Hundreds of DUI cases in S.F. could be tossed Screening device wasn't checked enough, D.A. says

Hundreds of drunken-driving convictions in San Francisco could be thrown out because of questions about how police handled the device that measures blood alcohol levels, prosecutors and the public defender's office said Monday.

The problem could affect as many as 1,000 convictions, said Public Defender Jeff Adachi, whose office is working with District Attorney George Gascón's prosecutors to identify guilty verdicts that may be in jeopardy.

At issue is how the Police Department conducted accuracy checks for preliminary alcohol screening devices, which officers in the field use to determine whether a drunken-driving suspect's blood alcohol level is above 0.08 percent, the legal limit for intoxication. Suspects exhale into the device to produce a reading.

The manufacturer of the Alco-Sensor IV devices says police should conduct accuracy checks every 10 days, or after 150 tests, by using the device to measure the alcohol level in a gas canister. The canister's alcohol level is always the same - 0.082 percent.

Suspicious readings

In January, several attorneys for the public defender's office noticed that in police logs on the accuracy tests dating back to 2010, the devices were listed as reading the canister gas exactly correct every time, Adachi said at a press conference Monday.

In practice, at least some devices' readings should have been incorrect, Adachi and Gascón said. When the readings are wrong, the machines have to be recalibrated so they produce accurate results.

"It would be mathematically impossible for that to occur," Adachi said of the consistently on-the-button accuracy checks. "The results that we have here plainly show that the accuracy testing was not being done."

Adachi said the problem appears to have started in 2006 or earlier, and that 500 to 1,000 people may have been wrongly convicted of drunken-driving because of the testing issue.

The accuracy checks weren't the only problem with the devices - police discovered last month that the gas used in the testing expired in September 2010, so its true alcohol level was a mystery.

Police have about 20 devices, all of which were pulled from use last month. The device was just one aspect of a field sobriety test - officers also ask suspects to walk a straight line, stand on one leg and touch a finger to the nose, in addition to other sobriety assessments.

Gascón said the department began using the preliminary alcohol screening devices in 2001. Prosecutors and the public defender's office are still in the process of identifying drunken-driving convictions that could be affected by the apparent failure by police to test the devices, he said.

D.A.'s belief

Gascón, who joined Adachi at the press conference, said the evidence so far points to "negligence as opposed to criminal conduct" on the part of police.

He bristled at questions about why the accuracy checks apparently weren't done when he was police chief from 2009 to 2011.

"I don't know how many of you have run large organizations, but even within your own shop, if you know what your secretary is doing every day, I would like to hire you and find out what your secrets are," he said.

"It's impossible, even for myself or for (Chief) Greg Suhr or (former Chief) Heather Fong previously or any of the other chiefs, to have knowledge that there was a failure to follow procedure here," Gascón said.

Deputy Police Chief Jim Dudley, head of the special operations bureau, is leading a department investigation into what went wrong. The devices are used by the traffic division, which is cooperating in the probe, said department spokesman Officer Albie Esparza.

Other tests

Esparza noted that the device is just one part of the normal investigation into a drunken-driving case, and that suspects can opt out of taking the assessment. Suspects must take a separate test at the station with another type of breath-analyzing device or have blood drawn, neither of which has been called into question in the investigation.

The cases in question are the ones where the investigators worked off of the test results to build a conviction. Adachi said anyone questioning a drunken-driving conviction in San Francisco should contact his office at (415) 553-1081 or the attorney who handled the case.