Defective Urine Tests From Santa Rosa Lab May Have Led to Some False DUI Positives

"the Bureau of Forensic Services, provided a list of 14 tests that were conducted using the defective kits, though five were tied to investigations that did not result in charges. Per the Chronicle, prosecutors said they notified defense attorneys this week after identifying the affected convictions. The District Attorney's Office identified nine convictions that utilized the tests primarily DUI cases, after the lab reported that some kits from supplier Andwin Scientific contained an incorrect concentration of sodium fluoride, about 100 milligrams instead of the stated 750 milligrams."

"This could allow yeast and sugar to ferment, potentially producing inaccurate alcohol readings and may result in an artificially elevated alcohol level in the sample, said lab director Katina Repp in a January 28 letter. Repp said inaccurate alcohol readings would likely occur only in samples with enough sugar and yeast to trigger fermentation, which can happen in people with certain health conditions or infections."

"She said the lab stopped shipping the affected kits and notified the supplier after discovering the issue in August 2025, noting that kits distributed since September should contain the correct concentration. It is impossible to assess whether samples taken during investigations of criminal matters"

The Bureau of Forensic Services in Santa Rosa issued defective urine test kits supplied by Andwin Scientific that contained approximately 100 milligrams of sodium fluoride instead of the required 750 milligrams. This deficiency allowed yeast and sugar to ferment in samples, potentially producing artificially elevated alcohol readings. The lab identified 14 tests conducted with faulty kits between 2016 and 2025, resulting in nine convictions primarily in DUI cases. Inaccurate readings would likely occur only in samples with sufficient sugar and yeast to trigger fermentation, which can occur in individuals with certain health conditions or infections. The lab discontinued shipping affected kits and notified the supplier after discovering the issue in August 2025. It remains unclear whether other California counties received and used the defective kits.

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