Police Using G.P.S. Units as Evidence in Crimes
Published: August 31, 2008
Like millions of motorists, Eric Hanson used a Global Positioning System device in his Chevrolet TrailBlazer to find his way around. He probably did not expect that prosecutors would use it, too — to help convict him of killing four family members.
Prosecutors in suburban Chicago analyzed data from the Garmin G.P.S. device to pinpoint where Mr. Hanson had been on the morning after his parents were fatally shot and his sister and brother-in-law bludgeoned to death in 2005. He was convicted of the killings this year and sentenced to death.
Mr. Hanson’s trial was among recent criminal cases in which the authorities used such navigation devices to help establish a defendant’s whereabouts. Experts say such evidence will almost certainly become more common in court as the systems become more affordable and show up in more vehicles.
“There’s no real doubt,” said Alan Brill, a computer forensics expert in Minnesota who has worked with the Federal Bureau of Investigation and the Secret Service. “This follows every other technology that turns out to have information of forensic value. I think what we’re seeing is evolutionary.”
Using technology to track a person’s location is nothing new, but the popularity of the Global Positioning System — in cars, cellphones and other handheld devices — gives the authorities a powerful tool to track suspects.
In September, a man in Butte, Mont., pleaded guilty to rape after a judge ruled that evidence from the global positioning unit in his car could be used against him at trial. Prosecutors planned to use it to show that the man, Brian D. Adolf, “prowled” in the town looking for a victim.
In New Brighton, Pa., a trucker’s system led the police to charge him with setting his own home on fire. The system’s records showed his rig was parked about 100 yards from his house at the time of the fire.
Critics, however, say the police should be allowed to acquire global positioning data only by getting a warrant. Renée Hutchins, a University of Maryland law professor, wrote an article recently suggesting Global Positioning System data was protected under the Fourth Amendment.
“I think that in the last couple of years,” Ms. Hutchins said, “people are starting to be aware that if they have these units in their car, people can keep track of you. I think it’s a growing public awareness. The problem is that most people feel like, ‘I’m not doing anything wrong, so who cares?’ But I think that’s the wrong way of looking at it.”
Developed for the military, the navigation devices started showing up in cars in the 1990s. Prices have dropped sharply in the past few years, and many units cost less than $150. The Consumer Electronics Association estimates that 20 percent of American households own a portable Global Positioning System unit and that 9 percent have vehicles equipped with in-dash systems.