MSP Forensic Division Gives Update on THC Testing - December 2022

  In late August 2022, the Michigan State Police Forensic Science Division (MSP/FSD) announced that it was halting THC testing because the toxicology test potentially confused 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.

On November 14, 2022, the FSD announced that an upgraded THC testing system platform has been validated and was put in place on November 9, 2022. The new testing system, known as Liquid Chromatography with tandem Mass Spectrometry (LC-MS-MS), does not include the same mixing technique that led to the problems with the former platform, Gas Chromatography Mass Spectrometry (GC-MS).

To avoid a backlog during the offline period beginning in August, the FSD outsourced some 700 samples to an accredited private toxicology lab. The lab has returned 574 test samples so far. Among those samples, 238 were confirmed to contain THC, and two samples were found that confused CBD for THC, one of which was the case that initiated the inquiry.

For the sake of transparency, the FSD has made the 1,350-page LC-MS-MS validation summary with supporting data available for review at
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by John Zevalking
Associate Editor