Supreme Court weighs geofence warrants that sweep in everyone near a crime

A geofence warrant inverts the normal process of criminal investigation. Traditionally, police identify a suspect and then ask a judge for a warrant to search that person's property or records. With a geofence warrant, police know only where and when a crime occurred. They serve the warrant on Google, which searches its Sensorvault database — a repository of location history data from hundreds of millions of Android users — and returns records for every device in the area during the relevant window.

In the Chatrie case, police investigating a May 2019 bank robbery in Midlothian, 🏛️Virginia set a geofence radius around the credit union and asked Google for data from all phones in the area over a 30-minute window. Google returned anonymized identifiers for 19 devices. Police narrowed the pool until they identified Okello Chatrie, who was convicted and sentenced to 17.5 years in prison. The Fourth Circuit upheld his conviction 2-1 on the grounds that he had voluntarily shared his location data with Google.

The government's core argument rests on the third-party doctrine — a legal principle from 1970s Supreme Court decisions holding that people lose Fourth Amendment protection over information they voluntarily share with third parties. Solicitor General DJD. John Sauer argued that when users enable Google's Location History feature, they consent to Google storing their movement data, and that consent removes any reasonable expectation of privacy. Under this theory, Google's database is no different from a bank's transaction records: data you gave to a company is fair game for law enforcement without a warrant naming a specific person.

Defense attorney Adam Unikowsky challenged that framing. He argued that no one meaningfully consents to law enforcement access when they agree to Google's terms of service, and that the voluntary sharing concept breaks down when smartphones have become essential to modern life. People can't realistically avoid location-tracking apps while still participating in work, navigation, and daily commerce. Unikowsky also argued Chatrie retains a property interest in his own location data under the Fourth Amendment's protection of papers and effects.

The Supreme Court's 2018 Carpenter v. United States decision is the controlling precedent. In that 5-4 ruling, Chief Justice John Roberts wrote that the government must obtain a warrant before accessing historical cell site location records from phone carriers — even though those records were held by a third party. Roberts held that the third-party doctrine doesn't apply when records reveal a detailed chronicle of a person's past movements over time. The Chatrie case tests whether Carpenter extends to geofence warrants, which Google holds rather than carriers and which cover a snapshot in time rather than months of continuous tracking.

The government argues Chatrie differs from Carpenter because geofence data covers a brief window and because users actively enable Location History rather than passively generating carrier records. Chatrie's lawyers counter that the breadth of Google's database and the dragnet nature of geofence warrants make them more intrusive, not less, because they expose innocent bystanders who happen to be near a crime scene.

Thirty-one states plus the 🏛️District of Columbia filed amicus briefs supporting the government's position. State attorneys general across party lines argued that geofence warrants have solved murders, sexual assaults, and armed robberies that would otherwise remain unsolved. Law enforcement groups point to the January 6, 2021 Capitol riot: federal prosecutors used geofence data to identify suspects whose phones were inside the Capitol building. Supporters argue that requiring individualized suspicion before issuing a geofence warrant would make the tool unusable.

Civil liberties groups including the Electronic Frontier Foundation, the American Civil Liberties Union, and the Electronic Privacy Information Center oppose the government. They argue that geofence warrants are categorically different from traditional warrants because they begin with no suspect and inevitably capture data from innocent people. Google itself moved to limit geofence warrants in recent years and in 2024 began shifting Location History storage from its servers to individual devices — a change that complicates future warrant requests but doesn't eliminate older stored data.

The ruling will set the constitutional framework for a surveillance tool that has grown dramatically. According to Google's transparency reports, the company received approximately 10,000 geofence warrant requests from U.S. law enforcement in 2020 alone — a more than 1,500 percent increase from 2017. Law enforcement agencies at the federal, state, and local levels have deployed the tool across a wide range of investigations. If the Court rules against Chatrie, it locks in a power with minimal individualized oversight.

If the Court rules for Chatrie, past convictions built on geofence evidence won't automatically be invalidated. The good-faith exception to the exclusionary rule protects evidence gathered by officers who acted in good faith under then-existing law. Defendants in prior cases would need to show that the unconstitutionality was so clear that reliance on existing legal authority was not reasonable. The ruling would require police to establish probable cause about specific individuals before using the tool going forward.

The April 27, 2026 oral argument exposed unusual ideological alignments on the Court. Justice Neil Gorsuch questioned Solicitor General Sauer about whether users who enable Location History actually know their data could be compiled into a complete record of their movements and handed to police. Gorsuch has long argued that digital privacy protection should rest on property rights — if location data is the user's own property, the government can't seize it from Google without a warrant naming the specific person.

Justice SSSonia Sotomayor pressed both sides on whether a sweep covering hundreds of innocent people is fundamentally different from the targeted searches the Fourth Amendment was designed to allow. Her 2012 concurrence in United States v. Jones argued that the third-party doctrine needs reconsideration in the digital era. Justice Samuel Alito, who dissented in Carpenter, challenged Unikowsky on how law enforcement would solve large-scale crimes like the January 6 Capitol riot investigation without geofence access. Chief Justice Roberts asked both sides how their proposed rule would apply to narrower data sweeps, suggesting he may be looking for a middle path.

Google's engineering decisions have complicated the legal landscape since the Chatrie case began. In December 2023, Google announced it would move Location History storage from its own servers to individual users' devices, rebranding the feature as Timeline. For data generated after that change, police can no longer serve a single warrant on Google's Sensorvault database and receive records for everyone in an area. They would need to compel data from each individual user's device separately.

The architectural change doesn't affect records already stored on Google's servers before December 2023, which include years of location history for Android users who had Location History enabled. Apple has stored similar data on-device since the iPhone's early years, which is one reason geofence warrants have primarily targeted Google rather than Apple. The Supreme Court's ruling will set Fourth Amendment standards for whatever architecture tech companies use, but the practical enforcement landscape has already shifted beneath the legal debate.