DUI Blood & Breath Tests

Southern California DUI Attorney Providing the Answers You Need

When officers are able to determine probable cause, or in other words, are able to confirm their reasonable suspicions that someone has been driving while under the influence, the officer will place the suspect under arrest. Upon arrest, the officer has the authority to conduct a warrantless search of the individual by requesting he/ she submit to a chemical test. This search is legally permissible, which means the results can be submitted to the court as evidence, provided the search is done properly via an approved method resulting in a blood or breath test.

At Parker Law Center, Attorney Kellee Parker Harris understands how critical this process is, and that even the smallest mistakes can result in unreliable evidence which could cause a wrongful conviction should the errors go undiscovered. As an experienced Southern California DUI attorney, she knows what it takes to challenge these chemical test results. Thoroughly evaluating and reviewing all of the evidence related to the case could result in a potentially case-changing error that can make the difference between a conviction and having the case dismissed.

DUI Blood Tests

If arrested for driving under the influence of alcohol you have the choice to submit to a breath or a blood test. If you select the breath test then you will be informed of Trombettawhich advises you that a breath sample cannot be maintained for later testing; thus, following your breath test you still have the option to submit to a blood test. Any time you submit to a blood test your blood sample will be maintained by the crime lab. Additionally, it will be made available for retesting at a later date should you chose. If you are arrested for driving under the influence of drugs then you will be required to submit to a blood or urine sample. DUI blood tests must adhere to extremely stringent procedures under Title 17, including requirements for the draw, preparation of the vials, handling the sample, analysis, construction of reports, and more. Even simple mistakes in these procedures could lead to unreliable evidence which could result in the blood alcohol content being suppressed from your trial and/ or DMV hearing.

DUI Breath Tests

If an officer arrested you for driving under the influence of alcohol then you have the right to select a breath test as your chemical test. If the officer suspects you were driving under the influence of drugs then you do not have the option to submit to a breath test as breath tests can only determine alcohol content. A chemical breath test can either be performed in the field via a handheld device or back at the police station on a large stationary device. The breath testing device analyzes the amount of alcohol in your breath and that number is converted via partition ratio to reflect the blood alcohol content. The blood to breath ratio utilized is 2100:1; however, it can vary due to a number of factors such as blood plasma, temperature, etc. A change in the blood breath ration could result in the breath test overestimating the true blood alcohol content. Breath tests must have accuracy checks performed at minimum every 10 days according to Title 17 to ensure the machine is measuring standards accurately. The margin of error on the breath testing device is 0.01%. Thus, if a known value of 0.100% is introduced an output as low as 0.09% and as high as 0.110% would be within specifications. Officers must administer tests exactly according to Title 17 requirements to ensure proper administration and to avoid potential contamination and/ or mouth alcohol which could lead to inaccurate results.

Can You Refuse To Take This Test?

California’s “implied consent” law mandates that all drivers give their consent to take a blood or breath test post arrest when requested by a peace officer. Thus, by law you are required to submit to this test without first speaking to an attorney. Should you refuse to submit to a breath or a blood test then you will be subject to enhanced penalties in court including mandatory jail time and a longer license suspension. Furthermore, just because you refuse to provide officers evidence of your blood alcohol content it does not mean that you cannot be prosecuted in court. Vehicle Code Section 23152 (a) provides that it is unlawful to drive under the influence of alcohol. This code section does not require a blood alcohol level in order to be found in violation. In order to prove “under the influence” officers are looking for signs of impairment: slurred speech, unsteady gait, odor of alcohol, bloodshot/ watery eyes, poor driving, poor performance on standardized field sobriety tests, etc. While a conviction in court will result in enhanced penalties, the APS action designating you as a refusal will prohibit you from obtaining a restricted license. If you refused to submit to a chemical test you need to speak with a skilled DUI attorney today to determine if you can challenge the refusal designation under the defense that you were not properly admonished.

Get help from a Southern California DUI attorney if you have been arrested and charged with driving under the influence! Contact Parker Law Center today by calling (800) 805-8804 to request a free consultation.

Why Hire Parker Law Center?


A DUI is a criminal offense that can result in serious penalties. Turning to a seasoned and skilled defense lawyer that focuses on handling DUI cases can make a major difference.


Hiring an attorney does not have to break the bank. Parker Law Center aims to provide all of our clients with effective DUI representation at an affordable and reasonable rate.


Our aggressive defense strategies have enabled us to successfully represent a variety of complex misdemeanor and felony DUI cases across Southern California.

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Our firm brings over a decade of insight and experience in the area of DUI law. We have also found success with the number of cases we have taken to trial. When you place matters into our hands, you can depend on us to fiercely advocate for your rights and protect your driving privileges.