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DUI Breath Testing in California

DUI breath test results are susceptible to a number of mistakes that may lead to their exclusion from evidence and put the results into question. There are several factors that may cause a breath test to misrepresent a person's blood alcohol concentration ("BAC"). Such factors include, but are not limited to the following:

  1. The officer conducting the test did not adhere to the necessary breath testing protocols [Title 17 of the California Code of Regulations (“CCR”) section 1215 and subsequent sections];
  2. Medical condition (e.g., gastroesophageal reflux disease ("GERD")) or high protein/ low carb diet leading to false result from breath testing device; or
  3. The defendant's BAC was artificially raised by a phenomenon like lingering oral alcohol or growing blood alcohol levels.

Breath test in DUI cases

In DUI cases, law enforcement uses two different types of breathalyzers. These are provided through the following processes:

1. During a DUI traffic stop and investigations. In such cases a preliminary alcohol screening ("PAS") test is administered, and

2. An "evidentiary" breathalyzer test after arrest

a. Preliminary Alcohol Screening (PAS) Tests

During a DUI investigation, a preliminary alcohol screening (PAS) test is administered. This happens after a person has been stopped or pulled over at a DUI checkpoint, but prior to a DUI arrest.

Usually, a PAS is administered using a portable breathalyzer. The majority of drivers are exempt from having to undergo this preliminary examination and are free to decline [Vehicle Code 23612(i) – Right to refuse preliminary alcohol screening DUI breath test.]; but there are certain exceptions. Drivers who are not allowed to refuse to take PAS tests are as follows:

1. Drivers who are currently under probation for a DUI, [ Vehicle Code 13389 (a)]; and

2. Vehicle Code 13388 VC [requiring PAS breath test for DUI suspects under 21]

Refusal to take PAS test

In general, refusal to take PAS test is allowed. PAS test is regarded only as a field sobriety test (FST) [Vehicle Code 23612(h)] and primarily serves to assist the police in determining whether to make an arrest for drunk driving.

The only instances when it results in automatic suspension of driving privileges is when the refusal is by those under twenty-one (21) years of age and those on probation for a DUI. In these two cases, it will be counted as a chemical test refusal. No matter if the driver is found guilty of DUI, their driving privileges will automatically be suspended. [Vehicle Code 13353.1]

If the motorist is 21 years of age or older and not on DUI probation, there is no punishment for refusing to perform a PAS test or any other field sobriety test.

b. Evidentiary DUI breath Test

While taking PAS test is generally allowed without consequences, DUI breath tests in the form of chemical tests are mandatory. The chemical test, which could be blood test or breath test – at the election of the driver, is mandatory such that refusal to take it can lead to serious consequences. Consequences often consist of:

  1. A minimum one-year suspension of one's driving privileges; or
  2. If the motorist is finally found guilty of DUI, they must serve an additional 48 hours in jail. [Vehicle Code 23612(a)(1)(D):]

Under normal circumstances, the driver is given the chance to choose between blood test or breath test. However, there are also instances when such choice is not made available, as in the following:

  1. There exists a suspicion that the driver may be driving under the influence of drugs (“DUID”). In such cases, blood test is required) [Vehicle Code 23612(a)(2)(C).];
  2. The driver is not capable of providing enough sample for DUI breath test;
  3. The driver is unconscious or has died [Vehicle Code 23612(a)(5)]; or
  4. Due to the need for medical care, the driver has been taken to a medical facility where breath testing equipment is not available. [Vehicle Code 23612(a)(3)]

DUI breath test vs. DUI Blood test

DUI attorneys do not generally agree on whether a blood or breath test is preferable.

The key benefit of a breath test is that it is rapid and non-intrusive. Breath test, however, is susceptible to a number of mistakes, as we will show below. These can — and frequently do — produce erroneously high BAC results.

On the other hand, the key benefit of a blood test is that some of the blood that is extracted is kept. A "blood split" motion must then be filed in order to make this blood available to the defendant for independent retesting. Meanwhile, breath samples cannot be preserved in the same way blood samples can be stored. This makes it impossible to conduct subsequent independent testing to confirm the test's correctness.

But in the end, it doesn't matter which test a driver takes; what ultimately matters is whether the police officers adhere to Title 17 guidelines.

Title 17 and DUI breath testing

The DUI chemical testing techniques are outlined in Title 17 of the California Code of Regulations. When collecting and processing DUI breath samples, law enforcement and laboratories must adhere to these protocols.

The accuracy of BAC measurements may be affected if Title 17 protocols are not followed. These mistakes can be used by an adept attorney to counter accusations of drunk driving in California.

A move to exclude evidence pursuant to Penal Code 1538.5 PC is the first stage. The results of the breath test will be deemed inadmissible if the judge allows the application. The defendant's BAC won't be demonstrated. This frequently results in a DUI plea deal or even a complete dismissal of the charges.

a. What are some crucial Title 17 breathalyzer rules?

Title 17 contains a plethora of regulations regarding DUI chemical tests. Among the most significant are the following:

  1. The DUI breathalyzer must be maintained in functional order [ 17 CCR 1220.2(a)(5) and 17 CCR 1221.2(b)];
  2. Every 10 days or 150 usages, whichever comes first, the device needs to be calibrated [17 CCR 1221.2(a)(2)(B)];
  3. The test-giver must get instruction on the particular instrument being used;
  4. Before the DUI breath test is administered, the driver must be watched closely for a continuous period of 15 minutes. During this time, the observing officer must ensure that the driver did not: smoke, eat, drink, or put anything in his mouth, or vomit or burp causing alcohol from the stomach to enter the mouth [17 CCR 1216.1(b)];
  5. Deep "alveolar" air from the lungs must be drawn out for the DUI breath test [ 17 CCR 1215 (r):]; and
  6. Maintenance of equipment calibration results.

b. Erroneous BAC Results

As already emphasized above, police officers effecting the arrest are bound to comply with rules set forth under Title 17. Any deviation from these rules could result in doubts relating to the accuracy of BAC results (which could eventually lead to the dismissal of charges). Common Title 17 violations that may result in BAC results that are artificially elevated include operator error, improper calibration of breath device or failure to maintain documents in accordance with California law

False Readings Due to Medical Condition

A breathalyzer can be deceived into giving a falsely high BAC reading by certain medical conditions and diets. These may consist of gastroesophageal reflux disease, or otherwise known as “GERD,” or low-carbohydrates but high-protein diets, and diabetes.

Even if it doesn't seem relevant, it is imperative for someone who has been charged with drunk driving to inform their DUI defense attorney of ALL the medical conditions and dietary restrictions.

If a medical issue could be used as a DUI defense, a knowledgeable DUI attorney would be aware of it. It might hold the key to preventing an incorrect conviction of a driver based on false DUI breath test results.

Residual Mouth Alcohol Defense

Some alcohol lingers in the mouth's mucosal linings after someone drinks an alcoholic beverage. This is referred to as "residual mouth alcohol." The driver must blow forcefully during a DUI breath test in order to get deep lung air in the sample. However, any remaining oral alcohol is picked up when this breath leaves the mouth.

Alcohol residue in the mouth lingers there for 15 to 20 minutes. Thus, if oral alcohol is present in any quantity, it will be picked up and deposited into the breath sample.

The following situations may result in lingering mouth alcohol:

  • Alcohol that was recently consumed, even if it wasn't enough to render the driver legally intoxicated ("one for the road");
  • cough medicine; or
  • breath fresheners and mouthwashes with alcohol.

After 15 to 20 minutes, the majority of mouth alcohol disappears. This is why Title 17 regulations call for a 15-minute waiting period during which the subject is continuously observed before a DUI breath test can be administered. If the test is administered too soon—or if the subject consumes any alcohol during the waiting period—falsely high BAC readings may result.

Rising Blood Alcohol Defense

After consuming alcohol, blood alcohol levels rise for 30 to 45 minutes afterward. In certain situations, it might take up to two hours for alcohol to enter the system completely. [See National Institute on Alcohol Abuse and Alcoholism, Alcohol Alert No. 35.]

Within this time, a DUI investigation and arrest may take place. This implies that blood alcohol levels at the time a DUI breath test is administered may be greater than they were when the subject was driving.

Speak with a DUI attorney today by calling (626) 827-7222!

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