O.C. Crime Lab finds more errors in DUI testing

State officials are being asked to review the work of the Orange County Crime Lab after more errors were found in its blood-alcohol testing — mistakes that could potentially affect dozens of DUI cases.

The new discoveries come just weeks after the lab acknowledged inaccurate blood-alcohol test results in 2,200 driving-under-the-influence cases. Prosecutors responded by sending letters to drivers charged with DUIs, including 900 who already had been convicted.

Now, Sheriff Sandra Hutchens and the county Board of Supervisors have requested that the state department of health review the lab’s procedures and case standards and present the results to elected leaders, officials said.

“We are bringing in state health to take a look because we want to ensure public confidence in the system,” said Bruce Houlihan, lab director.

Houlihan said the latest problem was uncovered while conducting a five-year audit of the lab’s work in the aftermath of the initial error. Auditors, he said, discovered that a second machine at the lab had a calibration error that could produce blood-alcohol readings that were off by .001 of a percentage point. The faulty reading occurred between December 2012 and May 2013.

During that period, the lab examined about 7,000 samples with the instrument, and the calibration error affected about 1,000 of those tested. But because the blood alcohol in each case is tested on two separate instruments and then averaged, it’s estimated that only about one-tenth of those tests were affected, he said.

Houlihan said the blood-alcohol readings were underestimated in about 100 cases and will have to be corrected.

In nine of those cases, the blood-alcohol reading will actually increase from .07% to .08%, the level at which a person is considered legally drunk. That means new charges could be filed against drivers initially thought to have been legally sober.

“We will review any cases they provided to the office with new numbers,” said Farrah Emami, a spokeswoman for the Orange County district attorney’s office.

Virginia Landry, a defense attorney known as the “DUI Queen,” predicted the second error will call into question far more cases than the sheriff’s officials are letting on.

“This is adding to their problems,” she said. “We have a whole year’s worth of data that is wrong. If their science does not work, people are going to be wrongfully accused and convicted.”

Sentencing enhancement for drunk drivers could also be affected, since the punishment for drunken driving varies, depending on how far over the legal limit the driver is.

After the initial errors were discovered this month, prosecutors sent letters to people charged with DUIs and advised them that their cases were among those with miscalculations.

In those cases the machine had increased the blood-alcohol readings.

Crime lab officials blamed the earlier botched results on “human error” over a nearly five-month period.

But they insisted the miscalculations affected only about 200 cases. As few as 20 people could see their blood-alcohol test levels drop below .08% and have their cases potentially dismissed. One of the machines was off by.003 of a percentage point, he said.

Hutchens, however, stood by the lab’s work.

“I am confident that the Orange County Crime Lab is taking the necessary steps to insure that these clerical errors do not occur in the future,” she said in a statement.

richard.winton@latimes.com