Court Rules Marijuana Users Must Show Impairment to Face DUI Penalties

The Arizona Court of Appeals recently ruled that the state cannot suspend a driver’s license due to the presence of THC in their bloodstream unless the driver is actually impaired at the time of driving. This decision upholds a provision of the marijuana legalization law that was passed by voters in 2020.

The case involved Aaron Kirsten, who was pulled over for speeding in Sedona in October 2022. Observations by the police officer noted Kirsten’s bloodshot eyes, slurred speech, and unsteady gait. Although he refused a field sobriety test, a breathalyzer indicated a blood alcohol concentration of 0.083, slightly above the legal limit, leading to his arrest.

In custody, Kirsten agreed to a blood draw. The analysis revealed a blood alcohol content of only 0.063, below the state’s threshold. However, the Department of Public Safety tested for drugs and detected THC metabolites, which prompted the Arizona Department of Transportation to suspend his license for 90 days based on a law prohibiting driving with THC metabolites in the system.

During an administrative appeal, Kirsten testified he had not consumed THC within the 24 hours before his arrest. A witness, a family member with a medical background, supported claims that THC metabolites can remain detectable for weeks post-consumption. Despite this, the administrative law judge ruled that it was irrelevant whether Kirsten had recently consumed THC, siding with ADOT’s decision.

Kirsten subsequently appealed to the Maricopa County Superior Court, which upheld the administrative ruling. However, the appellate court found that both lower courts misapplied voter-approved laws that protect drivers from penalties solely due to past marijuana use, provided they are not impaired while driving.

The court noted that Arizona law specifically protects the rights and privileges related to legal marijuana use. Driving privileges, according to the court, cannot be revoked simply due to the presence of THC metabolites. Additionally, Proposition 207 explicitly allows for penalties only in cases of driving “while impaired to even the slightest degree.”

This interpretation clarifies that a driver can only be penalized under the previous law concerning THC metabolites if they are also found to be impaired. The unanimous three-judge panel emphasized that the intent of Proposition 207 ensures that unimpaired drivers cannot be penalized for legal marijuana consumption.

In a further victory for Kirsten, the appellate court dismissed the state’s argument to uphold the suspension based on alleged alcohol impairment, highlighting that the state had not pursued this claim effectively.