As part of a robust quality assurance program, the San Mateo County Sheriff’s Office Forensic Laboratory routinely tests samples prepared by independent, outside agencies to verify that in-house equipment and test procedures are consistent with other forensic laboratories in the state.
These verification tests occur multiples times a year. Recently, data suggested items tested on an external blood alcohol analysis proficiency test completed in October 2021 were slightly higher than the mean of other California laboratories that also participated in this test. The California Department of Public Health deemed the results to be outside the acceptable range—with the mean of the results being 0.002 to 0.006% higher than what is acceptable.
The laboratory has confirmed that the instrumentation and reagents are working properly now, and are currently retesting samples to determine the scope of affected tests. As of now, the scope appears to be between 100 to 250 samples tested between Sept. 1, 2021 and Nov. 2, 2021.
These blood alcohol test results are often used as evidence in legal proceedings, such as DUI cases. In the review of the cases that have been adjudicated in court, San Mateo County Sheriff’s Office Forensic Laboratory has, thus far, not located any samples near the legal limit of 0.08% blood alcohol content that would have been affected by the anomalous range detected in this review.
The laboratory has notified the San Mateo County District Attorney’s Office and will continue to work with them to evaluate the impact, if any, on affected criminal cases.
Republished courtesy of San Mateo County Sheriff’s Office.