Do I Have to Take a Breath Test Before Being Arrested?

Posted by Phillip Crawford | May 08, 2020

There are two kinds of breath tests in DUI cases: (1) a pre-arrest Preliminary Alcohol Screening (PAS) test, and (2) a post-arrest “chemical test”. For the most part, these two tests look almost exactly the same. In fact, sometimes both tests are given using the exact same machine. So why are there two different tests? The answer is that (unless you are under 21 years old or on probation for DUI), the pre-arrest PAS test is completely optional. As discussed below, there are good reasons to not submit to a pre-arrest PAS test.

            In California, after you are lawfully arrested for driving under the influence of alcohol and/or drugs, you are required to submit to a breath or blood test (aka a “chemical test”). Refusing to submit to a chemical test can result in suspension of your driving privileges for at least one year, even if you are found not guilty of DUI. This is because California has an “implied consent” law (Vehicle Code Section 23612). This statute says that by driving a vehicle in California, you consent to have your breath or blood tested upon being arrested for a DUI. This “chemical test” is not the same as the pre-arrest PAS test; the PAS test is usually completely optional.

            When is the PAS test not optional? There are two main exceptions to this general rule: (1) if you are under 21 years old and lawfully detained on suspicion for DUI; or (2) if you are on probation for DUI (or other certain offenses). Pursuant to Vehicle Code Section 23136(c) drivers under the age of 21 who are lawfully detained on suspicion for DUI are required to submit to the PAS test. Likewise, Vehicle Code Section 23154(c) states that people on probation for DUI are required to submit to the PAS test if lawfully detained on suspicion for DUI. Sometimes, in connection with crimes other than DUI, judges will impose a probation term requiring a person to submit to the PAS test. For all other people, the PAS test is optional.

            So why do so many people submit to the PAS test? There are two main reasons. First, many people (incorrectly) believe that they have to submit to the PAS. Second, people believe that taking the PAS will prove them innocent and that the police will let them go after taking it. However, both of these reasons are flawed.

Most people are not aware of their right to refuse the PAS test. The police usually do not tell people that the PAS test is voluntary. Instead, the police typically pull out the machine and ask the driver to blow into it, “to make sure you are ok to drive.” Most people believe that this is an order from police to blow into the machine, and that they are not free to refuse. This is not true, however.

            Some people know that they do not have to perform the PAS test but choose to anyway because they think that they can prove that they are not driving under the influence. These people think that they will pass the PAS test and will be free to drive away. However, we always tell our clients to refuse the PAS test for several reasons.

            First, PAS breath tests can produce false readings. We will discuss the many issues with the science behind breath tests in future articles. However, it is important to understand that a person's breath alcohol does not necessarily accurately reflect a person's blood alcohol. So, even if your blood alcohol levels are under the “legal limit”, your breath alcohol levels might allow the police to conclude that you are over the limit.

            Second, the PAS machines are not always accurate. Typically, these machines have a margin of error of about .01%, even when they are in proper working order. This .01% can be crucial for people who are right around the legal limit. Think about this: if the machine shows a blood alcohol level of .08%, that means the person's blood alcohol level could be anywhere from .07%-.09%. Of course, the police won't assume that you are at .07% (under the legal limit) and will arrest you for being over the legal limit. Again, this assumes that the machine is properly working. Frequently, the PAS machines are not properly maintained and calibrated.

            Third, even if you “pass” the PAS test, the police may still arrest you. If the police officer gives a person a PAS test, it is because the officer has likely already concluded that the person is under the influence of some substance. If the PAS test comes back somewhere between .01% and .07% the officer can still arrest you for being “under the influence” of alcohol and/or drugs. A person does not have to be above .08% to be considered “under the influence.” In fact, the prosecution's expert will often tell the jury that a person can be “under the influence” at levels as low as .04-.05% BAC. Even if the PAS test comes back at 0.00% BAC, the officer may conclude that you are under the influence of some other drug (including legally prescribed medication) and arrest you anyway.

            Lastly, and most importantly, it is much harder to for the prosecutor to prove a DUI case without the PAS test. Simply put, the main reason police give the PAS test is because it makes it easier to secure a DUI conviction. This is the same with the field sobriety tests (which are also entirely optional). The less evidence the prosecutor has, the harder it is to convict you. 

            The pre-arrest PAS test is completely optional in most circumstances. If you are stopped by the police and suspected of driving under the influence, the best course of action is to politely but firmly decline to do the field sobriety tests, to take the breath test, or to answer ANY questions.  Simply hand the officer your license, registration, and proof of insurance and tell the officer that you won't be answering any questions.  If you are arrested for DUI, only then are you required to take either a blood test or a breath test.  As a general rule, we recommend taking a blood test.

            If you were arrested for DUI and you took a pre-arrest PAS test, you should consult with a DUI attorney to discuss your options and potential defenses. We have successfully defended many cases with bad PAS tests. Call us to schedule a consultation and let us fight for you.

About the Author

Phillip Crawford

Phillip Crawford is an award-winning DUI attorney. In 2018, he won the California DUI Lawyer's Association's top honor when he received the President's Award for excellence in DUI defense. His sole focus is defending DUI cases. Phillip is regarded by judges, prosecutors and fellow defense attorneys as the top DUI in the area who fights passionately for his clients.

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