A district judge in Yellowstone County denied an attorney's challenge to the constitutionality of Montana's DUI law for marijuana.
Public defender Gregory Paskell argued that the 5 ng/mL blood content threshold that constitutes a DUI in Montana isn't supported as a scientific point of impairment.
Paskell represents Kent Roderick Jensen, 20, who was charged with vehicular homicide while under the influence after he crashed into a motorcycle in March 2016, killing the rider.
A blood test showed Jensen's blood contained 19 ng/mL of THC, the psychoactive compound in marijuana.
District Judge Gregory Todd denied Paskell's request for a constitutionality review of the DUI limit in an order filed on Monday. He concluded that the issue at hand is marijuana consumption, which is not a fundamental right under threat in this debate.
Todd said that while the science may not be precise on impairment, the goal of the law was to reduce impaired driving.
"Currently there may be no method for precisely measuring the distracting effects of THC on a person," Todd wrote in his order. "But it is scientifically proven that THC had major psychoactive effects on people, and driving while under its effects poses a major risk to the driver and the public."
Paskell was trying to have the charge against Jensen dismissed. He cited a 2016 report from the AAA Foundation for Traffic Safety that cast doubt on a specific level of THC impairment, because tolerance varies considerably between people. He called on a chemist from a Colorado pharmaceutical testing lab, who testified that he agreed with those claims.
Deputy Yellowstone County Attorney Victoria Callender, the prosecutor in the case, argued that the Legislature had relied on the determination of the Montana Crime Lab to set the 5 ng/mL, which was set by the 2013 Montana Legislature.
Todd's ruling reflected that argument. The constitutionality of the law was upheld in the Legislature's "responsibility to pass laws that provide for the general welfare, notwithstanding the absence of a perfect measuring method," he wrote.
Jensen's trial date is currently set for Aug. 30.