What the Minnesota Supreme Court's Geofence Warrant Ruling Actually Means

What Is a Geofence Warrant?

A geofence warrant is a search warrant that orders a technology company — usually Google — to hand over data identifying every device that was inside a defined geographic area during a defined window of time. Instead of starting with a suspect and asking where they were, police start with a place and a time and ask who was there. Google pulls the answer from the enormous store of location data it collects from phones running its services.

The investigative process generally runs in three steps: police get an anonymized list of device IDs in the area, then ask for expanded location data on the devices that look relevant, then seek subscriber information (the name and account details) for the device they want to identify.

What Happened in State v. Contreras-Sanchez

The case grew out of a homicide investigation. A man was reported missing, and his body was later found in a drainage culvert in Castle Rock Township. Investigators applied for a geofence warrant directing Google to provide location data for devices within a defined area near where the body was found, covering the period from the victim's disappearance to the discovery of his body.

That data led police to a device, then to surveillance footage, then to a second warrant for the subscriber information tied to the phone. The data connected Ivan Contreras-Sanchez to the crime, and he later made admissions during police questioning. He was convicted of second-degree intentional murder. The district court denied his motion to suppress the geofence evidence, and the Court of Appeals affirmed. The Minnesota Supreme Court then took the case to decide the constitutional question.

What the Court Actually Held

The decision has several distinct parts, and the distinctions matter:

• Location data is protected. The Court held that people have a reasonable expectation of privacy in the location data Google stores about them. Accessing that data is a search under the Minnesota Constitution, so police need a warrant to get it.
• Geofence warrants are not banned. The Court declined to hold that geofence warrants are categorically unconstitutional "general warrants." They can be valid if written correctly.
• This warrant had probable cause. The Court agreed there was a fair probability the search would turn up evidence — so the problem was not a lack of probable cause.
• The warrant failed on particularity. This is the heart of the ruling. The warrant let police decide, on their own, which devices inside the geofence to subject to an expanded search — and it allowed location tracking outside the geofence boundaries with no real limit. The Court described this as giving officers unchecked discretion that amounted to impermissible exploratory rummaging through location data.

Because the warrant lacked the required particularity, the Court reversed and sent the case back to the Court of Appeals to address issues it had not previously reached.

Why "Particularity" Is the Key Word

Both the U.S. and Minnesota Constitutions require that a warrant particularly describe the place to be searched and the things to be seized. The point is to prevent open-ended searches where police, rather than a neutral judge, decide how far to go once they are inside. The Court's concern was not that police looked for data near a crime scene — it was that the warrant set no meaningful limit on how that search could expand, leaving officers free to treat any device in the area as a suspect's and to follow devices beyond the geofence.

What the Ruling Does Not Mean

It is easy to over-read a headline. The decision does not say:

• that geofence warrants are illegal in Minnesota;
• that police can never obtain Google location data;
• that every past conviction involving location data is now void; or
• that the defendant here automatically goes free — the case was sent back for further proceedings, including issues the lower court never decided.

Why This Matters for a Criminal Case Today

Location data now appears in many kinds of cases — not just homicides, but burglaries, robberies, drug investigations, and more. After this ruling, the way a geofence warrant was written and executed is a live issue worth scrutinizing. The questions a defense lawyer will ask include: Was the geographic area drawn narrowly? Was the time window tight? Did the warrant limit how the search could expand, or did it leave that to the officers? Was data collected outside the geofence? Each of those can be the basis of a motion to suppress.

Minnesota has also shown, in this decision, that it will sometimes read its own constitution as more protective than the Fourth Amendment — which means state-law arguments can matter independently of federal law.

Key Terms

• Geofence warrant: A warrant ordering a company to identify devices present in a set area during a set time.
• Particularity: The constitutional requirement that a warrant precisely describe what may be searched and seized, limiting police discretion.
• Probable cause: A fair probability that a search will produce evidence of a crime.
• Reasonable expectation of privacy: The standard that determines whether government access to information counts as a "search."
• Motion to suppress: A request to exclude evidence obtained through an unconstitutional search.