Caseflicks

Supreme Court of the United States • 2018

Carpenter v. United States

585 U.S. 296 | 138 S. Ct. 2206 | 201 L. Ed. 2d 507 | 2018 U.S. LEXIS 3844

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Takeaway

In short, Carpenter holds that police generally need a probable-cause warrant to obtain extensive historical cell-phone location records, because CSLI provides a deeply revealing and automatically generated record of a person’s movements despite being held by a third-party carrier.

Background

After investigators arrested several men involved in a string of Radio Shack and T-Mobile robberies, one suspect identified Timothy Carpenter as an accomplice and supplied his cell-phone number. Using orders issued under §2703(d) of the Stored Communications Act, the Government obtained historical cell-site location information (CSLI) from Carpenter’s wireless carriers rather than a warrant supported by probable cause.

The carriers produced 12,898 location points over 127 days, averaging 101 points per day. At trial, an FBI agent used the data to place Carpenter’s phone near four robbery sites at the relevant times. Carpenter moved to suppress the CSLI, arguing that the Government had conducted a warrantless Fourth Amendment search. The District Court denied the motion, Carpenter was convicted, and the Sixth Circuit affirmed on the ground that he had voluntarily conveyed the information to his carriers and thus lacked a reasonable expectation of privacy in it.

Issues

Issue #1

Whether the Government conducts a Fourth Amendment search when it acquires at least seven days of a person’s historical CSLI from a wireless carrier.

Holding

Yes. The Government’s acquisition of Carpenter’s historical CSLI was a Fourth Amendment search.

Reasoning

The Fourth Amendment protects both property interests and reasonable expectations of privacy. Although the Amendment was shaped by the Founding-era concern with arbitrary governmental intrusion, its protections must be applied in a way that preserves meaningful privacy against new surveillance technologies. Under Katz, a governmental intrusion is generally a search when it invades an expectation of privacy that society is prepared to recognize as reasonable.

Historical CSLI sits at the intersection of two prior lines of cases. In Knotts and Jones, the Court considered location tracking, and five Justices in Jones recognized that long-term GPS monitoring can invade privacy in the whole of a person’s movements. In Miller and Smith, the Court held that people ordinarily lack a Fourth Amendment interest in bank and dialed-number records voluntarily conveyed to a third party. CSLI does not fit neatly within either line of precedent.

CSLI creates an unusually revealing, comprehensive, and easily assembled chronicle of a person’s life. A cell phone generally travels with its owner everywhere, including private homes, doctors’ offices, religious institutions, and political meetings. By examining 127 days of CSLI, the Government could reconstruct Carpenter’s past movements with a surveillance capacity that is cheap, retrospective, and close to continuous—effectively resembling an ankle monitor attached to the user.

The Court declined to extend the third-party doctrine mechanically to CSLI. Unlike checks in Miller or the limited dialed-number data in Smith, CSLI can reveal an exhaustive record of physical movements. Its collection is also not meaningfully voluntary: modern cell phones are indispensable to daily life, and the phone generates location records automatically whenever it connects to the network, without an affirmative act beyond turning the phone on.

The holding was deliberately narrow. The Court did not decide whether a shorter period of CSLI collection is a search, though it held that the Government’s request for seven days of records crossed the constitutional line. It also did not resolve questions about real-time CSLI, tower dumps, security cameras, other business records that may reveal location, or surveillance involving foreign affairs or national security.

Issue #2

Whether the Stored Communications Act’s §2703(d) order procedure satisfies the Fourth Amendment standard for obtaining Carpenter’s historical CSLI.

Holding

No. The Government generally must obtain a warrant supported by probable cause before compelling a carrier to disclose historical CSLI.

Reasoning

Once the Court concluded that obtaining CSLI is a search, the ordinary Fourth Amendment rule applied: law enforcement generally needs a warrant supported by probable cause when searching for evidence of ordinary criminal wrongdoing. Section 2703(d) required only specific and articulable facts showing reasonable grounds to believe the records were relevant and material to an ongoing investigation. That standard falls substantially short of probable cause.

The Court rejected the argument that the Government’s use of compulsory process rather than a physical search eliminated the warrant requirement. The Court had never held that the Government may subpoena a third party for records in which the suspect has a reasonable expectation of privacy. CSLI, which can reveal a detailed multiyear record of a person’s movements, is unlike ordinary corporate ledgers and other business records traditionally obtainable by subpoena under less demanding standards.

The ruling does not require probable cause for every order compelling documents from a third party. The Court characterized CSLI as the unusual case in which a person has a legitimate privacy interest in records held by another. Law enforcement may still use subpoenas and statutory orders for the overwhelming majority of ordinary third-party records.

The Court also preserved established exceptions to the warrant requirement. Exigent circumstances, such as pursuing a fleeing suspect, responding to an active threat, preventing imminent harm, or addressing a child abduction, can justify warrantless access to CSLI when the emergency makes obtaining a warrant impracticable.

Dissents

Justice Kennedy

Reasoning

Justice Kennedy argued that Miller and Smith controlled because the cell-site records were created, owned, possessed, and controlled by the wireless carriers, not by Carpenter. In his view, Carpenter neither owned nor possessed the carriers’ records and had no sufficient property-based connection to assert a Fourth Amendment interest in them.

He maintained that the third-party doctrine does not require a category-by-category balancing of the sensitivity of information. Bank records, credit-card statements, telephone records, and other business records can reveal intensely personal facts, yet Miller and Smith permit their acquisition through lawful compulsory process. Treating CSLI differently therefore creates an illogical line between types of business records.

Justice Kennedy also emphasized that the Stored Communications Act imposed a judicial check: a neutral magistrate had to find specific and articulable facts establishing reasonable grounds that the requested records were relevant and material to an ongoing investigation. That authorization, he argued, distinguished this case from the indiscriminate, suspicionless dragnet surveillance discussed in Knotts and from the warrantless GPS monitoring in Jones.

He warned that the majority’s multifactor approach—focused on sensitivity, comprehensiveness, cost, retrospectivity, and voluntariness—would be difficult for police and lower courts to administer. It would threaten a valuable investigative tool, especially at early stages of investigations where CSLI may help develop the probable cause needed for a warrant.

Justice Thomas

Reasoning

Justice Thomas argued that the Fourth Amendment should turn on whose property the Government searched. Its text protects people in their own persons, houses, papers, and effects. Because Carpenter did not create, maintain, control, or have a recognized property right in the carriers’ CSLI records, the Government searched the carriers’ property rather than Carpenter’s.

He criticized the Katz reasonable-expectation-of-privacy test as unsupported by the Fourth Amendment’s text or original history. In his view, the test replaces the Amendment’s concrete protection of persons, houses, papers, and effects with an open-ended judicial inquiry into privacy expectations and policy preferences.

Justice Thomas concluded that the Telecommunications Act’s limits on carrier disclosure did not transform the carriers’ business records into Carpenter’s property. A statutory confidentiality obligation may protect privacy, but it does not by itself give the customer ownership, possession, control, or a property-law claim over the records.

He would reconsider Katz rather than expand it. Until then, he agreed with the other dissenters that existing precedent did not support treating the Government’s acquisition of carrier-owned CSLI as a search of Carpenter.

Justice Alito

Reasoning

Justice Alito distinguished an actual search from compulsory production of documents. A physical search permits government officers to enter private premises, inspect spaces and papers, and seize evidence. A subpoena or similar order instead directs the recipient to search its own records and produce specified material, leaving the recipient an opportunity to object before complying.

In his historical account, subpoenas duces tecum and grand-jury compulsory process were familiar at the founding and were not treated as Fourth Amendment searches. The Fourth Amendment was directed principally at physical intrusions, such as general warrants and writs of assistance that allowed officers to ransack homes and papers.

Modern precedent, he argued, recognizes a limited Fourth Amendment reasonableness review for subpoenas, but not the warrant-and-probable-cause standard applicable to actual searches. Under Oklahoma Press, a document-production order need only be sufficiently specific, relevant, and not unduly burdensome. The Stored Communications Act’s requirement of specific and articulable facts, judicial approval, relevance, and materiality satisfied that standard.

Justice Alito further argued that Carpenter had no right to challenge the search of records belonging to his carriers. The Fourth Amendment protects a person’s own papers and effects, and the Telecommunications Act’s customer-access and confidentiality provisions did not give Carpenter ownership or meaningful control of CSLI. He warned that the majority’s rule could destabilize grand-jury, legislative, and administrative subpoenas and generate extensive litigation.

Justice Gorsuch

Reasoning

Justice Gorsuch agreed that Smith and Miller were wrongly reasoned and that their categorical third-party doctrine is poorly suited to a world in which people entrust vast quantities of personal information to internet and communications companies. He criticized the doctrine’s claim that people assume the risk of government access merely by sharing information with a service provider.

He nevertheless disagreed with the majority’s decision to retain Katz while adding a new, multifactor privacy analysis. In his view, Katz’s reasonable-expectation-of-privacy test lacks clear textual grounding, invites judicial policy judgments, and gives lower courts little guidance about how to balance privacy, law-enforcement needs, data sensitivity, duration, and technological change.

Justice Gorsuch urged a return to the Fourth Amendment’s more traditional focus on whether the Government searched a person’s own papers or effects. Property law, bailment principles, and positive law may establish that a person retains a protected interest even when a third party holds the item or data. For example, a sealed letter held by the Postal Service remains the sender’s protected paper.

He thought Carpenter might have had a promising argument that CSLI was his protected paper or effect because federal law grants customers certain rights to control access to customer proprietary network information. But Carpenter had primarily litigated Katz and did not adequately develop a property-based or positive-law argument. Justice Gorsuch therefore concluded that Carpenter had forfeited that possible claim and dissented.