Justice

Who’s Tracking Your License Plate?

Automated license plate readers are collecting and sharing tons of data across state lines, according to records from nearly 200 police departments nationwide.
San Diego County Deputy Sheriff Ben Chassen drives a police car fitted with technology that reads the license plates.Gregory Bull/AP

Over the last decade, cities have increasingly embraced the crime-fighting potential of automated license plate reader (ALPR) technology. These camera systems are now ubiquitous at malls and train stations; they appear on street signs and perch on the dashboards of police cars. ALPRs can snap up thousands of geotagged photos per minute, and can help construct an incredibly detailed picture of a driver’s whereabouts over time.

For law enforcement, ALPR represents a powerful tool that can track suspects in real time. Let’s say the police are pursuing a robber fleeing in a vehicle. They can add the suspect’s license plate to a “hot list” and receive alerts whenever an ALPR camera in their city snaps a picture of it. Using what’s essentially a real-time map, the police can track and intercept the suspect.