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Challenging a Breathalyzer

Dec 05, 2018 by Mike McKneely in Criminal Defense, DUI
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On a weekend, say you were out with some friends and indulged in a drink or two. Knowing that you had to drive, you were careful not to drink too much. However, while navigating your way home, you get pulled over for what seems to be a routine traffic stop. The next thing you know, the officer is giving you a breathalyzer test, but you are confident that you are perfectly able to drive. Shockingly, the results came back saying that your BAC is over the legal limit, and now you’re facing driving under the influence (DUI) charges.

If you have found yourself in this situation, the most important thing is to realize that breathalyzer tests are not infallible, and the results can be successfully challenged in court. Fresno DUI attorney Michael McKneely help you with your drunk driving case. To schedule a free and confidential case consultation, contact Michael McKneely, Criminal Defense Lawyer today at (559) 443-7442.

California Law Strictly Regulates the Use of Breathalyzer Tests

In California, driving with a BAC of .08 percent or higher means that you can face DUI charges. Law enforcement, therefore, relies heavily on the results obtained from breathalyzer tests administered during traffic stops. Most people are not aware that California law imposes strict requirements regarding administration of these tests.

Legal Requirements Regarding Equipment and Training

California law has specific requirements regarding who can administer the test and the equipment itself. Some of these regulations include:

  • The testing device must be kept in good working order.
  • In order to ensure accurate results, the testing device must be properly calibrated and re-calibrated.
  • The officer administering the test must receive proper training.

Law enforcement agencies are required to keep detailed and specific records regarding training of personnel, upkeep and calibration of testing devices, and test results. You may be able to successfully avoid conviction if you the prosecution cannot prove that the officer did not receive proper training, or the breathalyzer had not been properly calibrated.

Legal Requirements Regarding Administering Breathalyzer Tests

California law also has specific requirements regarding how breathalyzer tests are administered. Such rules include:

  • The test can be administered only after the officer has continuously observed you for at least 15 minutes prior to giving the test.
  • During the time that the officer is observing you, you cannot do any of the following: eat, drink, or put anything else into your mouth; burp, vomit, or regurgitate into your mouth; or smoke.
  • The breathalyzer sample must be air from deep in the lungs (the officer should have instructed you to take a deep breath).

Breathalyzer tests can be successfully challenged if the officer administering the test failed to meet any of the requirements above. If your Fresno DUI lawyer can prove that your breathalyzer test failed to meet one or more of these requirements, the test results are deemed to be unreliable and are therefore excluded from the evidence presented to the court.

Defenses in Your DUI Case

Even if there are no issues with how the test was administered, you may still have a basis for challenging the results of the breathalyzer test. Many diet and health conditions can lead to false or inaccurate BAC results in breathalyzer tests, including:

  • Diabetes
  • High protein/low carb diets
  • Chronic heartburn, acid reflux, and other digestive conditions

In addition to the issues that can be caused by health or diet, breathalyzer tests are also unreliable when there was any residual alcohol present in the mouth when the test was given. This could include a single alcoholic drink right before driving (even if it was your only drink), but also mouthwashes, breath sprays, or cold medicine.

Contact a Fresno DUI Lawyer for Help Today

DUI convictions carry very serious consequences such as fines and jail time, and can even limit your ability to work or find employment. If you’ve been charged with DUI and you believe the breathalyzer test was inaccurate, contact Michael McKneely, Criminal Defense Lawyer. With years of experience defending clients in the Fresno area, he has the skills you need to get you a fair result. To schedule a free consultation, contact us today at (559) 443-7442.



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