When a person uses marijuana, the high from the THC last for about two hours, but the THC metabolites are detectable in the person’s urine for up to five weeks. Suppose a person smokes marijuana and a week later is pulled over and investigated for DUI (called ‘OVI’ in Ohio). If that person submits a urine sample and the urine test shows a prohibited level of marijuana metabolite, that person will be prosecuted for OVI because it is ‘per se’ illegal to operate a vehicle with a prohibited concentration of marijuana metabolites, even if the person’s driving is not impaired. Challenges to this ‘per se’ OVI law have been unsuccessful in Ohio courts. A recent case from the Ohio Supreme Court suggests the Court may be inclined to evaluate the constitutionality of the OVI ‘per se’ law for drugs.