The implementation of Arizona’s medicinal marijuana use law has seen plenty of controversy. Since the law was approved by voters in 2010, state and county authorities have resisted it in court; most notably by saying that they would be in violation of federal law, which still lists marijuana as an illegal substance.
The debate over marijuana use became much more complicated after the Arizona Court of Appeals ruled that drivers could be prosecuted for driving under the influence of the drug, even though there was no evidence that they were impaired at the time of arrest. Essentially, the court ruled that as long as there is evidence of THC in a person’s system (obtained through blood or urine tests after a drunk driving arrest) a driver could be charged with marijuana DUI.
The ruling focused on the chemical compounds that are found through such tests, which may reveal a component that causes drivers to be impaired, as well as another that has no effect on impairment. It is this component that stays in a person’s system, even though it does not affect their motor functions.
The case stems from a case (coincidentally in 2010) where a driver was charged with marijuana DUI after a blood test revealed the inactive compound indicating that he had used marijuana, but was not necessarily impaired. The trial court had previously dismissed the case, ruling that it was improper to prosecute a driver for DUI when there is no evidence of impairment.
The impaired also complicates the debate over accurate testing methods, which legislatures in neighboring states (particularly Colorado) have struggled with. It is expected that the Arizona Supreme Court will hear the case.
Source: AZfamily.com, Arizona court ruling upholds DUI test for marijuana, February 18, 2013