In a growing trend among law-enforcement agencies, the West Virginia state police say license plate scanners installed on police vehicles are responsible for 25 felony arrests during the past six months, according to published reports.
The license plate reader being used is ELSAG North America Law Enforcement Systems’ “Mobile Plate Hunter-900” (MPH-900), and each device equips a police cruiser with three different cameras. One of the cameras is positioned to face away from the cruiser at a 90-degree angle, while a second is deployed at the front left corner of the vehicle (to scan oncoming traffic for front-facing license plates), and a third camera is positioned at the rear left (to scan vehicles after they have passed).
The devices scan the characters on license plates in the background, as officers complete other tasks such as driving or taking emergency calls. The characters on a license plate are run through the officer’s in-car computer, which is updated twice a day with a list—supplied by the National Crime Information Center (NCIC)—of license plate numbers from stolen vehicles and vehicles used to commit felonies.
On a good day, the cameras scanned about 10,000 license plates per day, a number that far surpasses the number of license plate checks that a trooper could accomplish by manually searching the system with each passing car, say troopers.
However, the scanner is “not a substitute for good police work,” says Sr. Trooper Malcolm Napier. "The cameras look for license plates that have been entered into the NCIC, but if the biggest criminal in town is driving by and his plates haven't been entered into the system, then it's not going to go off on him."
The devices are not perfect, Napier added. The scanners cannot distinguish between state license plates, a New York plate will read as a West Virginia plate, and the scanners have reported such out of state vehicles as stolen when they were not.
Nonetheless, the technology does work, and has recovered stolen vehicles and stolen plates, which, on at least one occasion, the vehicle the plates were attached to was found to contain stolen goods. It has also been useful in a murder investigation, helping troopers find a vehicle that was involved in a fatal shooting.
Because of the state police’s success with the scanners, other West Virginia law enforcement agencies (the Charleston Police and the Kanawha County Sheriff's Department) are also pursuing scanners.