Oklahoma Gov. Mary Fallin has signed legislation, House Bill 1441, into law that criminalizes drivers from operating a motor vehicle if they have any detectable amount of THC and/or its inactive metabolites in their blood or urine. Under such internal possession statutes, known as zero tolerance per se laws, motorists who test positive for the presence of such compounds are guilty per se (in fact) of a criminal traffic safety violation, regardless of whether or not there exist supporting evidence that a defendant was behaviorally impaired by such compounds.