1,000 DUIs in SF Tainted by Cops' Negligence?

San Francisco police routinely mishandled a device used in field sobriety tests -- mistakes that may get as many as 1,000 DUI convictions overturned, the city's public defender said.

Police failed to conduct "accuracy checks" on a device called the Alco-Sensor IV, used to measure blood-alcohol levels, Bay City News reports. Officers should have performed accuracy checks -- to ensure the device was correctly calibrated -- every 10 days, according to the manufacturer.

The police mistakes appear to be "negligence as opposed to criminal conduct," San Francisco's district attorney said, according to the San Francisco Chronicle.

The DA and the public defender held a joint news conference Monday to address the San Francisco police DUI issue, first raised by attorneys with the public defender's office in January. They noticed police logs of accuracy checks showed the Alco-Sensor IV devices as being correctly calibrated, with the same exact reading, every single time.

"It would be mathematically impossible for that to occur," the public defender said. "The results ... plainly show that the accuracy testing was not being done."

The public defender and DA's offices are now working to identify DUI cases and convictions that may be affected by officers' failure to perform accuracy checks, the Chronicle reports. About 500 to 1,000 DUI convictions, dating back to 2006, may be overturned, the public defender said.

But not all DUI cases are in question -- only cases that relied heavily on Alco-Sensor IV test results to build a conviction are in dispute. The field-testing device is just one part of a DUI case; DUI suspects must take a separate test to confirm their blood-alcohol levels when taken into custody, and those tests are not being questioned.

San Francisco police stopped using the Alco-Sensor IV last month. Anyone who believes his or her DUI case may be affected should contact San Francisco's public defender's office, or the attorney who handled the case.

Related Resources:

• 'Negligent' Work Calls San Francisco DUI Convictions Into Question (Bay City News Service)
• Hundreds of DUI cases in S.F. could be tossed (San Francisco Chronicle)
• Browse DUI / DWI Lawyers by Location (FindLaw)
• NJ Cop Got Drunk to Teach Police DWI Class, Then Got a DWI (FindLaw's Legally Weird)