While the number of people who have heard of Sensorvault is likely limited, its applications in law enforcement circles could change that relatively quickly.
Sensorvault is an enormous Google database that records cellphone users’ locations. Tech savvy law enforcement agencies have come to see Sensorvault as a means to help solve robberies, sexual assaults, arsons and murders.
Google employees told The New York Times that Sensorvault includes detailed location records involving hundreds of millions of devices worldwide and dating back nearly a decade.
As an example of the technology’s use, The Times reported on a murder in a Phoenix suburb. Police told the suspect, Jorge Molina, they had data tracking his phone to the site where a man was shot nine months earlier as well as other circumstantial evidence.
Police 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 — suspects or witnesses — in the area.
After Molina spent nearly a week in jail, the case against him fell apart as investigators gathered additional information.
According to The Times report, technology companies have for years responded to court orders for specific users’ information. But the new warrants go further, suggesting possible suspect and witnesses in the absence of other clues. Google employees told The Times, the company often responds to a single warrant with location information on dozens or hundreds of devices.
It’s unclear how often these search requests have led to arrests or convictions as many of the investigations are still open and judges frequently seal the warrants.
The practice was first used by federal agents in 2016, Google employees told The Times, and first publicly reported last year in North Carolina. It has since spread to local departments, including in California, Florida, Minnesota and Washington.
The new court 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 after which 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 possible suspects or witnesses, Google reveals the users’ names and other information.
Richard Salgado, Google’s director of law enforcement and information security, told The Times the company tried to “vigorously protect the privacy of our users while supporting the important work of law enforcement.” He added that the company handed over identifying information only “where legally required.”
Orin Kerr, a law professor at the University of Southern California and an expert on criminal law in the digital age, told The Times the searches raise constitutional questions as the Fourth Amendment says a warrant must request a limited search and establish probable cause that evidence related to a crime will be found.
Jack Litwak, the public defender assigned to Jorge Molina’s case, said some investigators are hyping the Sensorvault information as new DNA-type of forensic evidence. That is, in our view, an apples and oranges comparison.
The Supreme Court has yet to rule on anything like geofence searches, but it likely will at some point in the future. Given the obvious privacy concerns, that ruling will hopefully come sooner rather than later.