Discrepancy in MSP's marijuana testing may impact more than 3,200 cases in Michigan
(CBS DETROIT) - Some cases related to alleged marijuana impairment could have been false positives after Michigan State Police detected possible discrepancies in 3,250 laboratory reports.
State police halted testing after it was determined that samples containing CBD may have converted to THC during the process.
In a statement on Wednesday, Col. Joe Gasper says the cases on or after March 28, 2019, (the day CBD became legal in Michigan) have an "alleged violation is based on the finding of THC alone and there is insufficient evidence of impairment, intoxication, or recent use of marijuana to otherwise support the charged offense."
Officials say the laboratory reports included THC-confirmed results "without other drugs present or alcohol detected above the 0.08% blood alcohol content legal threshold."
MSP was first notified of the issue on Aug. 19. Further evaluation indicated that the laboratory method may cause THC to be identified when the sample contains CBD alone as well as when the sample contains both THC and CBD.
On Aug. 25, authorities alerted the Prosecuting Attorneys Association of Michigan and notify prosecutors to avoid using the reports in any current or pending court cases.
Officials say individual cases will be reviewed by prosecuting attorneys to determine if there was any impact.
In addition to halting the tests, tMSP's Forensic Science Division has taken the following action steps:
- Reported the issue to our accrediting body, ANSI National Accreditation Board (ANAB), and requested they conduct an independent review.
- Temporarily halted the disposal of blood samples to preserve this evidence should re-analysis be required.
- Started validating a new cannabinoid confirmatory method that will be able to distinguish CBD from THC. This method will be validated before being put into use to ensure similar issues with drug interference will not happen in the future.
- Started the process to establish a contract with a private, accredited laboratory for processing THC samples in the interim before the new method is validated.
