SurveillancePolice cell-phone tracking raises privacy concerns

Stingray device allows police to track cell phones' location // Source: duke.edu

Law enforcement agencies around the country are using the International Mobile Subscriber Identity locator (IMSI catcher), known as Stingray, to track cellphone users for the purpose of assisting criminal investigations. A  Stingray masquerades as a cellphone tower, to which cellphones send signals every seven to fifteen seconds whether a phone call is active or not, tricking phones into sending a signal that law enforcement can later use to identify the serial number of the phone and track the subscriber or cellphone user.

Detective Sy Ray of Gilbert, Arizona is a trained expert who teaches a class on the Stingray. Ray recounts a story when a Stingray helped law enforcement capture a wanted criminal. According to Arizona Central, a Yuma woman and her children were kidnapped from a safe house in October 2013. Her estranged husband sexually assaulted her and fled with their children, leaving the woman behind at a motel. The estranged husband was using his cellphone to call the woman, threatening to kill the children and himself. Police, using Stingray technology, tracked the husband and the children to the Globe/Miami area, and he surrendered without incident.

“If that were your kids or your grandkids, you would expect that kind of service,” Ray said. “To me, it’s a disservice if we don’t do that.”

Privacy advocates are worried about widespread police tracking of cellphones and violations of public privacy. Ray says that the Stingray is used by police only in life threatening situations such as the Yuma case. “When we turn on the equipment, I feel there is an expectation that most of our residents would agree with using it,” Ray said. “A family or a loved one is in a dire situation and we need to get someone off the street. There’s a potential loss of life.” 

Ray told AZCentral that in the Yuma case, the police tracked the estranged husband’s cellphone through the provider after obtaining an emergency 48-hour order from the phone carrier. When that special pass expires, detectives need to get a search warrant to continue tracing the phone.

Most of the time, police are filing search warrants to obtain the serial number of a suspect’s phone.

“If the general public saw the hoops we jump through in a criminal situation, they would be amazed,” Ray said. “There are tons of checks and balances that people don’t know about.” Sergeant Tony Landato, a Mesa police spokesman, considers the device an investigative technique used in real time to save lives. Stingray can also be used in long-term investigations such as homicides to develop a timeline by connecting the movements of a suspect. According to Ray, while privacy concerns are valid because Stingray picks up serial numbers of all phones in the area in which it is being used, law enforcement officers do not tend to record irrelevant series numbers that have nothing to do with the case.

He also notes that with Stingray, law enforcement units do not have access to text messages, voice mail, or other communication content. “It’s only a location device,” Ray said. “It’s not an interception device. We can’t intercept content at all.”