When a person is arrested for criminal DUI in Torrance he or she surrenders the drivers license to the officer but may request a DMV hearing to get it back. The primary issue at the hearing is usually whether the BAC was .08 or more at the time of driving. To establish that element the DMV will introduce a breath result and hang there hat on that evidence. So what does the attorney do to challenge that?

Well, he cannot simply raise doubts about the reliability of the sample because the DMV gets what is called an “official duty presumption” when it relates to the breath test results.
DMV may satisfy its burden of proof with the presumption set forth in Evidence Code section 664 that official duty has been regularly performed. Police officers have an official duty to perform blood-alcohol analyses by methods devised to assure reliability and to accurately report the facts of an arrest for drunk driving. Sections 1215 et seq. of title 17 of the California Code of Regulations contain the standards for breath alcohol analysis, including the collection and testing of samples, for instrument performance, and for approved instruments. Compliance with those standards gives rise to an inference that the blood alcohol test results are trustworthy, establishing a foundation for the admission of test results and a basis for finding that such results are legally sufficient to support requisite findings in an administrative per se proceeding. The DMV is not required to present additional foundational evidence at that point. Rather, the driver must produce affirmative evidence of the nonexistence of the presumed facts sufficient to shift the burden of proof back to DMV.
So what must the attorney do to overcome this presumption? “The licensee must show, ‘through cross-examination of the officer or by the introduction of affirmative evidence, that official standards were in any respect not observed” Once such showing has been made, the burden shifts to the DMV to prove that the test was reliable despite the violation.” ’ ” (Brenner, supra, 189 Cal.App.4th at p. 370; Manriquez, supra, 105 Cal.App.4th at p. 1233.) This task is easier said than done in most cases.