Authorities say the Orange County Crime Lab has mistakenly identified about 20 people as having illegal blood-alcohol levels.
The Orange County Register says a flawed test at the lab churned out inaccurate results for nearly five months.
Lab director Bruce Houlihan says a calibration error in a blood-testing machine threw off the result by .003 percentage points — enough to change a blood-alcohol level that's just below the .08 legal limit.
Houlihan says out of hundreds of drunk-driving cases, the error only affected about 20 defendants. The district attorney's office is trying to determine whether any of them have gone to trial or pleaded guilty.
However, the office also has notified 900 other people who were convicted or pleaded guilty that they may want to talk to an attorney.