The city of Denver is expanding its use of a technology that scans license-plate numbers and automatically alerts police when it spots a vehicle of interest.

Late in September, the city installed a camera system overlooking Federal Boulevard at its intersection with Sixth Avenue — the first permanent, stationary installation of the technology in the city.

The system autonomously searches for license plates that are associated with alerts about missing children and criminal activity. Police officers who have received training can use the system to view “live” data but not past records, according to police spokesperson Christine Downs.

“This LIVE data would include any predetermined ‘hits’ — such as Amber alerts, Medina alerts, vehicles associated with felony warrants, etc,” she wrote in an email to The Denver Post.

Denver already has 11 license-plate readers mounted in vehicles that it uses around the city, which it has operated for years, according to Downs. In a video published by the police department, an officer is shown identifying and pulling over two people with suspended and canceled driver’s licenses. Denver police didn’t immediately respond to a follow-up question about whether the new stationary system also would target such infractions.

The license-scanning program debuted in 2015. In its first 47 days alone, police used a single unit to read nearly a half-million plates, generating more than 9,000 “hits” on suspicious cars and resulting in 40 citations and 71 arrests. Its rollout prompted questions from the American Civil Liberties Union about the “false choice” between privacy and safety.

The city also has used license-plate readers to enforce parking meter time limits, look for vehicles with unpaid parking tickets and check for appropriate parking permits, according to an audit. Red-light photo cameras also use license plate numbers to ticket drivers.

The new installation on Federal cost $62,000; the department has no further plans for mounted cameras, according to Downs. Aurora and other Colorado cities also use stationary and mobile license-plate readers.

Councilman Paul López, who represents the area around Federal and Sixth, said he’d like to see the technology spread evenly across the city. The intersection is at the border of Barnum, Valverde, Villa Park and Sun Valley, home to some of the city’s Latino communities.

“It is a helpful tool,” López said. “It’s always been a helpful tool in identifying hit-and-run vehicles, stolen vehicles, vehicles that have been involved in crimes.

“However, it’s important and necessary and I would expect that it would be deployed all over the city, and not just in one area.”

López said he was disappointed that he hadn’t been notified of the stationary system’s deployment in his district.

State law says that agencies can only freely access images from the “passive surveillance” systems for a year after their creation. After that, they can access the archives to obtain evidence; the images must be destroyed after three years, according to the National Conference of State Legislatures.