Top 2 PAS Test Defenses

Highly Sucessful Preliminary Alcohol Screening Defenses

Top 2 PAS Test Defenses

For motorists under 21 and folks on DUI probation, the law makes it illegal to drive with a blood alcohol concentration of .01% or greater. It also allows law enforcement to use the less-reliable preliminary alcohol screening (PAS) test instead of an evidential chemical breath or blood test.

There are two defenses that are particular to the PAS device used in these cases: one procedural and one substantive. The procedural defense involves the foundation required to be laid for the PAS results to be used in evidence. The substantive defense is based on the margin of error of the PAS device.

These PAS defenses are among the most successful in our office.

PAS Test Defense #1


Because the preliminary alcohol screening (PAS) test is not subject to the rigorous regulation scheme in Title 17, it does not carry the presumption of reliability that goes with evidential chemical testing. Accordingly, DMV must actually prove the test is reliable before relying on it to suspend your license. Courts call this showing of reliability the foundation for admitting the PAS test into evidence.

Breath test foundations are governed by the three-part standard announced in the case of People v. Adams (1976) 59 Cal.App.3d 559, and are known by shorthand as an “Adams foundation.” DMV can establish an Adams foundation for a PAS test by showing (1) that the officer was competent and qualified to administer the PAS test; (2) that the PAS device was in proper working order at the time of the test; and (3) that the officer administered the test properly. Only by establishing all three of these foundational elements will DMV be able to rely on the PAS test to suspend a license.

This defense is by far the most common for hearings involving a PAS test because, properly done, the foundation requires DMV to call as witnesses both the arresting officer and the PAS calibration officer. Rarely will DMV call both of them to the stand, and that results in an inadequate foundation under People v. Adams.

PAS Test Defense #2


This is the holding of the unpublished case of Nazerian v. DMV (2d Dist. 2005) 2005 WL 1576246. If an expert testifies to the margin of error of the PAS device (usually at least plus or minus 0.01%), then a reading of 0.01% could be as low as zero, which of course would not violate the law. DMV has the burden of proving that your BAC was 0.01% or greater–not that it might have been 0.01% or greater. Thus, with the proper expert testimony, the PAS reading will have to be at least 0.02% to result in a suspension.

You will want to review the maintenance and calibration records for the PAS device used in your case, as they may well show the machine reading above the known standard. If so, have an expert testify at the hearing that the margin of error renders a reading of 0.01% statistically meaningless and demand a set aside of the suspension.

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