Sgt. Julio Valcarcel wheels his unmarked sport utility vehicle south onto U.S. 1 in Jessup as motorists whiz by in the opposite direction. The Maryland state trooper is not looking to ticket speeders, but rather is on the hunt for stolen cars.
And he doesn't have to consult a "hot sheet" to compare license plate numbers, or even remember the make, model and color of vehicles on the stolen-car list.
Images of license plates pop onto his laptop computer screen as the cars go by. An alarms sounds when the computer finds a stolen plate or car, or even a revoked or suspended registration, information stored in a database updated daily by the FBI and the Maryland Motor Vehicle Administration.
"It's constantly taking pictures, looking for license plates," said Valcarcel, who has spent 21 years as a trooper and is now the technical manager of the license plate reader program. "There might not be a violation at the time we capture that read, but the read might be helpful for investigative purposes down the road."
State police have been using the plate reader technology since 2004, but the program is getting a new influx of money — including a $2 million state grant last summer — doubling the funding. Officials give the devices part of the credit for a nearly 40 percent drop in car theft across the state in the past three years.
But the system has limits.
Hours after Maryland State Police Trooper Shaft S. Hunter was killed on Interstate 95 on May 21 when his cruiser slammed into the back of a tractor-trailer while chasing a speeding motorcycle, authorities said they hoped to identify the motorcycle's driver using a license plate reader. There is a stationary reader on the highway near Route 32, close to the crash site.
Valcarcel said that reading smaller motorcycle tags is more difficult than license plates on cars or trucks. The reader can't scan numbers on vehicles exceeding 120 mph or motorcycle tags that have been mounted inside wheel wells or are obscured by fenders.
Doug Ward, who spent 27 years with the Maryland State Police and now is the director of the Johns Hopkins School of Public Safety, said that racing motorcycles, sometimes speeding at 160 mph, are as big a blur to the plate readers as they are to the motorists they pass.
Ward said that plate readers used at toll plazas often have a difficult time reading tag numbers on motorcycles that are stationary, let alone motorcycles traveling at triple-digit speeds.
But Valcarcel said investigators are hoping to find witnesses to the accident by reading the plates of cars that were in the same area when Hunter crashed. The man who owned the truck that Hunter hit told police that a motorcyclist wearing a white helmet flew by him at a "high rate" of speed.
Said Ward: "I applaud them for trying and doing everything they can. I hope somebody steps forward."
A single license plate reader unit costs about $20,000 and can read as many as 5,000 license plates in a typical eight-hour shift. Mobile cameras are typically mounted on the trunks of police cruisers, and stationary cameras are put in strategic spots along Maryland's interstates and at toll plazas at the Bay Bridge and Fort McHenry tunnel.
Most police agencies in the Baltimore area have mobile license plate readers, as do many across the country. Baltimore police spokesman Anthony Guglielmi said that 10 have been ordered for the city Police Department. The Regional Auto Theft Task Force, made up of officers from several jurisdictions, including Baltimore City and Baltimore County, have 11, many mounted on large SUVs.
The state police have 19 units, all but one of them mobile, according to Valcarcel. One of the benefits is being able to read dozens of tags in a matter of moments. Officers with equipped cruisers can simply drive up and down streets, quickly scanning tags of every parked car and instantly knowing whether one has been stolen.
Justin Mulcahy, a spokesman for the Anne Arundel Police Department, said that since fall, the technology has helped his department recover six stolen vehicles.
Capt. Don Roby, who oversees the license plate reader program for the auto theft task force, said there has been a "double-digit" drop in the number of vehicles reported stolen over the past several years.
The technology is now well-known that even suspected car thieves talk about the plate readers. "During our interrogations, they do bring it up," Roby said.
As the license plate readers become more widely used — even by parking lot owners to help people find their cars — so does the scrutiny. Privacy groups have raised concerns over law enforcement running plate numbers and collecting the data from people not suspected of breaking the law.
"We see no problem as long as the information is can be used legitimately, and used for narrowly tailored purposes" said Meredith Curtis, a spokeswoman for the American Civil Liberties Union of Maryland.