PAS (Preliminary Alcohol Screening) Tests in California DUI Cases

pas test dui los angeles

Please click on the links below to go directly to your topic of interest:

What is the PAS test

Many DUI arrests involve PAS testsPAS test is a “preliminary alcohol screening” test, accomplished through the usage of a portable DUI breathalyzer, dubbed a PAS device.  Portable breathalyzers, or PAS devices, are carried by many police officers on patrol and are used as a tool in a DUI investigation.  A DUI investigation usually begins after a traffic stop or a traffic collision.  When police observe a traffic violation and conduct a traffic stop, or when a police stop is dispatched to a traffic collision, they will look for any objective signs of intoxication from the drivers involved.  If a police officer smells alcohol or observes a tired demeanor, an unsteady gait, extreme sleepiness, or unusual reactions, he might suspect that you are drunk driving.  If they believe that, you are likely to be requested to submit to sobriety tests.  These series of tests are done in the field and are therefore referenced as the field sobriety tests.

The field sobriety tests, or FSTs, can be several of various tests, usually ending up with a preliminary alcohol breathalyzer test, abbreviated as the PAS test, used to determine the presence of alcohol in your blood.

All Field Sobriety Tests are voluntary and you do not have to agree to do them.

The observation of a DUI police officer is very subjective and will result in an arrest unless you can show the alcohol level in a PAS device that is below .08% BAC.  For example, if you blow .07% BAC and you are not on DUI probation or a teenager drunk driving, many police officers will overlook imperfect performance on the other FTSs, such as a walk-and-turn test, a one-legged-stand test, and a finger-to-nose tests.

A PAS device is a DUI investigation tool that is supposed to be used only to determine the presence of alcohol.  Consequently, many police agencies ask DUI suspects to give only one breath sample into a PAS breathalyzer machine.  For example, it is not uncommon to have Riverside County DUI investigation officers get only one sample of breath and arrest a DUI driver based on that one sample.  However, one sample cannot be used to tell the BAC level because California Law requires a BAC breath sample of two samples that fall within .02 of each other.  For Example, two samples of .07% BAC level and .09% BAC are reliable but two samples of a .07% BAC and .010% BAC are not.  This rule comes from the California Code of Regulations Title 17, section 1220.4.  If a single PAS test result is reported, there is no confirmation of that result by the second test and the first test result cannot be relied on to show a specific alcohol level.  Thus one sample can be used to show the presence of alcohol.

Here is another reason why a PAS device can be used to measure the alcohol presence but cannot be used to measure the level of alcohol.  To register a breath sample on a breathalyzer, 1.5 liters of breath needs to flow into the PAS device.  When a suspected drunk driving driver does not blow hard enough to give 1.5 liters of air, the PAS machine tires to bypass the legal requirements of Title 17 and “trap” a sample of breath by a “manual trap” function.  A manual trap will not account for the mouth alcohol and can incorrectly show an alcohol level that is not reflective of the true alcohol level.  A DUI PAS test is not equipped with a way to eliminate mouth alcohol.  This is commonly done with a slope detector.  If you are being prosecuted based on a PAS DUI test alone, contact a Los Angeles DUI attorney to explain how you can win your Los Angles DUI.

Preliminary Alcohol Screening Test (PAS) Refusal

During a Los Angeles DUI investigation, a police officer might ask you to submit to a preliminary alcohol screening test (PAS test).  The preliminary alcohol screening test is not mandated by law.

Will Preliminary Alcohol Screening Test Refusal affect my license?

A refusal to submit to a PAS test should have not any consequences on a driver’s license unless you are a minor or a person who is already on probation for drunk driving.  DUI attorney Los Angeles recommends that you do not submit to a PAS test unless you have consumed alcohol shortly before being pulled over – because it will help establish a rising blood alcohol level defense.  If you consumed alcohol shortly before being pulled over, the PAS test should show a lower alcohol level.  The subsequent post-arrest chemical alcohol test then will show a higher blood alcohol level and will establish a rising blood alcohol defense.  A rising blood alcohol defense is one of the most successful defenses used by Los Angeles DUI attorneys in fighting DUI cases in court and the DMV.

Vehicle Code Section 13353.1 shows that minors and persons who are on probation for a DUI cannot refuse to submit to a breath alcohol test.  Unlike an adult,  a refusal to submit to a preliminary alcohol screening test will have terrible severe consequences for drivers who are under 21 years of age. The severe consequences are related to the driver’s license only and are decided at the DMV and not in court.  In contrast, a refusal to submit to a chemical test can have severe consequences in court;  here, we are only focused on the DMV administrative consequences for drivers – a decision made at the Driver’s Safety office of the DMV.

“Minor Drivers” are not allowed to consume alcohol at all while driving. For purposes of drinking and driving, “minor” is considered anyone who is under the age of 21.  A minor who refuses to submit to a preliminary alcohol screening or PAS test can have his or her license suspended for one year if there are no prior DUI-related offenses or revoked for 2 years if he or she has one prior DUI-related offense within the past ten years.  A minor who refuses to submit to a PAS test and he has two prior DUI-related offenses will have his license revoked for 3 years (CVC 13388).  If you are a minor who is charged with a DUI-related offense call Los Angeles DUI attorney right now to talk to an attorney directly.  A refusal to submit to a chemical test will carry harsher consequences for a driver under 21 years of age because a refusal fiding prevents getting a “critical need” restricted driver’s license.

The consequences for a person on DUI probation are almost identical to an “under 21 driver” and a refusal to submit to a chemical test can result in a driver’s license suspension for at least one year.  If you are on DUI probation and you do have a prior DUI-related offense, you can lose your driver’s license for two years.  Two or more prior DUI-related offenses for a person who is on DUI probation can result in a loss of license for three years.

A prior for an administrative finding by the DMV is any of the following:

  • 01% Minor infraction DUI (CVC 23136); wet reckless;
  • .05% Minor DUI (CVC 23140);
  • DUI (CVC 23152);
  • DUI with injuries (CVC 23153);
  • Vehicular Manslaughter (California Penal Code 191.5 and 192.5(a));
  • Previous DMV finding of refusal to submit to a test (CVC13353);
  • Previous DMV findings of driving with a BAC equal to or higher than .08% (CVC 13353.2).

Can PAS Test Refusal Be Used Against Me In Los Angeles DUI Case?

Sometimes during a DUI investigation, the investigating officer will request the driver suspected of a DUI to submit to a chemical PAS Test to determine if probable cause exists for arresting that driver. That chemical test is known as the PAS test, an abbreviation for a preliminary alcohol screening test. The devices that are used by officers for the PAS test are handheld instruments such as Alco-Sensors manufactured by Intoximeters Inc. If the driver blows above .08% blood alcohol concentration during the PAS test, the investigating officer will most likely place the driver under arrest.  In many Los Angeles DUI investigations, the police arrest drivers even if when the blood alcohol concentration is below .08% BAC. If you are one of such unlucky drivers, please contact Los Angeles DUI attorney to help get your Los Angeles DUI dismissed.  After the arrest, the driver is usually taken to a police station or a medical facility where more reliable chemical testing is conducted to confirm the results of a PAS test or to draw blood. If the driver refuses to submit to a chemical test, he can be charged with a special allegation for refusing to submit to a chemical test. Such special allegations carry additional mandatory two days of jail time and a 9-month-long DUI program.


As a Los Angeles DUI Lawyer, I often defend “refusal DUIs”; and will address the strategy, methods, and defenses of “refusal DUI” in later articles. Here, I am focused only on the limited issue of refusal to submit to PAS. While there is no legal requirement to submit to a PAS test, the overzealous prosecutor might try to show the trier of facts that failure to submit to a PAS test shows consciousness of guilt. This is based on a jury instruction that seems to allow Los Angeles DUI prosecutors to argue, “why else did the driver refuse to submit to a PAS test if not because he had too much to drink”. That issue was addressed by a California Court of Appeals in 2010 in the case of People v. Jackson (189 Cal.App.4th 1461). In Jackson, once he was informed of the right to refuse to submit to a PAS test he did so. At trial, the prosecutor introduced refusal to submit to PAS as a consciousness of guilt, and the defendant was convicted of a DUI. The court opined that because there is a statutory right to refuse to take the PAS test, the introduction at trial of the refusal as a consciousness of guilt was an error. In Jackson, it was deemed a harmless error due to overwhelming evidence against the defendant, but it established a law that all courts are now required to follow and it should not be admissible in any trial. Additionally, it can not be used by the prosecutors as an argument during plea negotiation, which Los Angeles DWI lawyers will use for your benefit.

PAS (Preliminary Alcohol Screening) Test in LA DUI Cases

Usually, a Preliminary Alcohol Screening Test is not used to prove an alcohol level.  In many DUI cases, a DUI driver submits to a breath test or blood test in the station or hospital at the conclusion of a Los Angeles DUI investigation.  This chemical test is called, an evidentiary test, because it is used as evidence of blood alcohol level.  Because the PAS test is a field sobriety test,  a DUI suspect is asked to submit to a preliminary alcohol screening test, which is called, a PAS test.

A preliminary alcohol screening test is accomplished using a portable device, such as Alco-Sensor IV or similar devices.

As discussed above, a preliminary alcohol screening device needs to capture at least 1.5 L of air to give a reading.  When a preliminary alcohol screening (PAS) device results are below .08% BAC or the results are consistent with a rising blood alcohol defense, Los Angeles drunk driving attorney will subpoena the officer administering the test and officer maintaining the device to introduce the results of the preliminary alcohol screening test into evidence.  The law that explains how to introduce a preliminary alcohol screening test comes from the Court of Appeals case People v. Adams, a 1976 case that explains how to “lay the foundation” for the introduction of a Preliminary Alcohol Screening test.  “Foundation” is just a legal word for “requirement”.

The foundation for the introduction of the preliminary alcohol screening test consists of 3 things:

  1. Something to show that the machine used was in proper working order.  This is accomplished by requesting that a PAS coordinator, an officer with the agency that keeps the PAS devices, testify that he maintained the PAS device according to the state law and manufacturing specifications.
  2. Something to show that the test was properly administered.  This is accomplished by having the arresting officer testify that he complied with the law governing the administration of the test, such as Title 17 of the California Code of Regulations.
  3. Something to show that the operator (aka, the DUI officer) was competent and qualified.  This is shown by having a police officer testify about his training.

When all three factors are present, Los Angeles DUI Attorney can introduce the PAS device and use it to prove the blood alcohol level at the time of preliminary alcohol screening.  Without that, the preliminary alcohol screening can not be used for actual value but can use only to show the presence of alcohol in the blood.

If preliminary alcohol screening test results are below .08% alcohol in blood, its introduction will help the defense in showing that the driver was below .08%.

Conversely, the prosecution might want to introduce PAS results because they are above .08%, but, your Los Angeles DUI Lawyer may be able to limit the introduction of the preliminary alcohol screening because of noncompliance with the Adams case.

Los Angeles DUI attorney can help you win your case.  Los Angeles DUI lawyer will also represent you at a DMV hearing.  If you call our office at (818) 921 7744, to talk to one of the best Los Angeles DUI attorneys during a free consulation.
call DUI Attorney

(818) 921 7744  CALL anytime to talk directly to Los Angeles DUI Lawyer.

waste of timepoornot badgoodexcellent (5 rating, 1 votes)