aerial observation, from an altitude of 1,000 feet in public navigable airspace, of a fenced-in backyard within the curtilage of a home.

The Holding

By a 5–4 vote, the Court held that Ciraolo’s expectation that his yard was protected from naked-eye observation from public airspace at 1,000 feet was not one “society is prepared to honor,” so no warrant was required. The California Court of Appeal was reversed.

The Court’s Analysis:

• The Court applied the two-part Katz test: (1) whether the person showed a subjective expectation of privacy, and (2) whether society recognizes that expectation as reasonable. It did not decide the first prong, because the State did not challenge the lower court’s finding on it.
• The Court accepted that the yard was within the curtilage, where privacy expectations “are most heightened.” But curtilage status “does not itself bar all police observation.” Officers need not “shield their eyes” when passing a home on public thoroughfares. “What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection.”
• The observation took place from public navigable airspace “in a physically nonintrusive manner.” “Any member of the public flying in this airspace who glanced down could have seen everything that these officers observed.” It was irrelevant that the flight was aimed at this yard or that the officers were trained to recognize marijuana.
• The Court rejected the lower court’s distinction between “focused” surveillance and “routine patrol” overflights. Justice Harlan’s warning in Katz about electronic intrusions was “plainly not aimed at simple visual observations from a public place.”
• Dissent (Powell, J., joined by Brennan, Marshall, and Blackmun, JJ.): Under Katz, whether police physically trespassed is irrelevant. The risk of observation by ordinary air travelers is “virtually nonexistent,” and purposeful police surveillance of the curtilage is a search that requires a warrant.