In the first 47 days that Denver police used new license-plate scanner technology, they recovered 52 stolen cars.

And for half of that time, only one scanner was being used in the city’s six districts.

Overall, according to department records, the new system “read” 457,155 cars, resulting in 9,341 “hits” — cars or registered owners suspected of breaking the law.

Based on that, police have issued 40 citations, and made 11 felony arrests and 60 misdemeanor arrests.

On May 1, when the technology was rolled out with six vehicles citywide, Denver police spotted more than 30 vehicles or owners suspected of law-breaking during the first hour or so.

Officials were so excited that they immediately called Police Chief Robert White to share the news.

And White was excited, too.

“It’s another tool that we can use to address crime issues — and any tool that we can use to prevent crime, I’m pretty excited about,” he said.

The scanners — cameras mounted on top of police cruisers that send license-plate data to computers inside the vehicles — can almost immediately give details on any criminal issues associated with the passing cars.

“A game-changer”

Department officials have called the scanners “a game-changer,” a sentiment in keeping with the agency’s embrace of technological toys such as the HALO cameras, its burgeoning body-camera program and an increasing reliance on data-driven policing.

The HALO system is credited with helping Denver police detectives identify, track and capture a taxi driver suspected of sexually assaulting a woman shortly before Christmas.

But the increasing use of the new toys has raised some old questions regarding how far law enforcement is willing — or should be allowed — to go in the name of policing.

Police departments across the country, including some in Colorado, were arming themselves with military equipment, ranging from armored Humvees to rocket launchers, bought at reduced prices from the U.S. government.

Such equipment was highly visible during recent disturbances such as the rioting in Ferguson, Mo., and sparked debate about paramilitary overkill.

Gear sales banned

Just over a week ago, President Barack Obama banned further sales of some of the gear.

Now, some people question whether there needs to be a brake on the technological equipment as well.

“When I heard about the scanners, I just said, ‘Really?’ ” said Denise Maes, the public policy director for the American Civil Liberties Union of Colorado.

“I’m sure there’s a certain amount of law enforcement benefit to finding stolen cars,” Maes said, “but we give up a lot of privacy for what we think is in the name of public safety, and I always wonder if that’s something of a false choice.”

Maes wonders whether the technology will put some neighborhoods under more scrutiny than others.

Police counter that the specially equipped vehicles are equally distributed among the department’s six districts, with one in each.

And although police say their Data-Driven Approaches to Crime and Traffic Safety analysis can specify the likelihood of criminal activity happening at a particular time or place, they insist there won’t be any trampling of civil rights.

“We’re not targeting neighborhoods or individuals — and it’s not like we’re actively looking at every individual walking down the street,” said Deputy Chief of Operations David Quinones.

The department launched its use of body cameras in 2013, with the goal of outfitting 800 officers by this year.

But questions began to arise during a six-month pilot program that ended in December.

Sharing of scanner data

At a series of public forums, citizens wondered whether police could or would alter video footage. Maes wondered how long the footage would be kept and what the guidelines for sharing it with other law enforcement agencies would be.

Those questions were not specifically answered, although Denver police had indicated license-plate scanner data will be kept for just under one year.

Mitchell and police say there’s disagreement on how the numbers should be interpreted.

White says he’s sensitive to the public’s concerns — to a point.

“People are going to question the body cameras; people are going to question lots of things we use,” he said. “But these are effective tools to help fight crime.”

And, increasingly, it seems clear that the technology isn’t going to go away.

“These are very interesting times we live in,” said Lt. Chris Peters of the Parker Police Department, which launched its two-month body-camera pilot program in late March.

“People — citizens or police officers — have to know that in this day and age, there’s a high chance that you’re being recorded, whether it’s on a HALO camera or on somebody’s cellphone at Walmart.

“We’re all just under surveillance all the time.”

Anthony Cotton: 303-954-1292, acotton@denverpost.com or twitter.com/anthonycottondp