DUI and marijuana, how does law enforcement know you're stoned while driving?
THC usage has increased since the passage of state laws allowing the use and possession of marijuana for recreational and medicinal purposes. This has a direct impact on DUI enforcement since more drivers will likely get stopped and arrested for suspicion of driving while high, or DUI-D. Some states like Washington and Colorado have passed laws setting a legal limit on THC levels. Both states have a limit of 5 ng/mL at which the driver is legally presumed "impaired" under the statute. Kansas has no such law but a driver can still be prosecuted for DUI-D if other factors are present during the testing stage of the investigation. A blood draw is required to test for THC and getting driver's to consent to a blood draw has proven difficult.
