In California, after a driver is stopped for suspected DUI, he or she may be asked to take a Preliminary Alcohol Screening (PAS) test by the law enforcement officer.  The PAS is done by blowing into a hand held breach machine.

Taking a PAS test is optional.  An officer is suppose to tell the driver that he or she is not required to take a PAS.  California Vehicle Code section 23612(h) requires an officer to advise a person that they have a right to refuse the PAS. 

The problem is that many DUI defense attorneys ignore this requirement, and the PAS is given more weight in both the DMV hearing and possibly in a motion to suppress.  Hiring a qualified California DUI attorney will help in determining whether a driver was advised of the right to refuse a PAS test, or simply told to blow into the machine, thinking they have no alternative.