The number of automatic licence plate readers being used to scan vehicles in Saskatoon will double when the Saskatoon Police Service buys two new devices in August.

Police say no personal information collected by the readers will be shared with other police services. The devices have been controversial in other parts of North America due to privacy concerns.

The service said it does share rough data with other police agencies at provincial traffic meetings, where SGI would also be present as a partner.

"We share numbers of hits, number of enforcement actions based upon the hits and the general value of the tool," said the police service in an emailed response to questions.

"We use ALPR numbers to test the value of the system. No personal information is shared."

Devices allow quicker access to data

The readers, known as ALPRs, use infra-red technology to scan plates as police travel around the city. Officers are alerted if a plate is linked to a person wanted by police, a stolen or unregistered vehicle, or a suspended driver.

"For one person to do that manually, one officer, would take such a long time," said SPS traffic unit Staff Sgt. Judy McHarg.

"This way we get quick and easy access and all the data is right there."

The SPS currently has two ALPRs. Of the 11,000 "hits" picked up by the scanners in 2016, tickets were issued for 1,323.

The police service said only three of those hits were for stolen vehicles in 2016. So far this year the scanners have identified seven stolen vehicles.

The storage of information collected by ALPRs has raised privacy concerns that the devices could be used for other purposes, such as tracking a person's location over time.

In B.C., police changed their procedures after the province's privacy commissioner raised concerns about how long "non-hit" data was being stored on RCMP computers.

In 2014, when the number of scanners being used by police forces across Saskatchewan increased from 13 to 20, SGI said the information from scans that did not result in 'hits' would be deleted.

Hit info kept for 90 days

But Saskatoon police said information collected by its scanners is kept for 40 days, and plates that register as a hit would be kept for 90 days.

Sharon Polsky, the president of the Privacy and Access Council of Canada, raised concerns that information collected by police could be shared with other organizations and kept indefinitely.   

"If that is the only use that they put this information to then certainly it meets the requirements for detecting, preventing and investigating criminal activity," said Polsky.

"But it's a slippery slope and human nature and police agencies and all sorts of organizations, once they have a technology, it's that 'purpose-creep'."

ALPR traffic stops same as any other: police

Police said passengers in a vehicle stopped by an ALPR could also be questioned by officers about the violation picked up by the ALPR. For example, police said, a passenger in an unlicensed vehicle might be questioned about who usually drives the vehicle or who owns it.

"The degree of investigation is dependent upon the initial stop and may change based upon the information that the officer receives at roadside," said the police service.

"Examples may include alcohol or drug consumption."

The police service said the same standards apply to an ALPR hit as any other standard traffic stop, adding that the Supreme Court of Canada allows officers to stop drivers to check for vehicle registration, driver impairment and vehicle safety equipment.  

According to police data, the majority of ALPR hits picked up by Saskatoon police are for expired plates, followed by suspended drivers, unlicensed plates and stolen vehicles.