Imagine that your friend “George” has cancer and got a medical marijuana card, and he utilizes the card as intended by his treating physician.  He’s extremely cautious about when and how he ingests marijuana because he knows that it can affect his ability to drive and perform certain tasks.  If he smoked marijuana, he always waited at least 24 hours before driving even though he knows that the effects usually wear off within about 3 or 4 hours. Under the circumstances, that sounds pretty responsible, right?

What Arizona’s DUI Law Was

Until earlier this week, even though George took precautions and had no impairing metabolite in his system, he could have been charged with a DUI. It works like this: once introduced into the body, the chemical compounds in marijuana begin breaking down into metabolites, and those metabolites show up in the bloodstream. The law, as it is written pertaining to DUI-drug charges, merely states that it is illegal to drive while there is any drug that is listed in the statutes or “its metabolite in the person’s body.”  

Marijuana contains THC, the chemical compound responsible for the psychoactive effects associated with marijuana use. THC first breaks down into a metabolite known as “Hydroxy-THC,” considered an active metabolite present in the bloodstream for a few hours while a person is still feeling the effects.

This compound is further broken down into Carboxy-THC, an inactive metabolite that can be present in the body for an extended period of time (anywhere from days to nearly a month, depending on the dosage).

Arizona’s New DUI Ruling

The Arizona Supreme Court issued its ruling this week, State v. Harris (Shilgevorkyan), CV-13-0056 6, ¶15 (Ariz. 2014), that the law should not be interpreted to mean that it is illegal to drive if a person has any metabolite in his or her system; it should be illegal only when that metabolite has been scientifically accepted to be an impairing metabolite, thus rendering the person “impaired to the slightest degree.”

Simply put, a person’s blood sample must indicate the presence of active drugs or active metabolites that have impairing abilities.  In the case of marijuana, that means a blood sample needs to contain THC or Hydroxy-THC (likely, at detectible levels).

So isn’t that what we all thought the law was?  Perhaps, but that’s not necessarily the meaning of the law as it was written in A.R.S. 28-1381A3.  If you read this statute carefully, you’ll see that there is no distinction between active metabolites and inactive metabolites.

For this reason, someone could still be charged with a DUI for smoking a marijuana cigarette four days prior to driving.

Realizing how unreasonable this was, the court posed a hypothetical situation to the State: “if a metabolite could be detected five years after ingesting a proscribed drug, a driver who tested positive for trace elements of a non-impairing substance could be prosecuted”? (State v. Harris (Shilgevorkyan), CV-13-0056 6, ¶15 (Ariz. 2014)).

How the Change Could Affect You

The State, using a very literal understanding of the written statute, said yes. The court did not agree with this theory and noted that the State’s interpretation of the law “would criminalize otherwise legal conduct.”

 In the case of George, he legally obtained his medical marijuana card and used the medication as prescribed. Imagine that you had surgery, and while in the hospital, were administered morphine.  If the inactive metabolites of morphine could appear in the bloodstream for six months, would it really be fair to give you a DUI even though you fully recovered two months ago?  Undoubtedly, the answer is no.

This ruling will likely create some waves in the law enforcement community, but it seems to be a very just decision. The reasoning behind our DUI laws is to protect those people on the road—and this will assist in doing that but will also prevent charging and convicting those individuals who are responsibly using prescribed medication, and not endangering others.