Supreme Court Holds That Geofence Warrants Trigger Fourth Amendment Protections

A major victory for digital privacy and an important reminder that constitutional rights evolve alongside technology.

Today, the United States Supreme Court issued one of the most important Fourth Amendment decisions in recent years, holding in Chatrie v. United States that law enforcement conducts a Fourth Amendment search when it obtains a person’s historical location data from Google through a geofence warrant.

The decision recognizes something that has become increasingly obvious in modern life: our cell phones reveal an extraordinarily detailed picture of who we are, how we live, and where we go.

What is a geofence warrant?

Unlike a traditional search warrant, police using a geofence warrant often do not begin with a suspect.

Instead, investigators draw a virtual boundary—a “geofence”—around the location of a crime and require a technology company, most commonly Google, to identify every device that was present within that area during a specified period of time.

The investigation then works backwards.

After reviewing anonymous location data, law enforcement narrows the list before eventually requesting identifying information for selected users.

The practical effect is that everyone who happened to be in the area becomes part of the investigation, regardless of whether they had anything to do with the crime.

What did the Supreme Court decide?

Writing for the majority, Justice Elena Kagan held that individuals have a reasonable expectation of privacy in their historical cell phone location information, even when that information is stored by a third-party technology company.

The Court relied heavily on its landmark decision in Carpenter v. United States, explaining that modern location history is even more revealing than traditional cell-site location information. Google’s Location History can pinpoint a user’s location within approximately 20 meters, record movements every few minutes, and even identify what floor of a building someone occupies.

The Court rejected the government’s argument that people lose their privacy simply because Google stores the information. Using modern smartphone services does not mean Americans have surrendered their constitutional protections.

What the Court did not decide

Although the Court concluded that obtaining Google’s location history constitutes a Fourth Amendment search, it stopped short of deciding whether the particular geofence warrant used in this case was constitutional.

Instead, the Court sent the case back to the Fourth Circuit to determine whether the warrant satisfied the Fourth Amendment’s traditional requirements of:

• Probable cause
• Particularity
• Reasonableness

Those questions remain open and will likely generate significant litigation in courts across the country.

Why this matters

For years, geofence warrants have raised serious constitutional concerns because they invert the traditional investigative process.

Rather than identifying a suspect and then seeking evidence, police first identify everyone who happened to be near a crime scene and then work to determine who might become a suspect.

The Supreme Court’s decision acknowledges that this type of broad digital surveillance implicates core Fourth Amendment protections.

As technology becomes increasingly woven into everyday life, courts must continue to ensure that constitutional rights keep pace.

What this means for criminal cases

This decision is likely to affect both pending and future criminal investigations involving:

• Geofence warrants
• Historical location data
• Google account records
• Digital tracking technologies
• Other forms of location-based surveillance

Defense attorneys should carefully evaluate whether law enforcement properly obtained digital location evidence and whether warrants satisfy the constitutional requirements emphasized by the Supreme Court.

As digital evidence becomes more common in criminal prosecutions, Fourth Amendment litigation will continue to shape the limits of government surveillance.

Birdsall Muller LLC

At Birdsall Muller LLC, we closely monitor developments in constitutional law because decisions made today often become trial issues tomorrow. We aggressively challenge unlawful searches, unlawful seizures, and unconstitutional government conduct, whether the evidence comes from a physical search or sophisticated digital surveillance.

If you are facing criminal charges involving electronic evidence, location tracking, or search warrant issues, experienced legal counsel can make all the difference.