An armed robber burst into a Northeast Washington market, scuffled with the cashier, and then shot him and the clerk’s father, who also owned the store. The killer sped off in a silver Pontiac, but a witness was able to write down the license plate number.
Police figured out the name of the suspect very quickly. But locating and arresting him took a little-known investigative tool: a vast system that tracks the comings and goings of anyone driving around the District.
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.
“It’s a perfect example of how they’d be useful,” said Lt. T.J. Rogers, who is responsible for the 26 tag readers maintained by the Fairfax County police. “We see a lot of potential in it.”
The plate readers are different from red-light or speed cameras, which issue traffic tickets and are tools for deterrence and enforcement. The readers are an investigative tool, capturing a picture of every license plate that passes by and instantly analyzing them against a database filled with cars wanted by police.
Police can also plug any license plate number into the database and, as long as it passed a camera, determine where that vehicle has been and when. Detectives also can enter a be-on-the-lookout into the database, and the moment that license plate passes a detector, they get an alert.
It’s that precision and the growing ubiquity of the technology that has libertarians worried. In Northern Virginia recently, a man reported his wife missing, prompting police to enter her plate number into the system.
They got a hit at an apartment complex, and when they got there, officers spotted her car and a note on her windshield that said, in essence, “Don’t tow, I’m visiting apartment 3C.” Officers knocked on the door of that apartment, and she came out of the bedroom. They advised her to call her husband.
A new tool in the arsenal
Even though they are relatively new, the tag readers, which cost about $20,000 each, are now as widely used as other high-tech tools police employ to prevent and solve crimes, including surveillance cameras, gunshot recognition sensors and mobile fingerprint scanners.
License plate readers can capture numbers across four lanes of traffic on cars zooming up to 150 mph.
“The new technology makes our job a lot easier and the bad guys’ job a lot harder,” said D.C. Police Chief Cathy Lanier.