About ALPR

Law enforcement officers are often searching for vehicles that have been reported stolen, are suspected of being involved in criminal or terrorist activities, are owned by persons who are wanted by authorities, have failed to pay parking violations or maintain current vehicle license registration or insurance, or any of a number of other legitimate reasons. Victims and witnesses are frequently able to provide police with a description of a suspect vehicle, including in some cases a full or partial reading of their license plate number. Depending on the seriousness of the incident, officers may receive a list of vehicles of interest to their agency at the beginning of their shift, or receive radio alerts throughout the day, providing vehicle descriptions and plate numbers including stolen vehicles, vehicles registered or associated with wanted individuals or persons of interest, vehicles attached to an AMBER alert, missing persons alert, and Be On the LookOut - or BOLO - alerts. These lists can be sizable depending on the jurisdiction, population size, and criteria for the list, and can present challenges for the patrol officer.

ALPR systems function to automatically capture an image of the vehicle’s license plate, transform that image into alphanumeric characters using optical character recognition or similar software, compare the plate number acquired to one or more databases of vehicles of interest to law enforcement and other agencies, and to alert the officer when a vehicle of interest has been observed. The automated capture, analysis, and comparison of vehicle license plates typically occurs within seconds, alerting the officer almost immediately when a wanted plate is observed. 

ALPR automates a tedious, distracting, and manual process that officers regularly complete in their daily operations of searching for wanted vehicles. ALPR systems vastly improve the efficiency and effectiveness of officers in identifying vehicles of interest among the hundreds or thousands they observe during routine patrol. In doing so, ALPR can identify that needle in a haystack -- the stolen car, the vehicle wanted in connection with a robbery or a child abduction, or the vehicle registered to a missing person.

Many states will consider legislation in 2015 regarding the use of ALPR by law enforcement.  As stakeholders engage in the debate, it is important to have a clear understanding of how ALPR works, best practices in the management and use of the technology and the data it provides, and effective policies that enable law enforcement to maximize the benefits of the technology while aggressively protecting the privacy and civil liberties of all citizens in their communities.  This website is a resource for law enforcement associations, agencies, and individuals, as well as industry partners, privacy advocates, and legislators to better understand the host of operational, policy, and technical issues associated with ALPR planning, use, and deployment.