B.C.'s privacy commissioner is telling Victoria police to stop sharing personal data collected by automatic licence plate scanners on the activities of law-abiding citizens.

Automated Licence Plate Recognition systems are mounted in police squad cars. They automatically photograph, scan and record the licence plate numbers and locations of other vehicles as the officer drives around during a shift.

The ALPR system compares this data to an on-board database of plate numbers provided by the RCMP called an alert listing.

A hit occurs when there is a match between a licence plate scan and the alert listing. If there is no match, the item is categorized as a non-hit.

The Victoria Police Department has been using the technology to search for hits of vehicles on the alert list issued by the RCMP.

At the end of each shift the "daily scan" record is turned over to the RCMP who then remove the personal identity from any scans that did not yield a hit on the alert list.

But Commissioner Elizabeth Denham said the Victoria Police Department has no legal right to disclose any data whatsoever from the non-hits to the RCMP.

"Non-hit data is personal information about the suspicion-less activities of citizens — information that the police have no reason to believe relates to criminal activity," said Denham in a statement issued on Thursday morning.

"This information is not serving a law enforcement purpose and therefore, VicPD cannot disclose it to the RCMP," said Denham.

Denham recommended the ALPR system be reconfigured to delete non-hit data immediately after the system determines that it is not a match.

She noted her provincial mandate gives her office the authority to issue an order for changes if municipal police departments don't comply, but her office does not have jurisdiction over the federal RCMP.

Victoria police chief disagrees

Chief Constable Jamie Graham said he disagrees with the Denham's findings that Victoria police were revealing non-hit data to the RCMP

"This data is transferred to the RCMP for the sole purpose of its destruction," said Graham in a statement issued on Thursday morning.

Chief Jamie Graham's says he disagrees with the privacy commissioner's conclusion. (CBC)

The chief said the scanning system had been tremendously successful at spotting prohibited drivers, uninsured vehicles and invalid license plates.

"In fact, recent deployments of the technology have resulted in the detection of violations in such numbers that it often exceeded our officers’ ability to keep up with the volume of violations.

Graham did not say specifically if Victoria police will comply with Denham's recommendations.

"The Department remains committed to maintaining public safety through effective law enforcement while being mindful of the need to protect personal privacy."

Surveillance of citizens

In her review of the scanning program, Denham also expressed concern that some law enforcement agencies have recently discussed retaining the non-hit data.

She also clarified that future use or disclosure of non-hit data in the ALPR program by municipal police was illegal.

While her investigation focused on the Victoria police sharing data with the RCMP, the program also notifies police when there is a match in any of several databases, including stolen vehicle information in the Canadian Police Information Centre, expired licences in ICBC's registry, and outstanding warrants in the PRIME-BC police database.

"There are concerns that this technology could be used as a surveillance tool, where data about the location and activities of citizens is used for purposes other than that for which it was collected.

B.C. privacy commissioner Elizabeth Denham says police must stop sharing personal data on the law abiding activities of citizens collected by automatic licence plate scanners. (CBC)

"In light of these concerns, I felt it was important to provide citizens with a comprehensive look into how this technology is being used," Denham wrote.

"Collecting personal information for traffic enforcement and identifying stolen vehicles does not extend to retaining data on the law-abiding activities of citizens just in case it may be useful in the future," said Denham.

Denham said her investigation was launched after three members of the public raised concerns about the use of the technology and its implications on people's privacy.