Dobson v. McClennen (Mesa Prosecutor) – 11/4/2015

December 9, 2015

Arizona Supreme Court holds that the Arizona Medical Marijuana Act provides an affirmative defense but not immunity against prosecution under the DUI statute A.R.S. § 28-1381(A)(3).

Petitioners were convicted of DUI under A.R.S. § 28-1381(A)(3), which prohibits driving if a person has any amount of marijuana or other defined drugs in that person’s body.  Petitioners had attempted to present their medical marijuana cards as a defense.  The superior court and court of appeals upheld the convictions.  The Supreme Court granted review of whether the Arizona Medical Marijuana Act immunizes a medical marijuana cardholder from DUI prosecution under § 28-1381(A)(3).

The Arizona Medical Marijuana Act grants broad but not absolute immunity for the authorized medical use of marijuana.  It does not prohibit DUI prosecutions but provides that a qualifying patient is not considered under the influence if the concentration of marijuana is insufficient to cause impairment.  A.R.S. § 36-2802(D).  A medical marijuana user also cannot rely on the DUI defense that the drugs were prescribed by a licensed medical practitioner because medical marijuana is not “prescribed” and the class of licensed “medical providers” is different.  Although A.R.S. § 28-1381(A)(3) indicates that a person with any amount of marijuana is guilty of the offense, a medical marijuana patient facing an (A)(3) violation may establish an affirmative defense by showing that the marijuana use was authorized under the statute and that the marijuana or its metabolite was in a concentration insufficient to cause impairment.  Despite petitioners’ argument that there is no commonly accepted concentration threshold for impairment, the Court placed the burden on the patient to prove a lack of impairment by a preponderance of the evidence.

Chief Justice Bales authored the opinion; Vice Chief Justice Pelander and Justices Brutinel, Timmer, and Berch (retired) joined.