ST. LOUIS — As officer Bob Bates maneuvers his patrol car south on Jefferson Avenue, the computer mounted on the center console lets out a series of high-pitched tones.
Bates' eyes are locked on the road, but a high-tech system installed in the squad car is focused on the license plates of the vehicles around him.
Ping. Ping. Ping.
With each passing car, the computer registers a license plate number. Tiny cameras mounted atop the patrol car snap photos of each plate, feeding information into the computer.
While Bates changes lanes, the computer is checking to see if the car in front of him has been reported as stolen, is connected to a felony crime or is the focus of a search by police across the country.
"It's basically like having a partner that's reading the hot sheet constantly," Bates said, referring to the daily crimes summary.
St. Louis police will soon have the "automated license plate recognition system" technology installed in three department squad cars.
The license plate scanners are growing in popularity among area departments. Town and Country police were the first to begin using the system, in 2008. St. Louis County, Chesterfield and Richmond Heights police also are among a handful of departments to have at least one car equipped with the scanners.
"It's something that makes our job easier and it's another tool for the community that makes us a little bit safer," said St. Louis police Lt. Ronald Danback.
He oversees the system in the city's 4th District, which covers downtown and has higher levels of car-related crime than other parts of the city because of the influx of weekday workers, tourists and late-night drinkers.
In St. Louis, Bates and other officers use the license-plate scanning car during normal patrols. The system is constantly working as officers respond to calls. The scanners can capture about 3,600 plates per hour, can be effective in the dark and reportedly can recognize a plate passing at up to 160 mph.
The system also stores the time and GPS coordinates of every plate it photographs, providing police with a useful backtracking tool should the need ever arise.
Once a license plate is scanned into the police database, the computer cross-checks the plate with police records to see if it matches any stolen vehicles, wanted subjects, Amber Alerts, the sex offender registry or any plate manually entered in by officers.
In the first five months that the system was up and running in the city, it had 37 felony crime hits, 65 stolen vehicles and 228 matches for wanted vehicles in the national crime database.
One day, as Bates handled a minor traffic crash on Highway 40 downtown, the scanner recorded 10 license plate hits of vehicles passing his car on the highway while he worked the scene.
"It's almost like having an extra set of eyes with you," Danback said.
The first system was paid for by Lumière Place in an effort to help cut down on car-related crimes — a common problem — around the casino. In November, State Farm Insurance donated $23,000 for a second system. And the St. Louis Police Foundation soon will be donating funds for another.
All of the systems used in the city are made by Federal Signal Co. of Knoxville, Tenn.
Several area departments recently met to talk about creating a searchable computerized database that will help share license plate information.
The goal, said Capt. Gary Hoelzer of the Town and Country Police Department, is to help departments coordinate and communicate investigations of car thefts, car break-in suspects or other regional crimes.
Hoelzer said the scanner recently helped with the arrest of a suspect wanted in a series of burglaries in different municipalities in the central St. Louis County area.
Hoelzer said interest in the system is increasing among St. Louis-area departments.
"It's been every effective," Hoelzer said. "It's done what it's marketed to do."
When St. Louis County was testing the system with Town and Country's car, Hoelzer said it led to a half dozen arrests during one shift on a North County precinct patrol.
Richmond Heights police detective Sgt. Doug Schaeffler agrees the system is another useful tool for officers.
"It's doing what we've always done, but better," Schaeffler said.
Richmond Heights has had the system in one car for about nine months. The system cost about $20,000, Schaeffler said, and was partially paid for with grant money. The scanner is particularly effective in the parking lots of the St. Louis Galleria mall.
With the sharing technology or even by just communicating between departments by e-mail or phone, Richmond Heights can search for a suspect vehicle that may be targeting area shopping malls.
The scanners have met with some criticism. Civil rights groups in New York, Ohio and California have raised privacy concerns about the license plate scanning technology. The ACLU branch in Ohio claimed the scanners may increase racial profiling.
But police in the St. Louis area said that because the technology focuses only on the license plates of vehicles and not the drivers, the scanners help prevent profiling.
Back in the city, Bates has been driving around for an hour with nary a "ping."
But as he slowly drives down Destrehan Street on the near north side, a red bar flashes across his laptop. "Media Alert," it reads.
Bates pulls up the scanned plate in the police department system, finding out the car next to him was reported stolen in mid-January. It turns out the car was recovered by the owner, who never notified police.
At least, Danback says, police can clear the case and avoid pulling over the owner on suspicion of car theft in the future.