The police told the suspect, Jorge Molina, they had data tracking his phone to the site where a man was shot nine months earlier. They had made the discovery after obtaining a search warrant that required Google to provide information on all devices it recorded near the killing, potentially capturing the whereabouts of anyone in the area.
Investigators also had other circumstantial evidence, including security video of someone firing a gun from a white Honda Civic, the same model that Molina owned, though they could not see the license plate or attacker.
But after he spent nearly a week in jail, the case against Molina fell apart as investigators learned new information and released him. Last month, the police arrested another man: his mother’s ex-boyfriend, who had sometimes used Molina’s car.
The warrants, which draw on an enormous Google database employees call Sensorvault, turn the business of tracking cellphone users’ locations into a digital dragnet for law enforcement. In an era of ubiquitous data gathering by tech companies, it is just the latest example of how personal information — where you go, who your friends are, what you read, eat and watch, and when you do it — is being used for purposes many people never expected. As privacy concerns have mounted among consumers, policymakers and regulators, tech companies have come under intensifying scrutiny over their data collection practices.
The Arizona case demonstrates the promise and perils of the new investigative technique, whose use has risen sharply in the past six months, according to Google employees familiar with the requests. It can help solve crimes. But it can also snare innocent people.
Technology companies have for years responded to court orders for specific users’ information. The new warrants go further, suggesting possible suspects and witnesses in the absence of other clues. Often, Google employees said, the company responds to a single warrant with location information on dozens or hundreds of devices.
Law enforcement officials described the method as exciting, but cautioned that it was just one tool.
“It doesn’t pop out the answer like a ticker tape, saying this guy’s guilty,” said Gary Ernsdorff, a senior prosecutor in Washington state who has worked on several cases involving these warrants. Potential suspects must still be fully investigated, he added. “We’re not going to charge anybody just because Google said they were there.”
It is unclear how often these search requests have led to arrests or convictions, because many of the investigations are still open and judges frequently seal the warrants. The practice was first used by federal agents in 2016, according to Google employees, and first publicly reported last year in North Carolina. It has since spread to local departments across the country, including in California, Florida, Minnesota and Washington. This year, one Google employee said, the company received as many as 180 requests in one week. Google declined to confirm precise numbers.
The technique illustrates a phenomenon privacy advocates have long referred to as the “if you build it, they will come” principle — anytime a technology company creates a system that could be used in surveillance, law enforcement inevitably comes knocking. Sensorvault, according to Google employees, includes detailed location records involving at least hundreds of millions of devices worldwide and dating back nearly a decade.
The new orders, sometimes called “geofence” warrants, specify an area and a time period, and Google gathers information from Sensorvault about the devices that were there. It labels them with anonymous ID numbers, and detectives look at locations and movement patterns to see if any appear relevant to the crime. Once they narrow the field to a few devices they think belong to suspects or witnesses, Google reveals the users’ names and other information.
‘‘There are privacy concerns that we all have with our phones being tracked — and when those kinds of issues are relevant in a criminal case, that should give everybody serious pause,” said Catherine Turner, a Minnesota defense lawyer who is handling a case involving the technique.
Investigators who spoke with The New York Times said they had not sent geofence warrants to companies other than Google, and Apple said it did not have the ability to perform those searches. Google would not provide details on Sensorvault, but Aaron Edens, an intelligence analyst with the sheriff’s office in San Mateo County, California, who has examined data from hundreds of phones, said most Android devices and some iPhones he had seen had this data available from Google.
In a statement, Richard Salgado, Google’s director of law enforcement and information security, said that the company tried to “vigorously protect the privacy of our users while supporting the important work of law enforcement.” He added that it handed over identifying information only “where legally required.”
Molina, 24, said he was shocked when the police told him they suspected him of murder, and he was surprised at their ability to arrest him based largely on data.
“I just kept thinking, You’re innocent, so you’re going to get out,” he said, but he added that he worried that it could take months or years to be exonerated. “I was scared,” he said.
While Molina was in jail, a friend told his public defender, Jack Litwak, that she was with him at his home about the time of the shooting, and she and others provided texts and Uber receipts to bolster his case.
Months after his release, Molina was having trouble getting back on his feet. After being arrested at work, a Macy’s warehouse, he lost his job. His car was impounded for investigation and then repossessed.
The investigators “had good intentions” in using the technique, Litwak said. But, he added, “they’re hyping it up to be this new DNA type of forensic evidence, and it’s just not.”
This article originally appeared in The New York Times.