In search for Fla. woman, satellite blazed trail
The GPS in Susan Fast's Lexus kept a record of where the vehicle went
Along with cell phones, GPS systems have become a key tool for law enforcement in recent years, allowing detectives to retroactively trace the movements of suspects or to find victims.
But it is a development that worries civil liberties advocates, who say that the law has not kept pace with changes in technology and that our love of gadgets comes at a cost to privacy.
Like cell phones, GPS devices "ping," or send out a test signal, at set intervals -- usually about every 30 seconds -- to update their location. It is the record of these signals that enables police to track where vehicles or people have been.
Susan Fast and her Lexus SUV disappeared from her home in the Tara subdivision on June 29.
Detectives consider her stepson, 52-year-old Thomas Fast, a suspect in her disappearance and death. He is in the Manatee County jail on charges of carrying a concealed weapon and stealing his stepmother's car. He has not been arrested for homicide. Yet investigators say they are building a case against him.
Susan Fast's SUV was found near a vacant home in east Bradenton.
At the request of investigators, Lexus provided maps showing areas where the SUV had recently traveled, said Sheriff's Office spokesman Randy Warren.
Warren said the maps were vague and showed several areas.
"They didn't give us times; they only showed us that the vehicle was in that area," Warren said. "That was one of the issues. If we had times, that would have been great."
Using the maps, detectives searched several areas before finding the body in the pond.
"We got lucky," sheriff's Detective Ricardo Alvarado said. "The GPS was huge."
Fast's case is the latest example of the role technological sleuthing plays in law enforcement.
In 2000, Charles Daniels was arrested in the murder of a man in a New Orleans suburb. Daniels initially said he was nowhere near the murder scene, but he confessed when GPS data from his truck showed differently.
"If GPS is polling these satellites and we know which vehicle and we know which satellite, then we can track movements retroactively," said Aric Dutelle, a professor who teaches forensic investigation at the University of Wisconsin-Platteville. "It's all computerized; it's all digital, so there's always records."
Most devices have memories that store where the device has been, said Jessica Meyers, a spokeswoman for Garmin, a company that designs and manufacturers GPS devices.
"It would be essential to have the device (for an investigation), as most GPS devices only receive a signal; they do not send a signal," Meyers said.
Beyond navigation, GPS can be used as a tracking device. These tracking devices can be used to locate a stolen or lost car, but in some cases law enforcement and private individuals have used the devices to track other people.
Internet companies sell tracking devices, advertising them as useful for keeping tabs on a spouse suspected of having an affair. The devices can run on small batteries and attach to the underside of a vehicle with a magnet.
But civil liberties advocates warn that, in their embrace of technology, people are unwittingly creating a record of their movements.
"We plant the devices on ourselves -- a cell phone can show where you've been," said Lee Tien, an attorney with Electronic Frontier Foundation, a nonprofit agency focused on protecting privacy rights from advances in technology.
"The law has not moved to deal with this."
Copyright 2007 Sarasota Herald-Tribune Co.
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