The facial recognition technology locks on once you’re in range.

Benji Hutchinson works for NEC, a company that sells the software, gave CBS News a demonstration.

“It’s putting the green box around us, and displaying our name,” Hutchinson said.

Cameras equipped with the software can match a person’s face to others in a database.

The technology could have helped after the Boston Marathon bombing. Investigators there reportedly had to sift through 120,000 photos and nearly 13,000 videos before identifying Dzhokar Tsarnaev.

“We could have gotten the match in seconds,” Hutchinson said.

In Baltimore, the police department used facial recognition during the 2015 riots to identify looting suspects.

But increasing use of the technology has raised privacy concerns.

“There is not one law in any state or in Congress that comprehensively says this is when you can use the technology and this is when you can’t,” said Alvaro Bedoya, author of a Georgetown Law School study on facial recognition.

The study found 26 police departments use the technology and 16 states allow the FBI to tap into their systems. Photos are culled from social media images, driver’s licenses and government identifications.

The report argues the “biometric network primarily includes law-abiding Americans.”

Boston bomber Dzohar Tsarnaev’s picture in the database  CBS NEWS
Boston bomber Dzohar Tsarnaev’s picture in the database  CBS NEWS

“Maryland enrolled 4 million drivers in its system, and ask a Marylander do they know they’re in a lineup that is scanned thousands of times a year without warrants, and I’m pretty sure they’ll be surprised about that,” Bedoya said.

Maryland officials say they limit access to the technology, and the FBI says the technology is crucial to catching terrorists and criminals.