Supreme Court Brings Geofence Warrants Under Fourth Amendment
The Supreme Court handed down a major Fourth Amendment decision Monday, ruling that police conduct a constitutional search when they obtain a person’s Google Location History data through a geofence warrant.
A geofence warrant works backward. Instead of asking for records about a known suspect, police draw a virtual boundary around a crime scene and ask a tech company which devices appeared inside it during a specific time window. The practice did not arise from a clear federal statute written for this technology. It grew out of ordinary warrant law, electronic-records procedures, and company compliance protocols.
That is the significance of Chatrie v. United States. The decision says the government cannot avoid the Fourth Amendment simply because the data sits on a tech company’s servers.
The Robbery and the Warrant
The case began with a 2019 credit-union robbery in Midlothian, Virginia.
Police knew where and when the crime happened. They did not know who committed it. Witnesses and surveillance footage showed that the robber approached the credit union from near a church and appeared to speak on a cellphone.
So, officers sought a geofence warrant directed at Google. That warrant covered a 150-meter radius around the credit union. It also used a three-step process.
First,
Google would produce anonymized location data for all cell phones within the geofence 30 minutes before to 30 minutes after the robbery[.]
Second, officers narrowed the list and received more anonymized data for some devices over a two-hour window, “both inside and outside the geofence.”
Third, officers narrowed the list again, and Google gave them identifying information, “including names and phone numbers.”
Google ultimately gave police three names. One belonged to Okello Chatrie. Prosecutors later charged him with robbery and firearms offenses.
Chatrie moved to suppress the Google data. He argued that police had searched him under the Fourth Amendment and that the warrant did not satisfy constitutional standards.
The lower courts divided. The district court said the warrant “plainly” violated the Fourth Amendment, but allowed the evidence under the good faith exception. A Fourth Circuit panel then held that no search had occurred because Chatrie had exposed the data to Google. The full Fourth Circuit split evenly.
The Supreme Court took the case.
The Ruling
Justice Elena Kagan wrote the Court’s opinion. Chief Justice John Roberts and Justices Sonia Sotomayor, Brett Kavanaugh, and Ketanji Brown Jackson joined it.
The holding was narrow, but powerful.
The Court ruled that police conducted a Fourth Amendment search when they acquired Chatrie’s Google Location History data. The reason was simple:
An individual has a reasonable expectation of privacy in records about his cell phone’s location, and police intrude on that constitutionally protected interest when they demand the information — even though for only a limited time, and from a third-party tech company.
The Court did not decide whether this particular warrant was valid. It sent that question back to the Fourth Circuit. The appeals court must now decide whether each step of the warrant met the Fourth Amendment’s requirements of probable cause and particularity.
That distinction matters.
The ruling does not say police can never use geofence warrants. It says they cannot pretend that a geofence demand is something less than a search. And so, the Constitution applies at the front door.
Location History
The government leaned heavily on the idea that Chatrie had shared his location information with Google. That argument invokes the so-called third-party doctrine.
Under that doctrine, people often lose privacy claims regarding information they voluntarily give to banks, phone companies, or other businesses. The government argued that Google Location History should fall into that bucket.
The Court rejected that view.
It relied on Carpenter v. United States, the 2018 case involving historical location records from a wireless carrier:
Carpenter is the most recent decision of this Court to consider the Fourth Amendment’s application to new surveillance technologies — indeed, to law enforcement’s use of those technologies to create a “chronicle of [a cellphone] user’s past movements.”
There, the Court held that police generally need a warrant to obtain cellphone location data because it can reveal a detailed map of a person’s movements.
Chatrie applied that same principle to Google Location History, but found the privacy concern even stronger. That is because Google’s data can be more precise, more frequent, and more revealing than the cell site records at issue in Carpenter.
The Court also noted that users often treat Location History as their own record. They may use it to remember where they ate, where they traveled, or what route they took:
The records thus serve as a personal journal of a user’s movements, which that user consults (and even can edit) for his own purposes.
It resembles email, photos, calendars, and documents stored in the cloud. The court concluded,
And as a result, that he reasonably expects to be shielded from the “inquisitive eyes” of the government.
Revealing Two Hours
The government also argued that this case involved only a short window of data. Police obtained about two hours of Location History. In the government’s view, that was too little to “bring the Fourth Amendment into play.” Officers, it suggested, should get some “Fourth Amendment grace period” when reviewing location data.
The Court rejected that argument, too.
Two hours may reveal little. But it may also reveal a great deal. Some trips are “indisputably private,” such as doctor’s visits. At the same time,
A cell phone … “faithfully follows” him not only through “public thoroughfares [but] into private residences, doctor’s offices, political headquarters, and other potentially revealing locales.”
It adds,
Location History — even two hours of it — allows officers to target one-off events of potential interest: a gun show, say, or a political rally.
That is the point. The Fourth Amendment does not activate only after the government collects enough information to build a full profile. It applies when the government invades a protected privacy interest.
Nor does a search become harmless because the government selects only a short slice from a much larger database. The deeper concern, the Court explained, is that
the government can access all of a cell-phone user’s movements, in both public and private places — that it possesses a virtual panopticon with which to scrutinize its citizens’ activities.
Old-fashioned police work started with a suspect and built toward evidence. Geofence warrants can start with a place and generate suspects from a crowd. That does not make them useless. It makes them dangerous if courts do not enforce the constitutional boundaries.
The Dissent
Justice Samuel Alito dissented, joined in part by Justices Clarence Thomas and Amy Coney Barrett (she also wrote separately).
The dissent took a more limited view of the Fourth Amendment. It argued that the police did not search Chatrie in the constitutional sense because they obtained only a limited amount of data, covering a short period, and because the movements at issue occurred largely in public. It also leaned on the older third-party doctrine, which treats some information shared with a company as less protected from government access.
In the dissent’s view, Google Location History looked less like a private diary and more like business records held by a third party. The dissent also worried that the majority extended Carpenter too far, turning a limited rule about longer-term cell-site tracking into a broader shield for digital location records.
That view, of course, would give the government too much room in the digital age.
The majority understood that technology changes the practical meaning of government power. And the easier it becomes to reconstruct private life from digital records, the more important it becomes for the Fourth Amendment to stand in the way.
