Hundreds of blood samples tested at the Orange County Crime Lab are now in question after officials found flaws in testing that produced inaccurate blood-alcohol readings for nearly five months beginning in late May.
"I'm appalled that the crime lab can let something like this go on for such an extended period of time. It's unacceptable," said "John," who was arrested for DUI. He did not want to be fully identified because his case is still pending.
John received a letter from the district attorney's office, as did 900 others who have already been convicted or pleaded guilty to driving under the influence.
"Those 900 were sent letters indicating there had been an error in the crime lab processing," said Orange County District Attorney's Office Spokesperson Farrah Emami.
The crime lab tests the same blood sample twice using two different machines, then averages the readings. The lab director says the error happened when the lab calibrated one of the machines and failed to input a data point in the software, throwing the machine off by .003 percentage points.
"Because of the size of the error we didn't actually notice it until we actually did an audit. Very, very small, about 200 cases will have their blood-alcohol average that will change," said OC Crime Lab Director Bruce Houlihan.
The crime lab says about 20 people had blood-alcohol levels incorrectly reported at .08 percent, when they should have been .07, below the legal limit.
"This is a lack of quality control. This is a forensic nightmare," said attorney Virginia Landry, a member of the California DUI Lawyers Association.
Landry says so far her firm is revisiting 30 cases because of the error.
"If there is a case where the defense attorney or the defendant feels that their case may be impacted, we can take a look at that," said Emami.
But the Orange County District Attorney's Office says because the error was so small, it doesn't expect it will change most of the cases.
Officials say that the corrected test results will be posted on the OC Crime Lab website by Dec. 1.
That's something "John's" attorney will be looking at closely, concerned an inaccurate higher reading could mean a harsher penalty for his client.