Michigan drivers can no longer be convicted for the simple presence of THC byproducts in their bodies after smoking marijuana. The Michigan Supreme Court's liberal majority ruled Tuesday that it is not illegal to drive while having marijuana byproducts internally.
Until Tuesday's ruling, if you smoked a joint over the weekend and then got drug tested on Monday morning -- or even a month later -- you could be convicted of "Driving Under the Influence of Drugs" (DUID), even if you are no longer high, just because inactive chemical traces of THC remain in your bloodstream.
According to the court, 11-carboxy-THC, a metabolite of tetrahydrocannabinol, one of the main active ingredients in marijuana, cannot be considered a controlled substance under Michigan law, according to The Associated Press.
The justices ruled that 11-carboxy-THC is a byproduct created when the body breaks down (metabolizes) THC.
The court had ruled differently in 2006, when it had a conservative majority and faced the same issue in another case.
According to the court in that consolidated case, Derror v. Michigan and Kurts v. Michigan, actual innocence of driving while impaired was "irrelevant."
In both those cases, police charged the defendants under the Michigan DUID law based on the presence of marijuana metabolites, inert by-products of the body's breakdown of THC, in their blood.
The presence of cannabis metabolites does not mean a person is impaired or under the influence of marijuana; it just indicates that the individual ingested THC at some time in the past 30 days or so.
From the time of that ruling in 2006 until Tuesday's decision, any Michigan driver who had smoked pot in the past few days, or in the case of heavier smokers, in the past month or so, was subject to a DUID arrest based on the presence of the metabolites, which do not actually indicate impairment.