US surveillance and digital privacy

After Chatrie, Police Need a Warrant Before Mining Location Data from Google — Even Briefly

The Supreme Court's 6-3 ruling extends Fourth Amendment protection to app-generated location records held by third parties, closing the gap Carpenter left open in 2018.

Geofence Warrants by the Numbers People of Internet Research · US 11,554 Google warrants, 2020 Geofence warrants Google received … ~25% Google LE requests, geofence Share of all law enforcement data … 6-3 Chatrie ruling vote Supreme Court majority in Chatrie … 8 Yrs since Carpenter First major digital surveillance r… peopleofinternet.com

Key Takeaways

The Ruling

On June 29, 2026, the Supreme Court held 6-3 in Chatrie v. United States that obtaining location history from Google through a geofence warrant — a court order requiring a tech company to identify every device near a crime scene during a set time window — constitutes a Fourth Amendment search. Justice Elena Kagan, writing for the majority joined by Chief Justice Roberts and Justices Sotomayor, Kavanaugh, and Jackson, held that individuals retain a reasonable expectation of privacy in cell phone location data regardless of how briefly the government surveils their movements, and regardless of the fact that such data is stored with a third party like Google.

The case arose from a May 2019 bank robbery in Midlothian, Virginia. Local police obtained a geofence warrant directing Google to identify every device within a 150-meter radius of a credit union between 4:20 and 5:20 PM on the day of the crime. Through a three-step disclosure process, investigators narrowed nineteen anonymized accounts to three identified individuals, including Okello Chatrie, who was subsequently prosecuted. The district court denied Chatrie's suppression motion by applying the good-faith exception; the Fourth Circuit ultimately split 7-7 on the constitutional question. The Supreme Court granted certiorari to resolve a deepening circuit conflict — the Fifth Circuit had already held geofence warrants "categorically prohibited" by the Fourth Amendment.

Building on Carpenter

Chatrie is the Court's first major digital surveillance ruling since Carpenter v. United States (2018), where a 5-4 majority held that the government must obtain a warrant before accessing seven or more days of historical cell-site location information. Chief Justice Roberts' Carpenter opinion deliberately declined to address shorter surveillance windows, spawning years of divergent lower court rulings and a working assumption in many jurisdictions that brief geofence sweeps were constitutionally unconstrained.

Justice Kagan closed that gap directly. Google's Location History records a device's position approximately every two minutes with twenty-meter precision — a granularity that reveals, as the majority noted, visits to psychiatrists, abortion clinics, gun shows, and political rallies with no temporal minimum required to trigger sensitivity. The opinion rejected any durational threshold, reasoning that line-drawing around time windows would simply invite investigators to exploit whatever period the Court declared safe. The third-party doctrine — the proposition that sharing data with a company forfeits privacy protection — was again set aside as inapt for records that users do not consciously hand over and that Google's own interfaces often obscure.

Justice Gorsuch wrote a notable concurrence arguing that location data is the user's personal property under traditional property-rights theory, an alternative doctrinal path that could command broader agreement in future digital-assets disputes. Justice Jackson concurred separately. Justice Alito, joined in part by Justices Thomas and Barrett, dissented, warning the majority's reasoning "will send seismic waves through our Fourth Amendment doctrine" and arguing the practical impact on Chatrie is nil given Google's subsequent policy changes.

Why Law Enforcement Found Geofence Searches Valuable

Proponents have a genuine case. When investigators hold surveillance footage but lack any suspect identity, a geofence request to Google can narrow an anonymous pool of hundreds of devices to a handful of leads within hours rather than weeks. In high-profile mass-incident investigations, the technique has provided leads where no other method could. Advocates argue it is particularly vital for kidnappings and bombings where every hour matters.

The Supreme Court acknowledged this by refusing to follow the Fifth Circuit's categorical ban. Chatrie does not hold geofence warrants unconstitutional — it holds that executing one is a search that must first clear the Fourth Amendment's probable-cause and particularity requirements before a neutral magistrate. The case was remanded to the Fourth Circuit to assess whether the original 150-meter, sixty-minute warrant met those standards and whether the good-faith exception shields the Chatrie prosecution in any event.

The Proportionate Outcome

Requiring a properly tailored warrant — rather than banning the technique outright — is the proportionate response. What disappears after Chatrie is the ability to conduct pre-warrant dragnet sweeps of thousands of innocent bystanders' location histories simply because they passed near a crime scene. The scale of the practice made judicial oversight unavoidable: Google reported receiving 11,554 geofence warrants in 2020 alone, and by 2021 geofence requests accounted for roughly 25% of all law enforcement data requests to the company. Volume at that level demands more than departmental discretion.

The open internet runs on location-aware services. Every navigation query, food delivery, and rideshare ping is a data point. If this reservoir of intimate behavioral data were freely accessible to investigators without a warrant, the chilling effect on ordinary digital activity would be substantial and asymmetric — falling hardest on people who visit legally protected but socially stigmatized locations. The warrant requirement and the judicial scrutiny it embeds is precisely what keeps that tradeoff workable.

What Chatrie Leaves Open

The ruling's deliberate narrowness leaves significant gaps. The Court explicitly reserved judgment on location data purchased from commercial data brokers, who aggregate and resell device movement records without the legal obligations that apply to companies served with judicial process. Federal agencies have paid brokers for bulk location data specifically to sidestep warrant requirements — a practice Chatrie does not reach.

The ruling also predates the full effect of Google's December 2023 shift of Location History from its centralized Sensorvault database to encrypted, device-level storage. With data on users' phones rather than Google's servers, geofence warrants directed at the company become technically hollow. Law enforcement will increasingly turn to other data holders — Apple, Meta, Snapchat, telecommunications carriers — and the constitutional framework for those demands remains undeveloped at every circuit.

The Larger Arc

Chatrie extends a line of decisions — Jones (2012), Riley (2014), Carpenter (2018) — in which the Court has consistently refused to let surveillance technology outrun Fourth Amendment protection. Each ruling has been incremental and contested. None has been premature. The alternative — allowing the third-party doctrine to swallow all digital records generated by the devices Americans carry everywhere — would effectively delete the Fourth Amendment in the connected age. Warranted, narrowly tailored geofence searches are compatible with effective policing. Warrant-free mass sweeps of innocent people's location histories are not. Chatrie draws that line in the right place.

Sources & Citations

  1. Chatrie v. United States — LII/Cornell
  2. Carpenter v. United States — LII/Cornell
  3. EFF: Victory — Constitution Protects Location Data
  4. SCOTUSblog: Court rules geofence warrant was a search
  5. Just Security: Unpacking the Chatrie Decision
  6. Wikipedia: Geofence Warrant — statistics