Do Geofence Warrants Violate Art. 1 Sec. 7 of the Washington Constitution?

By Judge Michael Schwartz.  

One of law enforcement’s latest tools in the fight against crime is the “geofence” warrant. Unlike traditional warrants that identify a suspect in advance of a search, a geofence warrant essentially allows the police to work backward, gathering data to identify electronic devices at or near the scene of a crime during a specified time period. By identifying all (or most) of the electronic devices, further requests lead to the account holder for those devices, and (hopefully) a suspect. This law enforcement tool presents some novel constitutional issues.

To understand geofence warrants, one must first understand what data the government is seeking, where it is stored and how it got there. When a person uses an Android device, and “opts in” to utilize Google’s location service (such as Google Maps), that device’s location is constantly recorded and stored in Google’s enormous database called  Sensorvault. The business of tracking a cellphone user’s location is a major reason Google earns such large advertising revenues. The location data allows Google to tailor ads to people based on where they are. What you eat, read and watch is just some of the data Google captures. But for law enforcement’s purposes, it is the location data, recorded at specific times, that underscores the rapid rise in the application for geofence warrants.

In a hypothetical scenario, the police are called to a robbery of a convenience store. The police are told the suspect fled on foot in a particular direction. Police view the in-store surveillance video, which is grainy at best, and because the suspect is wearing a mask, a solid identification by the clerk is unlikely. Further crime scene analysis fails to turn up any fingerprints, DNA or other usable forensic evidence. The police have hit a roadblock. Thus, they seek a search warrant from Google for all data that reflects any Android devices within a prescribed area of the robbery (the geofence) during a window of time from Google’s database. After conducting a search of the Sensorvault database, Google responds with location information of all the devices using the Google app that were present within the prescribed area during the prescribed period of time.

The police at this point have only each device’s identifier, not who it belongs to. In order to gather that information, the police must narrow the field and look for a device (or devices) that was in the store at the time of the robbery as well as any devices that followed the path the robber fled. Armed with this information, the police seek a second warrant, asking that Google produce information about the subscriber for each account linked to a device within the geofence. Once Google supplies that information, further investigation may lead them to a particular suspect for which probable cause exists for that person’s arrest for armed robbery.

Remember that in the U.S. Supreme Court’s decision in United States v. Carpenter, the Court ruled that the Third Party Doctrine does not apply to cell phone location data. The Third Party Doctrine stems from U.S. v. Miller, in which the Supreme Court ruled that information that you voluntarily give to others, such as bank records or dialed phone numbers, do not carry a reasonable expectation of privacy under the 4th Amendment to the U.S. Constitution. Instead, they ruled that location data, or the privacy in a person’s physical movements, must be strongly protected. The decision did not overrule the Third Party Doctrine, and it did not suggest the exception to it granted in Carpenter would extend more broadly. The Court called our cell phone location data “unique” in this regard.

But also remember that our state Supreme Court has repeatedly found that Washington Constitution, Art I, sec. 7 is qualitatively different from the Fourth Amendment and provides greater protections. Article I, section 7 “is grounded in a broad right to privacy” and protects citizens from governmental intrusion into their private affairs without the authority of law. State v. Chacon Arreola, 176 Wash.2d 284, 291, 290 P.3d 983 (2012). Under article I, section 7, a search occurs when the government disturbs “those privacy interests which citizens of this state have held, and should be entitled to hold, safe from governmental trespass absent a warrant.” State v. Myrick, 102 Wash.2d 506, 511, 688 P.2d 151 (1984). Indeed, the Washington Supreme Court has specifically found that individuals have a constitutional privacy right in their cell phone location data. State v. Muhammad, 194 Wash.2d 577, 584, 451 P.3d 1060 (2019).

Currently, there are no appellate court decisions in Washington determining the validity of geofence warrants. In a federal court in Chicago, two federal magistrate judges have ruled that applications for geofence warrants there were unconstitutional under the Fourth Amendment. See, In the Matter of Search of Information Stored at Premises Controlled by Google, Case No. 20 M 297 (USDC for Northern Ill., E. Div., 2020). The court found that the application there had two Constitutional infirmities: 1) overbreadth and 2) lacking particularity. While prosecutors have argued that they tailor geofence warrants as narrowly as possible, privacy advocates assert that the warrants inherently sweep up innocent people in the data dragnet.

In at least one instance, Geofence data ensnared a man who seemed to be at the site of a 2018 killing in Avondale, Arizona. Jorge Molina spent six days in jail before his lawyer provided police with evidence exonerating him. His mother’s ex-boyfriend was later arrested in the killing. It turns out Molina had given the man his old cellphone, which was still logged in to his Google account.

As technology advances, lawyers and judges will be called upon to struggle with newfound capabilities in data collection. Society’s privacy concerns will continue to be weighed against the government’s interest in public safety and criminal investigations.


Judge Michael Schwartz was appointed to the Pierce County Superior Court in 2015. Prior to taking the bench he practiced mainly criminal defense in both State and Federal courts. He is an instructor at the Washington State Judicial College, teaching search warrants to Judges and Commissioners.
Judge Michael Schwartz (253) 798-7576.