Judge reprimands the use of a cellphone dragnet to locate a suspect in bank robbery.

Geofence warrants could be ruled illegal by a federal judge. This could limit the use of surveillance tools that are based on Google location data.

Judge reprimands the use of a cellphone dragnet to locate a suspect in bank robbery.

A federal judge ruled that Virginia authorities violated the Constitution by using Google location data to locate people near the scene in a bank robbery.

This policing tactic is used widely across the country and was found to be in violation of the Fourth Amendment's protections from unreasonable searches. It involves obtaining information on innocent persons without any evidence that they could be suspects.

The decision issued by Judge M. Hannah Lauck of U.S. District Court Eastern District of Virginia on Thursday could make it harder for police to use geofence orders. These warrants draw on cellphone tracking data to locate people close to a crime scene. Law enforcement officers have found the warrants useful in situations where traditional investigation methods have failed to provide enough leads. These warrants can be used to solve crimes such as burglaries, home invasions, murders, and sexual assaults. They also help to identify who stormed U.S. Capitol in January 2021.

Privacy advocates and defense lawyers are concerned about the secret collection of data by the government from dozens to hundreds of people. Most of these individuals have nothing to do a crime. Critics argue that warrants can lead to innocent people being wrongfully arrested. This happened to a Florida resident who was caught up in a 2019 investigation into burglary. He had been riding past the scene.

Albert Fox Cahn is the executive director of Surveillance Technology Oversight Project. This civil rights non-profit opposes geofence warrants and said that Lauck had issued a landmark ruling that could result in more courts rejecting requests for Google location data.

Cahn stated, "This will be a wake up call for judges who have been rubber stamping these kinds of warrants at both the federal and the state levels."

Geofence warrants can be legalized by law enforcement because Google users have agreed to their location being tracked. Police say that they only receive anonymized data from Google until they discover a device that raises suspicion. Police say that the evidence of a geofence warrant is not sufficient to prove someone guilty of a crime.

After three weeks of trying unsuccessfully to identify a gunman, a Chesterfield County Police Department detective sought a geofence warrant. The warrant was issued after a worker had to open a safe, and the suspect walked out with $195,000. The surveillance footage revealed that the suspect was carrying a cellphone to his ears when he arrived at the bank. The detective asked for a warrant to Google for the location data of all cellphones within a 150-meter radius (about 164 yards) of the bank during this heist. The warrant was approved by a local magistrate.

Google provided location data for 19 devices, but no identifying information. After narrowing down the list to three devices in the area, the detective requested information from Google about the names of the people associated with them. Investigators were led to Okello Chatrie (27 ), who was arrested for armed robbery in September 2019. Chatrie, who has pleaded guilty to the charge but has been held in jail ever since.

His lawyers, which included Michael Price, lead litigator of National Association of Criminal Defense Lawyers Fourth Amendment Center, argued the geofence warrant was in violation of the Constitution and that any information that police gleaned from it should be rejected.

Laura Koenig (public defender for Price and Chatrie), declined to comment on Lauck’s decision. The Eastern District U.S. Attorney's Office and Chesterfield County Commonwealth's Attorney's Office also declined to comment on Lauck's ruling. Google did not respond. The magistrate who granted the warrant was not available for comment as well as the detective who requested it were unavailable.

Chatrie's challenge led to the most thorough courtroom examination of geofence warrants, including hearings that examined the details of Google data and how law enforcement negotiates for this information with Google. Investigators also had to make use of it.

The number of geofence warrants that police have submitted to Google has increased dramatically. According to the latest data, Google received 982 geofence orders from law enforcement in 2018. In 2020, that number will rise to 11,554,. Google now has geofence warrants issued by agencies in all 50 US states, Washington D.C. and the federal government.

Geofence warrants have been largely uncontested by U.S. courts until now. There are rare exceptions to this rule. These include two Illinois federal magistrates who denied requests for 2020 geofence warrants, a Kansas federal magistrate who turned down a request in last year, and a Fairfax judge who denied a warrant request in last month.

The Chatrie case was one of the first to examine all aspects of geofence warrants. It included testimony from Google executives and experts as well as arguments and experts from Chatrie and the government. This process took more than two years.

Lauck ultimately sided with Chatrie, but with a catch.

Lauck stated in her March 3 decision, that authorities' use of the geofence warrant to capture data on large numbers of people in an area that contained a church and a restaurant with little judicial oversight "plainly violates" the Fourth Amendment rights. Lauck pointed out that the warrant "swept into unrestricted position data for private citizens who did not have any reason to be under Government scrutiny." This included one person who didn’t appear to be within the 150-meter area.

Chatrie's expert testified that he was able to identify the probable identities of three individuals whose location data was requested in response to the warrant. He identified their likely homes, tax records, and social media accounts.

Lauck did not invalidate the evidence obtained by the warrant. This could have made it more difficult to prosecute Chatrie. Lauck instead ruled that the evidence in this case could be accepted. He said that the detective who sought the warrant wasn't at fault as he didn't have anyone telling him it was invalid. Lauck also stated that he had previously obtained geofence warrants and had spoken with prosecutors. Chatrie will not be able to benefit from Lauck’s ruling. He is currently awaiting trial.

Chatrie can still be tried using evidence from the geofence warrant. However, Lauck's ruling could make obtaining warrants more difficult for police in the future and increase the likelihood that judges will suppress evidence from them. Experts agree.

Jennifer Lynch, the Electronic Frontier Foundation's surveillance ligation director, stated that she believes other courts will take Lauck's view into account when deciding whether or not to approve geofence warrants.

Lynch stated that there are increasing numbers of warrant requests and judges are beginning to pay more attention to them. Lynch agreed.

Jake Laperruque is senior policy counsel at The Constitution Project, Project on Government Oversight. He said that Lauck's ruling might make it easier for defendants not only to challenge geofence warrants, but also other types of mass surveillance tools.

Lauck stated that Lauck had "made it quite clear that this type dragnet measure on it's face without proactive efforts at limiting it is unacceptable." Laperruque agreed.

Lauck explained that her decision was part the judiciary’s ongoing efforts to apply the tenets of the Fourth Amendment to previously impossible investigatory methods. This is made possible by the huge amount of location data that Google and other tech giants have collected.

She stressed that her ruling did not mean that geofence warrants could be used. She suggested there may be a way around the Fourth Amendment. Perhaps by limiting the scope of the warrants or by getting more input from the court. She cited an example from Washington, D.C., where a federal court required law enforcement to seek additional court approval in December before obtaining personal information related to devices that belonged likely suspects.

The judge concluded that lawmakers should address the future of geofence warrants. She pointed out that there is no law that prohibits tech companies collecting large amounts of customer data. She cited New York's bill that would ban geofence warrants.

Lauck wrote that "thoughtful legislation could not just protect the privacy of citizens but also could ease the burden on companies to police law enforcement request for the data they have."