West Fargo Police Officers are using an Automated License Plate Recognition (ALPR) system as they patrol the streets of West Fargo. The ALPR is mounted on a patrol car and is used to locate vehicles which have been reported stolen or have been involved in a criminal act. The system became operational in June, and was purchased in part using federal grant funding. West Fargo is the first department in the state to operate the ALPR as part of their routine patrol duties.
ALPR technology uses a dedicated computer system and specialized cameras to capture license plate images. The system continually scans the camera's field of view for the presence of a license plate. As a license plate is detected, the camera captures both color and infrared images of the vehicle and plate. Infrared cameras are used because of their ability to capture images regardless of available lighting or other conditions which may infer with a standard camera. The system takes numerous photos using various camera settings to ensure the highest quality image is collected. The computer software selects the best photo and sends it on for processing.
During processing, the program reads the captured infrared plate image and converts it to a data file. The data file is automatically compared against a data base of stolen or wanted vehicle files. A match between files results in the officer receiving an alert message. The officer must visually confirm the match and then take appropriate action.
The data base is maintained by North Dakota State Radio and is updated twice daily. State Radio ensures the data base contains the most current information on vehicles reported stolen or wanted by law enforcement throughout the United States and Canada. In addition, the data base may be expanded locally to include vehicle information relating to AMBER Alerts, sexual offenders, criminal investigations, and drug enforcement.
ALPR technology was developed in the early 1990s and has found use in law enforcement, parking enforcement systems, access control, and homeland security.