In our last post, we began looking at a recent story on faulty breathalyzer devices used as part of field sobriety tests in San Jose County, California. Those devices reportedly had a manufacturer's error that caused condensation to accumulate inside the breathalyzer tube, which may have distorted readings and caused errors in DUI pre-screening.

Defense attorneys said cases where DUI suspects blew into the devices but refused blood tests are particularly suspect, as prosecution may lose its primary evidence in those cases. Defense attorneys will be looking to get cases involving the devices back into court and litigate based on the new information. Sources said some DUI suspects who were subjected to the device may have already received their conviction and served their sentence.

Defense attorneys often request that evidence gathered by field breathalyzers be dismissed. Defense attorneys reviewing the DUI cases in question say it is too early to know what kind of effect the breathalyzer defect will have in cases where prosecutors have alternate evidence like blood tests. One public defender said that, in cases where there is no evidence of DUI beyond the field breathalyzer test, the district attorney would likely dismiss the case.

The breathalyzer device is often used to establish probable cause, but of itself it is simply one factor when an officer considers whether to arrest an individual. But even if the breathalyzer tests yielded faulty results, police insist that the arrest were still valid, as they use a number of factors to determine whether to arrest a DUI suspect. Sources said officer sometimes don't even use the breathalyzers before making DUI arrests.

The Santa Clara County District Attorney's Office said it would take at least a month to review the cases and determine how many will be dismissed.

Source: mercurynews.com, "Santa Clara County DA reviewing 865 San Jose DUI cases after breathalyzers deemed faulty," Mike Rosenberg, 4 May 2011.