## Facts

- Law enforcement suspected Antoine Jones of narcotics trafficking and sought authority to install a GPS tracking device on a Jeep registered to Jones’s wife.
- A warrant authorized installation in the District of Columbia within 10 days, but agents installed the device in Maryland on the 11th day.
- Agents used the device to monitor the Jeep’s movements continuously for 28 days, producing extensive location records used to connect Jones to alleged drug activity.
- The district court suppressed GPS-derived evidence collected while the vehicle was parked at Jones’s residence but admitted the remaining tracking data from public streets.
- Jones was convicted of drug-trafficking conspiracy and sentenced to life imprisonment.
- The court of appeals reversed, holding that warrantless GPS monitoring violated the Fourth Amendment.

## Issues

1. Whether the government’s attachment of a GPS device to a vehicle and use of it to monitor the vehicle’s movements constitutes a “search” under the Fourth Amendment.

## Decision

- The Supreme Court affirmed the court of appeals and held unanimously that the attachment and use of the GPS device constituted a Fourth Amendment search.
- The Court reasoned that the government physically intruded on a constitutionally protected “effect” (the vehicle) to obtain information.
- The Court did not decide whether the search was reasonable or whether a warrant is always required for similar GPS monitoring.
- Concurring opinions agreed the conduct violated the Fourth Amendment but differed on rationale: one emphasized risks from aggregated long-term monitoring under privacy expectations; another focused on the duration of surveillance rather than trespass.

## Legal Principles

- A Fourth Amendment search occurs when the government physically intrudes on a protected area (persons, houses, papers, or effects) for the purpose of obtaining information.
- The reasonable-expectation-of-privacy test supplements, rather than replaces, the trespass-based approach.
- Technology-enabled, prolonged monitoring may raise distinct Fourth Amendment concerns because aggregation can reveal detailed information about a person’s life, even when individual movements occur in public.

## Conclusion

The Court held that installing a GPS device on a vehicle and using it to track movements is a Fourth Amendment search because it involves a physical intrusion on an effect to obtain information, while leaving broader questions about reasonableness and warrant requirements unresolved.


United States v. Jones, 565 U.S. 400 (2012)