(CN) - A medical marijuana cardholder can use their card as a DUI defense, the Arizona Supreme Court ruled Friday, but two petitioners did not prove they were not too high to drive.
While it upheld Kristina Dobson and Marvelle Anderson's driving under the influence convictions, Arizona's high court said that a medical marijuana card may be used as an affirmative defense against DUI charges.
Defense attorney John Tatz told Courthouse News that Friday's ruling is "a good thing for medical marijuana cardholders going forward. At least they do have a defense to the DUI charges."
"Neither side walked away completely happy, but on balance we're happy with the result," amicus counsel Thomas Dean, representing the National Organization for the Reform of Marijuana Laws, told Courthouse News.
The Arizona Medical Marijuana Act, or AMMA, was passed in 2010, and allows a qualifying person to apply for a medical marijuana card authorizing them to possess and use limited amounts of marijuana as a pain reliever.
The AMMA immunizes cardholders from criminal prosecution for marijuana possession.
Arizona law, however, identifies two separate DUI offenses. The first criminalizes driving "while under the influence of any drug ... if the person is impaired to the slightest degree," known as an A1 charge.
The other, known as an A3 charge, criminalizes driving while there is marijuana or its metabolite, THC, in the person's body.
Dobson and Anderson sued after they were charged with driving under the influence and were prohibited at trial from showing that they held a medical marijuana card. Dobson's card was issued in Oregon, while Anderson holds an Arizona-issued medical marijuana card, court records show.
They claim that the AMMA immunizes them from prosecution based on the mere presence of THC in their system, without any proof of impairment.
Dean told Courthouse News that "active THC metabolites are detectable in the system for four days or more after using marijuana, long after the person is actually intoxicated."
The Arizona Supreme Court ruled Friday that a cardholder is not immune from prosecution for driving with THC in their body, but they may use their card as an affirmative defense if the marijuana in their system was "in a concentration insufficient to cause impairment."
"Possession of a registry card creates a presumption that a qualifying patient is engaged in the use of marijuana pursuant to the AMMA, so long as the patient does not possess more than the permitted quantity of marijuana," Chief Justice Scott Bales wrote.
But the state's high court rejected Dobson and Anderson's contention that medical marijuana cardholders should be granted the same defense afforded for the use of prescription drugs.
"Medical marijuana used pursuant to 'written certifications' under the AMMA is not 'prescribed,'" Bales wrote.
The court also placed the burden on plaintiffs to show they did not have marijuana concentrations sufficient to cause impairment.
Dobson and Anderson argued that this was unfair, given that there is no accepted threshold for marijuana impairment, unlike alcohol.
But the Arizona Supreme Court was not persuaded.
"The risk of uncertainty in this regard should fall on the patients, who generally know or should know if they are impaired and can control when they drive, rather than on the members of the public whom they encounter on our streets," Bales said.
Since neither Dobson nor Anderson presented any evidence that the marijuana in their bodies was insufficient to cause impairment, Arizona's high court affirmed their convictions.
"Any error by the trial court in excluding evidence of the registry cards was harmless in light of the stipulations by petitioners that they had marijuana in their bodies while driving (blood tests revealed both THC and its impairing metabolite hydroxy-THC) and their failure to offer any evidence that the concentrations were insufficient to cause impairment," the eight-page ruling concluded.
Dean said of the ruling, "Of course we wanted the court to agree with us that the medical marijuana privilege in question provided complete immunity to the A3 DUI per se charge. Such charges are based solely on what's found in the driver's blood."
He noted that it will be difficult for cardholders charged with a DUI to prove they were not impaired.
"You'll be hard-pressed to find an expert scientific witness who will say that any particular level is incapable of causing impairment because marijuana effects people so differently," Dean said. "Two nanograms may affect one person, but twenty nanograms may not affect another."
He continued, "So it almost opens the door for jury nullification where the jury says, well if the guy's not impaired how can THC metabolites have caused impairment?"
Dean said that a National Highway Traffic Safety Administration study found no correlation between driving fatalities and marijuana use.
Arizonans for Mindful Regulation supports two proposed ballot initiatives for 2016, including the Regulate Marijuana Like Alcohol Initiative.
"So if that passes, this decision will be moot for adults over 21 who will all be immune from prosecution under A3," Dean said.