Carpenter v. United States
Headline: Long-term cell‑phone location records now generally require a warrant, the Court rules, limiting police access to detailed location histories held by wireless carriers and protecting people’s everyday movements.
Holding: The Court held that the Government’s seizure of historical cell‑site location records was a Fourth Amendment search and that such records are generally obtainable only with a warrant supported by probable cause.
- Police generally must get warrants for historical cell‑phone location records.
- Limits prosecutors’ access to wireless carriers’ detailed location databases.
- May affect prosecutions that used long-term location data as key evidence.
Summary
Background
A man named Timothy Carpenter was investigated after several armed robberies. The FBI asked judges for orders under the Stored Communications Act to get the two wireless carriers’ historical cell‑site location information (CSLI) for his phone. The carriers produced 12,898 location points spanning 127 days. Prosecutors used those records at trial to place Carpenter near several robberies and he was convicted; a lower court rejected Carpenter’s effort to suppress the data because he had shared location information with his carriers.
Reasoning
The main question was whether getting years of a person’s past CSLI is a search. The Court said yes. It explained that historical CSLI is detailed, encyclopedic, and can let the Government retrace a person’s movements over long periods—so it intrudes on the privacy of a person’s physical movements. The Court declined to extend past cases that allowed the Government to get other kinds of business records from third parties, saying CSLI is different because phones constantly and automatically reveal location information. The Court held that the Government will generally need a warrant supported by probable cause to get historical CSLI; the lower standard in the Stored Communications Act (a judge’s order showing “reasonable grounds” of relevance) is not enough. The opinion was careful to be narrow and said exceptions such as exigent circumstances may still allow warrantless access.
Real world impact
Moving forward, police and prosecutors will usually need a warrant to obtain historical cell‑site records held by carriers. That changes the routine investigatory process for location data and makes judicial review with probable‑cause findings the normal path for these records. The ruling does not resolve real‑time tracking, tower dumps, national‑security collection, or every kind of third‑party record; lower courts will sort those issues later.
Dissents or concurrances
Several Justices disagreed. Dissenting opinions argued the Court upended long‑standing rules about third‑party business records and compulsory process, and warned the decision will hamper ordinary criminal investigations and create uncertainty about subpoenas and other investigative tools.
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