Maricopa County, AZ- The Arizona Supreme Court decided in Tuesday that driver who has only a trace amount of marijuana in their system cannot be charged with driving under the influence. A decision which will likely be looked at by other states that have marijuana DUI laws similar to Arizona.

The high court’s ruling overturns a decision by a state Court of Appeals of which said prosecutors have the right to charge a person with driving under the influence even if they have small amounts That ruling meant that a person could be charged with marijuana-DUI even if they were not actually under the influence of the drug.

Prosecutors in the state had warned the 40,000 medical marijuana users in the state to avoid driving or face DUI charges. Pot activists took issue with the warning stating that the law criminalized behavior that Arizona voters said was legal in 2010 when they approved marijuana for medicinal use.

The case before the state Supreme Court centered on a man who was charged with DUI after police found Carboxy-THC in his system. He was charged with DUI under a state law which says it is illegal for a person to drive with any drug metabolites in their system.

A trial judge threw out the charges but the Court of Appeals said DUI laws should be interpreted broadly.

In their opinion, the Arizona Supreme Court focused on the compounds that are present in the marijuana users; one that makes them impaired, Hydroxy-THC, and another which is a metabolized byproduct Carboxy-THC.

The court’s decision contends that the drivers can test positive or Carboxy-THC weeks after the intoxicating psychoactive effects of marijuana have long worn off. Deputy Maricopa County attorney Susan Luder argued that under state law prosecutors are legally entitled to declare that a positive blood test for Carboxy-THC is enough to charge a person with DUI, but the court disagreed.

According to the Arizona Daily Sun, Justice Robert Brutinel, wrote in the majority ruling, “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 noted that even prosecutors admit that the presence of Carboxy-THC does not mean a driver is impaired.

There are 21 states where medical marijuana are legal but only eight of those states have laws similar to Arizona’s under which a person with either Carboxy-THC or Hydroxy-THC in their systems can be charged with DUI even though they are not impaired.

These laws have good intentions but there is a risk of people facing unnecessary criminal charges for something they did in the past. There are ways to avoid a being convicted for DUI-marijuana. A DUI attorney understands the science behind marijuana intoxication and will build a vigorous defense on their client’s behalf. With legal help, an offender has a better chance of avoiding conviction, having their charges reduced or negotiating for a plea bargain.