Arizona Supreme Court limits DUI for residual marijuana test

Since medical marijuana was legalized in Arizona in 2010 questions have arisen about what should actually be defined as impairment under the influence of the drug.  Last year, the Arizona Court of Appeals held that motorists can be prosecuted for DUI when there is evidence of marijuana in the system even when impairment cannot be proven.  Recently, the Arizona Supreme Court overturned that ruling, finding that a person may only be prosecuted if impaired when stopped. The ruling follows a trend in other states that have also required signs of impairment.

In the case heard by the courts a man who had smoked medical marijuana the night before being stopped for speeding was charged with DUI. Blood tests showed that the form of marijuana detected in his system at the time of the stop was not the kind that causes impairment. The Supreme Court found that the interpretation of the law that led to a DUI charge whether or not a driver was impaired was “absurd” by creating criminal liability for drivers who are not truly impaired.

The fine line addressed by the ruling involves two different compounds that are measured in blood and urine tests after marijuana use. One actually measures impairment while the other is not indicative of impairment but still remains in the system of the user for weeks after using the drug. Those who opposed the current law argued that it limits the legalization of the drug by effectively revoking the driving privilege of those who legally use the drug for weeks after using it.

The case is an excellent example of how someone charged with DUI may not always be impaired under the definition of the law. Tests used to measure impairment are not always correct either due to a problem with the test itself or a mistake by the person who administers the test.

As in this case, there may be mitigating factors including the residual effects of certain substances even when the driver is not legally impaired. Anyone who has been charged with a DUI in Arizona should consult an experienced DUI attorney who may be able to have charges with potential consequences or even a jail sentence reduced or dismissed.

Source: Huffington Post, “Arizona Court Overturns Marijuana DUI Ruling,” Brian Skoloff, April 22, 2014