The RCMP in the Northwest Territories has begun using roadside cannabis testing technology that has come under criticism from defense attorneys elsewhere in Canada.
Constables in the territory announced late last month that they had deployed devices designed to take a saliva sample and test for the presence of tetrahydrocannabinol, also known as THC, the main psychoactive substance in cannabis. They said the technology would help them detect drunk drivers and make roads safer.
But some criminal defense attorneys have expressed concerns about the ability of these devices to provide reliable test results, especially in cold weather. They argue that the technology is not effective in determining if someone is impaired.
“It can lead to the arrest of people who are actually innocent,” said Kyla Lee, a Vancouver-based attorney.
Lee said research has shown devices may be more likely to give false results in extremely cold temperatures, and movement during the scan could also affect results. She added that while the devices can provide a positive or negative test result, they do not indicate how much THC may be present in a person’s blood.
Lee recently represented a Nova Scotia woman in a constitutional challenge to the law that allows roadside drug testing technology in Canada.
Michelle Gray, who uses cannabis for multiple sclerosis, had her car confiscated and her license suspended for a week after failing a cannabis saliva test at a traffic checkpoint in 2019, even though she passed a sobriety test the same evening.
“The technology just doesn’t exist yet to allow police to determine drug impairment using physical equipment,” Lee said.
Lee is awaiting a decision on the constitutional challenge in Nova Scotia. She said she expects there will be further legal challenges in other Canadian jurisdictions where these devices are used, including the Northwest Territories.
There are two devices approved for roadside cannabis testing in Canada: the Drager DrugTest 5000 and the Abbott SoToxa mobile test system. The companies that manufacture the devices recommend using them at temperatures not lower than 4 C and 5 C, respectively.
Cpl. Andree Sieber of the Regina Police Department, who began using roadside devices to detect cannabis use in early 2020, said officers bring drivers to their vehicles for testing to avoid problems related to weather conditions or temperatures.
“We’ve used it all seasons here in Regina,” she said. “We have very cold winters and quite cold snowy days and you ask the person to come back with you in your vehicle where it’s heated and that’s no problem.”
Sieber said the more THC a person has consumed, the more likely they are to show signs of impairment and test positive.
The RCMP said roadside screening devices are just one tool they use to detect and investigate drug-impaired drivers alongside officers’ sightings. They said field sobriety tests and drug recognition experts remain the main enforcement tools.
“Police rely on what they see and hear, as well as what they smell when investigating impaired drivers,” the RCMP said in a written statement. “Regardless of how a drug is used, there are signs of that use and police are trained to recognize them.”
This report from The Canadian Press was first published on August 13, 2022.
This story was produced with the financial assistance of Meta and the Canadian Press News Fellowship.