On April 15, 2026, the Minnesota Supreme Court issued a major decision addressing the constitutionality of geofence warrants—a rapidly expanding law enforcement tool that collects location data from tech companies like Google. In State v. Contreras-Sanchez, the court struck a careful balance: allowing the use of geofence warrants in principle, but imposing meaningful constitutional limits on how they are used.
What Is a Geofence Warrant?
A geofence warrant allows police to request data from companies like Google identifying all devices that were within a defined geographic area during a specified time period. This can include dozens—or even hundreds—of people, most of whom are not suspects.
In this case, investigators used a geofence warrant to identify a suspect in a homicide after a body was found in a rural culvert. The warrant ultimately led police to Ivan Contreras-Sanchez, who was convicted of murder.
The Big Question: Are These Warrants Constitutional?
The Minnesota Supreme Court addressed this issue for the first time and reached four key conclusions.
1. Location Data Is Protected by the Constitution
The court held that people have a reasonable expectation of privacy in their cell phone location data stored by Google. Accessing that data is therefore a “search” under the Minnesota Constitution, meaning police generally need a warrant.
The court emphasized how revealing this data can be—potentially exposing a person’s movements, relationships, and private activities, from medical visits to religious or political affiliations.
2. Geofence Warrants Are Not Automatically Illegal
Importantly, the court rejected the argument that all geofence warrants are unconstitutional “general warrants.”
Instead, the court held that these warrants can be valid, especially when they are narrowly tailored in time and location.
3. This Warrant Had Probable Cause
The court found that the warrant in this case met the probable cause requirement, meaning there was a fair probability that evidence of the crime would be found in Google’s data.
Notably, the court rejected the argument that police must show probable cause for every individual within the geofence.
4. But the Warrant Failed the “Particularity” Requirement
This is where the warrant ultimately failed.
The court held that the warrant was not sufficiently “particular” because it gave law enforcement too much discretionto decide which devices to investigate further—without additional judicial oversight.
Specifically, after obtaining anonymized data, officers could decide on their own which devices were “relevant” and then obtain more detailed location data—without going back to a judge. The court found this amounted to unconstitutional “exploratory rummaging.”
The Result: Conviction Reversed (For Now)
Because the warrant violated the Minnesota Constitution, the court reversed the lower court’s decision and sent the case back for further proceedings.
The lower court will now consider unresolved issues like whether the good-faith exception applies or whether the error was harmless.
Why This Decision Matters
This ruling is one of the most significant state-level decisions on digital privacy in recent years. It does three important things:
- Expands privacy protections under the Minnesota Constitution beyond federal law in some respects
- Allows modern investigative tools like geofence warrants—but with limits
- Signals that courts will scrutinize how data is analyzed, not just how it is collected
The Bigger Picture
The decision comes at a time when courts across the country are grappling with how traditional Fourth Amendment principles apply to modern surveillance technologies.
The U.S. Supreme Court is expected to weigh in soon on similar issues, meaning this area of law is still evolving rapidly.
Bottom Line
The Minnesota Supreme Court didn’t ban geofence warrants—but it made clear they are not a blank check. Courts must ensure that digital searches are tightly controlled and subject to meaningful judicial oversight.
For law enforcement, the message is clear: get a warrant—and make it precise.
I’d especially like to thank all of the people and organizations who put countless hours into getting this matter reversed including the Office of the Minnesota Public Defender, ACLU, MACDL (Minnesota Association of Criminal Defense Lawyers), and the Electronic Frontier Foundation.
