DETROIT (AP) — The Michigan State Police crime lab stopped screening blood samples for THC, the compound that gives marijuana users a high, after testing issues, said a spokeswoman.
County prosecutors were notified this week, Shanon Banner told The Associated Press.
The suspension will be in place “As we work to learn more and/or until we can institute another validated testing method to ensure accuracy,” Banner said in an email.
As of 2018, marijuana is legal under state law for people who are at least 21 years old. Medical use was approved 10 years earlier.
It is still illegal to drive under the influence of marijuana, but Michigan, unlike some other states, does not have a set limit. In 2019, a commission recommended not creating a threshold due to a “bad correlation” between bodily content and impaired driving.
Nonetheless, prosecutors can still present evidence of THC in court, defense attorney Mike Nichols said.
“Someone gets arrested and there is an accident where someone is injured or killed,” he said. “It’s been a big problem since we went into medicine in 2008. I’m getting more and more cases.”
Banner said a “divergence” in the lab was discovered this week in which the presence of CBD may have led to a positive result for THC.
CBD, also found in marijuana, does not cause a high and is often sold as a dietary supplement or included in creams and other personal care products. CBD products are legal, with some restrictions, in almost all states.
“We are actively working to identify the scope, but will likely not have additional information until next week,” Banner said.
Nichols thinks the problem lies with inadequate technology in the lab.
“There is a more sensitive methodology, but these instruments are much more expensive,” he said.