An official from the wealthy Phoenix, Arizona, suburb that has begun to mount stationary license plate readers in fake cacti told Ars that its soon-to-be-deployed 15 license plate readers are primarily designed to thwart burglaries.

Just how many burglaries were there in Paradise Valley, Arizona, in 2014? Only 55.

"We're hoping that this technology will give us another tool in those burglary crimes," Kevin Burke, the town manager, told Ars.

But even long before the acquisition of LPRs, burglaries were already steadily falling. In 2013, there were 63 burglaries, while in 2012, 67. Criminals had their heyday in 2011, when there were 195 reported burglaries.

The town has recently experienced a small uptick in burglaries: in February 2015, the most recent month where data is available, the city was plagued with seven burglaries. The previous month, there were six, and in December 2014, there were just four.

The Paradise Valley Police Department (PVPD), like many other departments nationwide, uses these specialized cameras to scan cars and compare them at incredible speeds to a "hot list" of stolen or wanted vehicles. In some cases, that data is kept for weeks, months, or even years.

Earlier this year, Ars obtained 4.6 million LPR records collected by the police in Oakland, California, over four years and learned that just 0.16 percent of those reads were "hits." We discovered that such data is incredibly revelatory—we were even able to find the city block where a member of the city council lives using nothing but the database, a related data visualization tool, and his license plate number.

Sittin' pretty

According to the city’s own demographic figures , the median household income in the town of 12,820 is over $131,000, and more than 72 percent of "owner-occupied units" are valued at $1 million or more.

Burke also said that an anonymous source donated $234,000 to the police department, which will eventually fund 11 fixed license plate readers (LPRs) and a camera for four of the town’s six patrol cars.

While he understands that putting an LPR in a fake cactus might sound ridiculous, it’s apparently entirely consistent with the local residents’ willingness to pay large amounts of money to preserve its beauty.

"Everything in Paradise Valley is about the aesthetics," Burke said.

"We'll spend tens of thousands to cover up an electric box. We'll spend hundreds of thousands to camouflage an electric substation. Our residents have spent hundreds of thousands or millions to bury overhead cables. Ugly posts are things that we do not want. But we do want people to know that these technologies are there. Probably we'll end up putting a sign on it—half of the deterrent is knowing that people are there."

Of the fixed LPRs, three have been installed so far in fake cactuses, with two more installed on traffic lights. The fixed cameras are not yet operational, but the ones on patrol cars have been active since earlier this month.

No data for you

Further Reading Wealthy California town approves license plate readers along municipal border

Burke also told Ars that the city will be retaining the LPR data for six months and would not be releasing the entire dataset, nor would it be releasing individual records under the state public records act. He argued that the city does not want to get involved in domestic disputes, such as one person retrieving information on an estranged partner.

"The purpose is not to track the movement of day-to-day drivers, but the purpose is to match it against the Department of Public Safety's hotlist," Burke added. "It's collected for law enforcement purposes and used for law enforcement purposes, not for tracking purposes."

The city official provided a six-page document outlining the police’s policy on the use of LPRs and related data.

That document states:

Access to LPR data is restricted to authorized PVPD members and will be used only for bona fide law enforcement purposes. All data collected will be used in accordance with Department policy, and State and Federal law that appropriately balance the need for the Department to respond to criminal activity and investigations against the legitimate privacy interests of persons operating motor vehicles on the streets of the Town of Paradise Valley.

However, the policy lacks any sort of description of logging or auditing, nor does it describe any sort of enforcement mechanism for an official that abuses access to the database.

So how will Burke know if the LPRs are working?

"I'll be looking for higher clearance rates related to burglaries," he said. "Or just a reduction in the number of burglaries. There's probably some deterrent in terms of knowing it’s there."