- Court
- U.S. Supreme Court
- Decided
- Citation
- 565 U.S. 400 (2012)
- Docket
- No. 10-1259
- Binding in
- Federal (nationwide)
- Status
- Held
What the court held, in plain English
Installing a GPS tracker on a vehicle and using it to monitor the vehicle’s movements is a Fourth Amendment search. The majority relied on the physical intrusion onto the vehicle. Concurring Justices added that longer-term GPS monitoring impinges on expectations of privacy, an idea later applied to digital location data.
The question
Did the government conduct a Fourth Amendment search when it attached a GPS device to a suspect’s vehicle and tracked the vehicle’s movements for four weeks?
The facts
Federal agents installed a GPS tracking device on a Jeep used by Antoine Jones, a nightclub owner suspected of drug trafficking, and tracked the vehicle’s movements for four weeks. The data helped secure his conviction. The D.C. Circuit reversed, and the Supreme Court affirmed that decision.
What the court held
Writing for the majority, Justice Scalia held that “the Government’s installation of a GPS device on a target’s vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a ‘search.’” The majority rested on the government’s physical intrusion onto private property (the vehicle) to gather information. It didn’t decide whether tracking by purely electronic means, without that intrusion, would be a search.
Justice Alito, joined by three Justices, concurred in the judgment on a different ground: “the use of longer term GPS monitoring in investigations of most offenses impinges on expectations of privacy.” Justice Sotomayor joined the majority but agreed with that point, and noted that GPS monitoring “generates a precise, comprehensive record of a person’s public movements.”
Why it matters for license plate readers
ALPR systems don’t attach anything to a vehicle, so the majority’s physical-intrusion rule doesn’t apply to them directly. The concurrences matter more. They suggested that collecting enough location data over time can intrude on privacy even when each observation happens in public. That aggregation idea, often called the mosaic theory, is central to arguments about large ALPR networks, and Massachusetts’s high court relied on it in Commonwealth v. McCarthy.
What it didn’t decide
- Whether purely electronic tracking without a physical intrusion is a search. The majority left this open.
- How long monitoring must last before it becomes a search. The Alito concurrence said the line was crossed before four weeks, but didn’t fix one.
- Anything about license plate readers.
Later history
Jones remains good law. In Carpenter v. United States (2018), the Court drew on the Jones concurrences in holding that obtaining historical cell-site location records is a search.
One ruling doesn’t settle every case. A decision binds courts within its jurisdiction, and outcomes depend on the facts. See how we summarize cases in our editorial standards.