MSP Lab Stops THC Blood Tests Amid Accuracy Concerns

The Michigan State Police Crime Lab notified prosecutors across the state that it is halting the processing of THC blood samples due to accuracy concerns on August 25, according to an MLive article. MLive received an email from the MSP Forensic Science Division stating, “Out of an abundance of caution (MSP) today notified the Prosecuting Attorney’s Association of Michigan that we are immediately halting the processing of all THC blood samples as we work to learn more and/or until we can institute another validated method of testing to ensure accuracy.” The problem, according to the article, is that the current toxicology test confuses CBD (does not induce a high) with THC, the psychoactive ingredient in marijuana. The discrepancy led to a test result that identified CDB as THC earlier in the week.

PAAM Executive Director Cheri L. Bruinsma emailed state prosecutors advising, “[The MSP Crime Lab] very recently learned that the test is unable to distinguish between THC and CBD. They are working to understand the issue and scope of the problem. They expect to have additional information in the next few weeks. In the meantime, if you have a case that relies on a THC toxicology screening, you should not rely on that result.” Jackson County Prosecutor Jerry Jarzynka notified judges and attorneys in the county that, during the testing halt, his office “will not be able to rely on MSP Crime Lab THC toxicology screening.” Wayne County Prosecutor Kym Worthy stated, “It is important for everyone that could possibly be affected by this to be informed.” Attorney Michael Komorn told MLive that the test accuracy issue could call thousands of convictions across the state into question depending on how long the problem has persisted.

Find the MLive article at

by John Zevalking
Associate Editor