Critical mistakes at a Santa Clara County crime lab went unnoticed for two months, and prosecutors are promising change, the Santa Clara County District Attorney's Office said.
The errors happened while testing for meth from January through March, according to the DA's office. The blood and urine test results came back positive when they should have been negative.
A criminalist discovered the error last month after noticing the test's sensitivity was set higher than it should be.
The person who made the mistake has now been reassigned.
The DA's office said all new samples will be double checked by a second analyst.