Court Rules Medical Marijuana Users Cannot Be Convicted of DUI in Arizona     

In December 2016, the Arizona Court of Appeals ruled that the courts cannot convict medical marijuana users of driving under the influence (DUI) without proof of actual impairment. This was a major step forward for marijuana patients in the state, who had previously faced the burden of having to prove they were not impaired to defend against a DUI conviction. Learn what the ruling has meant for patients in Arizona in the year since.

Old and New Marijuana DUI Laws in Arizona

Since the passing of the Arizona Medical Marijuana Act in 2010, there have been confusing gray areas in marijuana-related DUI laws. A driver with any amount of marijuana in his or her system is guilty of DUI if the driver does not have a valid medical marijuana card with the Registry. If, however, the driver has a card and can legally possess and use marijuana, the legality of a DUI is questionable.

Before the court ruling, an officer could arrest an individual for marijuana-related DUI, regardless of the question of impairment. This meant that a patient legally using marijuana could face jail time, fines, and other penalties for driving, even if he or she used days ago and was not at all impaired at the time of arrest. If blood tests showed levels of marijuana’s active ingredient, THC, the driver could receive a DUI conviction if the driver could not prove that he/she wasn’t impaired.

After the 2016 ruling, it is no longer legal to convict someone of marijuana-related DUI without the prosecution showing proof of impairment. Judge Diane Johnsen wrote that, since there is no scientific consensus about the level of THC that causes impairment, there is no way for law enforcement to base DUI charges on THC levels alone. It is also not up to the driver to prove his or her innocence. Instead, police bear the burden to prove the driver’s impairment beyond just blood test results.

Proving Marijuana Impairment

Judge Johnsen’s 2016 letter in the ruling said that nothing in Arizona’s statutes requires a medical marijuana cardholder to present expert testimony to prove he or she was not impaired due to THC. The ruling meant the burden of proof for marijuana-related DUI charges is now on Arizona police, not patients. Since then, police have had a difficult time proving impairment, due to the unique nature of THC.

No two patients are the same. Some people feel impaired after using a small amount of marijuana. Others can use a significant amount without impairment. This fact, and the ruling that THC is not enough to prove impairment has made it difficult for police to prove cannabis DUIs. Patients who receive DUI charges can now fight them, presenting evidence that the THC did not impair them at the time of the arrest.

The ruling was great news for Arizona’s patients, but it doesn’t mean it’s impossible to receive a DUI conviction for having marijuana in your system as a legal patient. If you’re facing a DUI charge for marijuana in Arizona, contact an attorney right away to begin your defense.