Medical marijuana is beginning to be accepted in more and more states. Not in Tennessee. In some states even recreational use of marijuana is now allowed. Not in Tennessee. If you are stopped and are suspected of driving impaired by marijuana, you could be arrested and charged.
The movement toward legalization of marijuana means that in some states, authorities are being challenged to come up with ways to medically prove that drivers charged with driving while under the influence of marijuana were actually impaired at the time of the arrest.
It’s not an easy thing to do. Breath and blood tests have been developed for establishing for alcohol content and they have come to be widely accepted in the courts as evidence of impairment. That can make it hard, but not necessarily impossible, to challenge test results for alcohol in court.
Marijuana impairment is another story, however. It’s widely understood that while the body flushes alcohol out of the body relatively quickly, traces of the substance in marijuana that causes impairment can stay in the system for weeks. But detecting actual impairment is hard to nail down.
And it is in light of that reality that the Supreme Court of Arizona recently ruled that drivers under the influence of legal medical marijuana may be able to present an affirmative defense and thus avoid conviction for drugged driving.
What the court said is that just having marijuana in your system is not proof of impairment and if suspects can prove they weren’t affected enough to be considered impaired, they may be able to avoid a conviction.
Prosecutors aren’t happy with the decision, but the decision notes that it’s the result of dueling laws. On one hand, the impaired driving law in the state clearly states that a positive test for marijuana means a driver is guilty. On the other, the medical marijuana law says patients with prescriptions can’t be considered under the influence if the substances in their body aren’t in sufficient concentration to cause impairment.
Source: Arizona Daily Sun, “Arizona Supreme Court: Marijuana DWIs require proof of impairment,” Howard Fischer, Capitol Media Services, Nov. 20, 2015