Facts
- Federal agents suspected Danny Lee Kyllo of growing marijuana inside his residence, a triplex unit in Florence, Oregon.
- Indoor marijuana cultivation often uses high-intensity lamps that generate unusual heat patterns.
- At about 3:20 a.m. on January 16, 1992, an agent used an Agema Thermovision 210 thermal imager from across the street to scan the exterior of Kyllo’s home.
- The thermal scan indicated portions of Kyllo’s home were relatively warmer than surrounding areas and neighboring units.
- Agents relied on informant tips, utility-usage information, and the thermal imaging results to obtain a warrant from a federal magistrate judge.
- Execution of the warrant revealed an indoor marijuana-growing operation with more than 100 plants.
- Kyllo was indicted for manufacturing marijuana in violation of 21 U.S.C. § 841(a)(1).
- The district court denied Kyllo’s motion to suppress, finding the device was non-intrusive, emitted no rays, could not penetrate walls, and did not reveal activities or other details inside the home.
- After a conditional guilty plea preserving the suppression issue, the Ninth Circuit ultimately affirmed, reasoning that the imaging did not reveal “intimate details” and that Kyllo had not meaningfully concealed the heat escaping from the home.
Issues
- Whether using a thermal-imaging device from a public vantage point to detect heat patterns associated with the interior of a home constitutes a “search” under the Fourth Amendment.
- Whether sense-enhancing technology not in general public use may be used without a warrant to obtain information about a home’s interior that otherwise could not be obtained without physical entry.
Decision
- The Supreme Court reversed the Ninth Circuit in a 5–4 decision.
- The Court held that the thermal imaging of Kyllo’s home constituted a Fourth Amendment “search.”
- The Court ruled that when the government uses a device not in general public use to obtain information about the interior of a home that previously could not have been obtained without physical intrusion, the surveillance is a search.
- Because the thermal scan was conducted without a warrant, it was presumptively unreasonable.
- The case was remanded for further proceedings consistent with the Court’s holding.
Legal Principles
- The home receives the highest level of Fourth Amendment protection; warrantless searches of a home are generally unreasonable absent an established exception.
- Use of sense-enhancing technology to obtain information regarding the interior of a home that could not otherwise be obtained without physical intrusion constitutes a search when the technology is not in general public use.
- Fourth Amendment protection in the home is not limited to what a court later characterizes as “intimate details”; governmental acquisition of interior information is the relevant concern.
- Observation from a lawful public vantage point does not, by itself, eliminate Fourth Amendment protection when technology is used to infer details of the home’s interior that would otherwise remain unknown without entry.
Conclusion
The Court held that warrantless thermal imaging of a residence using technology not in general public use is a Fourth Amendment search when it yields information about the home’s interior that could not otherwise be obtained without physical intrusion, making such surveillance presumptively unreasonable without a warrant.