Arizona Court of Appeals: Medical Marijuana Authorization Not Sufficient to Overcome DUI Charge

Qualified Medical Marijuana Users Remain at Risk of DUI Prosecution.

Authorized Medical Marijuana users in Arizona have legal authorization to use the substance, but could still be charged with DUI if considered driving under the influence of drugs, according to a recent Arizona Court of Appeals ruling.

The court ruled Tuesday in the case of Darrah v. Hon. McClennen/City of Mesa, that Arizona Medical Marijuana Act does not protect users from prosecution if there is an active marijuana metabolite or chemical compound in the body when the users get behind the wheel.

Arizona voters approved medical marijuana November 2010. The state law allows people with doctor approval to apply for a medical marijuana card. Patients must have at least one qualifying condition, such as cancer or glaucoma, to legally receive the substance.

The driver in Darrah v. Hon. McClennen/City of Mesa was an authorized medical marijuana user. He was charged with two counts of DUI in violation of Arizona Revised Statutes § 28-1381.

The Arizona law states it is illegal for any driver in Arizona to drive or be in actual physical control of a vehicle while under the influence of intoxicating liquor, any drug or the combination of any liquor or drug if the person is “impaired to the slightest degree.”

This means if a person who legally uses marijuana or ingests cannabis, and then is stopped while driving a vehicle, he or she could be charged with DUI.

This could be compared to the use of prescription drugs. A person who was injured could have a valid prescription for Vicodin, but if he or she took the substance and decided to drive, that person could be considered impaired, resulting in DUI charges.

The driver in the case submitted to a chemical test after the arrest. The test, according to the ruling, revealed his blood contained 4.0 ng/ml of delta-9-tetrahydrocannabinol, also known as THC.  THC is an active component of marijuana.

A jury acquitted the driver of one DUI charge which alleged he was under the influence of a drug. However, he was found guilty of one DUI under Arizona Revised Statutes § 28-1381(A)(3), which says a person cannot drive or be in actual physical control of a vehicle with any drug or its metabolite in his or her body. On appeal, the superior court affirmed.

The detection time for marijuana metabolites can vary based on several different factors. Frequency of marijuana use, timing of the test and body fat content all could affect the levels of THC in the blood and impairment.

In the cases of habitual or frequent users, such as those authorized for medical marijuana, THC can remain in the bloodstream and may be detectable for days after a single use, or weeks in chronic users.

The driver argued he was wrongfully charged and cited another Arizona statute that says, “Operating, navigating or being in actual physical control of any motor vehicle, aircraft or motorboat while under the influence of marijuana, except that a registered qualifying patient shall not be considered to be under the influence of marijuana solely because of the presence of metabolites or components of marijuana that appear in insufficient concentration to cause impairment.”

The court, however, disagreed. Judge Michael J. Brown wrote in his opinion that nothing in the voter-approved law supported the defendant’s claim. Arizona voters had not approved the law with the intent to bar the State from prosecuting authorized marijuana users, the judge wrote.

This case is critical when it comes to medical marijuana users and their right to get behind the wheel in Arizona. The rulings do not set any definite limits for how much marijuana has to be in a driver’s system before he or she would face DUI charges.

Discussion and Impact of the Ruling in Arizona

The Justices cited contrasting opinions as to the basis of their decision.  But in the end, they concurred that the conviction should stand.   The impact is that Qualified Medical Marijuana users are not  immune from Drug DUI prosecution and convictions, solely due to the fact that they are authorized users.

In the ruling the court cited a recent Supreme Court case which held that “non-impairing” metabolite of marijuana is not a “proscribed drug” listed in A.R.S. § 13-3401 and therefore, the mere presence of a trace substance in a person’s blood stream does not  support a DUI conviction.   But this case had differences, for one, an active Marijuana compound,  THC, was present in the defendant’s blood stream.

The defendant argued that the Marijuana DUI should be set aside because of the Medical Marijuana language in A.R.S.  § 36-2802(D) that serves as an exception to DUI prosecution when the sole presence of metabolites of marijuana exist that “appear in insufficient concentration to cause impairment.” 

Notably one Justice agreed that the exception applied in this case. However, the Justice opinioned that the defendant failed to show that the amount of THC found in his system was not sufficient to cause impairment.   The prosecution on the other hand, provided expert testimony to the fact that 4.0 ng/ml (nanograms per milliliter) could possibly cause impairment, based on some studies.

In several states where Marijuana has been legalized in some form, statues exists which all for a qualified user to driver with a specified amount in their system for example 5 ng/ml.  An amount  found that exceeds the specified limit, in the driver’s bloodstream will result in arrest and prosecution.

In contrast, Arizona laws to not specify an amount that is allowable for drivers; only that it must be an amount sufficient to cause impairment.

Consequently, unless the law changes, or there is a scientific and medical consensus that establishes an undisputed quantity that results in impairment,  this will continue to be an issue for the courts to decide in Arizona.   Litigation will likely continue in this area, and be determined on a case by case basis, and weighted heavily on the evidence presented in those cases.