Tuesday, April 22, 2014
Arizona Supreme Court holds driving with trace amounts of marijuana in the blood is not enough for a DUI conviction
The Arizona Supreme Court issued a decision today on marijuana and driving under the influence (hat tip to Elizabeth Joh for passing along the news).
As most readers probably know, marijuana stays in a person's system long after they use it. As a result, a positive blood test for marijuana doesn't mean they person is impaired at the time of the test. Because there is currently no blood or breath (or spit or sweat, etc.) test to accurately measure marijuana impairment the way we do for alcohol, states have struggled over the legal standard for marijuana impairment.
This is a problem that goes far beyond marijuana (it exists for all legal prescription medications, for example) and, I think, is only tangentially related to marijuana legalization (after all, plenty of people use marijuana illegally so marijuana and driving is a concern regardless of its legal status.) Nevertheless, medical marijuana and legalization laws have shined a bit of a spotlight on the issue.
One particularly controversial approach to the issue is to say that driving with any traces of marijuana in the blood is sufficient evidence for a DUI conviction. Today's decision from Arizona's Supreme Court disapproves of this practice. Unfortunately, the opinion page on the Court website is not loading so I haven't yet been able take a look at the decision and am unable to provide a link at the moment (update: the Supreme Court site is working again, opinion (PDF) is here).
For now, this article has a good summary:
The case before the case involves a driver cited for a traffic violation who, when given a blood test, was found to have Carboxy-THC in his system and was charged with driving with an illegal drug or its metabolite in his body.
A trial judge threw out the charge, but the Court of Appeals said the laws on impaired driving “must be interpreted broadly.”
In arguments to the court, Susan Luder, a deputy Maricopa County attorney, acknowledged that Carboxy-THC, a secondary metabolite of marijuana, can show up in blood tests for a month after someone has used the drug. She did not dispute the concession of her own expert witness that the presence of that metabolite does not indicate someone is impaired.
But Luder told the justices the Legislature is legally entitled to declare that a positive blood test for Carboxy-THC can be used to prosecute someone who, if convicted, can lose a driver's license for a year.
Justice Robert Brutinel, writing the majority ruling, said that argument makes no sense.
“This interpretation would create criminal liability regardless of how long the metabolite remains in the driver's system or whether it has any impairing effect,” he wrote. Brutinel pointed out that Lunder admitted to the justices that, the way Arizona law is worded, “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.”
Update: Now that the opinion is up, the precise question addressed by the Court may frame the issue it decided a bit better than the above. This is the first paragraph from the opinion linked above:
Arizona Revised Statutes § 28-1381(A)(3) makes it unlawful for a driver to be in actual physical control of a vehicle if there is “any drug defined in [A.R.S.] § 13-3401 or its metabolite in the person’s body.” We are asked to determine whether the phrase “its metabolite” includes Carboxy-Tetrahydrocannabinol (“Carboxy-THC”), a non-impairing metabolite of Cannabis,1 a proscribed drug listed in § 13-3401. We conclude that it does not.