Scores of cameras across the city capture 1,800 images a minute and download the information into a rapidly expanding archive that can pinpoint people’s movements all over town.
Police entered the suspect’s license plate number into that database and learned that the Pontiac was on a street in Southeast. Police soon arrested Christian Taylor, who had been staying at a friend’s home, and charged him with two counts of first-degree murder. His trial is set for January.
More than 250 cameras in the District and its suburbs scan license plates in real time, helping police pinpoint stolen cars and fleeing killers. But the program quietly has expanded beyond what anyone had imagined even a few years ago.
With virtually no public debate, police agencies have begun storing the information from the cameras, building databases that document the travels of millions of vehicles.
Nowhere is that more prevalent than in the District, which has more than one plate-reader per square mile, the highest concentration in the nation. Police in the Washington suburbs have dozens of them as well, and local agencies plan to add many more in coming months, creating a comprehensive dragnet that will include all the approaches into the District.
“It never stops,” said Capt. Kevin Reardon, who runs Arlington County’s plate reader program. “It just gobbles up tag information. One of the big questions is, what do we do with the information?”
Police departments are grappling with how long to store the information and how to balance privacy concerns against the value the data provide to investigators. The data are kept for three years in the District, two years in Alexandria, a year in Prince George’s County and a Maryland state database, and about a month in many other suburban areas.
“That’s quite a large database of innocent people’s comings and goings,” said Jay Stanley, senior policy analyst for the American Civil Liberties Union’s technology and liberty program. “The government has no business collecting that kind of information on people without a warrant.”
But police say the tag readers can give them a critical jump on a child abductor, information about when a vehicle left — or entered — a crime scene, and the ability to quickly identify a suspected terrorist’s vehicle as it speeds down the highway, perhaps to an intended target.
Having the technology during the Washington area sniper shootings in 2002 might have stopped the attacks sooner, detectives said, because police could have checked whether any particular car was showing up at each of the shooting sites.