TUCSON, Ariz. — A ruling by one of the state's highest courts sets a "high" bar when it comes to suspending licenses for marijuana DUIs.
The ruling by the Arizona Court of Appeals establishes a new standard for handling marijuana DUIs. The court ruled that the state must now prove actual impairment rather than relying solely on the presence of THC metabolites in a driver’s blood to suspend their license.
Previously, detecting THC in a driver’s system was enough to trigger a suspension.
Julie Gunnigle, Legal Director for Arizona NORML, explained that THC metabolites can remain in the bloodstream long after marijuana use, complicating DUI cases.
“They can test positive for those metabolites days or weeks, and in some cases even months after consumption,” Gunnigle said.
She emphasized that this ruling now requires proof of impairment at the time of driving, rather than just evidence of prior use.
"What this case stands for is the idea that just because someone tests positive for THC metabolites in their system, it does not automatically mean their driving privileges get suspended," she said.
The change comes after Arizona voters legalized recreational marijuana for adults in 2020 under Proposition 207.
Despite the new law, law enforcement officers face challenges in detecting marijuana impairment.
Unlike alcohol, where officers can use a breathalyzer to measure intoxication, marijuana’s effects are more difficult to quantify.
“It can’t be measured in the same way,” Gunnigle noted. “Where, for example, an officer at a traffic stop could ask someone to blow and you can tell how much alcohol is in their system.”
Deputy Anthony Pool, who leads the Pima County Sheriff’s DUI unit, said the department’s approach to marijuana DUIs will remain largely unchanged.
“Nothing has changed in our objective here with the Pima County Sheriff’s Department,” Pool said.
He explained that officers will continue to focus on identifying impaired drivers through field sobriety tests and other signs of impairment.
“We do a really, really good job of administering field sobriety testing and also documenting that as well, and making sure that we’re distinguishing between consumption versus impairment,” Pool said.
Although rudimentary devices meant to detect marijuana impairment exist, none are currently used by Arizona law enforcement.
The ruling highlights the importance of officers gathering clear evidence of impairment before suspending a driver’s license.
Pool stressed that the department’s priority remains keeping impaired drivers off the road, regardless of the substance involved.
——
Eddie Celaya is a multimedia journalist at KGUN 9. Born in Tucson and raised in the Phoenix area, Eddie is a life-long Arizonan and graduate of the University of Arizona who loves the desert and mountains and hates the cold. Previously, Eddie worked in print media at the Arizona Daily Star. Share your story ideas with Eddie at edward.celaya@kgun9.com, or by connecting on Facebook or Instagram.
