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DWI Blood Test Results Texas – In Austin, Texas you are considered to be legally intoxicated if your blood alcohol content is 0.08% or greater. You cannot drive legally with such a blood alcohol content (BAC) measurement, so law enforcement officers will usually request a test to determine BAC when they suspect impairment due to intoxication. The most common methods for test BAC are breath and blood tests.

Arresting law enforcement officers who believe you have been operating a vehicle while intoxicated can administer a blood or breath test upon your arrest. According to the Texas Transportation Code, Texas implied consent law calls for such a test to be administered according to the arresting officer’s discretion: a police officer can request that you take a portable breath test if they suspect that you have been driving under the influence of alcohol. You are not required to submit to this test and can request to take a blood test. (Note: you can also refuse testing completely; however, if you refuse, there are consequences to consider).

Breath testing is the most common method used for BAC measurement. This is because breath analysis devices, most commonly called breathalyzers, are lightweight and portable, and can provide immediate results (also known as Portable Breath Tests, or PBT). But these tests have a serious margin of error to consider. Poor breathalyzer calibration can result in inaccurate readings, as can software bugs; foreign substances (e.g., asthma inhalers, mouthwash, etc.) and environmental factors (e.g., occupational exposure to solvents and fumes) also can cause imprecise test results. 

There are generally 2 types of breath testing methods; 1) prior to an arrest the officer may ask the driver to submit to a PBT (again, never a requirement), or 2) after arrest, the officer may ask the driver to submit to a breath test at the police station using a stationary unit, often referred to as an intoxilyzer. One interesting fact is that the PBT test is NOT admissible in trial, due to its documented inherent unreliability. However, based on the PBT test results, an officer may still arrest. With the intoxilyzer unit, officers are required to read statutory warnings prior to its administration, following strict guidelines and wait periods (again, no one is ever required to submit to these tests, with the exception of a warrant for drawing blood). If something skews breath test results, they can be invalidated which means they cannot be used as evidence against you. 

Blood testing for BAC is generally a more accurate method to use than breath testing. Analysis of a blood sample yields BAC results but also can detect drugs (including prescription medications) that might be the cause of impairment. The collection method and storage of a blood sample is important because it impacts the integrity of that sample if done incorrectly: waiting too long to take the sample, contamination of the sample, and/or improper storage of the sample (i.e., no refrigeration, etc.) could lead to erroneous results. Any mistakes made during lab testing could lead to inaccuracies, too. If these issues arise, the blood test results can be challenged, and the Court may preclude their use in trial. While an officer may request a sample of your blood, you are not required to submit unless the officer gets a warrant. Note, your refusal to submit to a sample has collateral consequences, including license suspensions, and the prosecution’s suggestion in trial that refusal was because the driver knew they would fail. 

Sometimes an officer won’t even give the arrestee a chance to submit to breath or blood testing and may skip right to requesting a warrant. This often happens if there was a vehicular accident, and/or loss of life related to the arrest. Another way blood is often collected by law enforcement is when an arrestee is taken to the hospital, for whatever reason. Officers will often, lazily, forgo breath and blood test protocols, and simply subpoena your medical records, where the hospital is encouraged to draw your blood for “medical” purposes all while the officer sits with the patient handcuffed to the hospital bed.

Both breath and blood testing have accuracy issues; there are factors that can render either test wholly inaccurate. If you have been arrested and charged with a DWI in the Austin, Texas area, a thorough investigation of the BAC testing procedures by an experienced attorney may allow for the test results to be excluded at trial. The qualified and caring legal team at Jarvis, Garcia, & Erskine Law can help. They understand the distress and worry about being charged with a DWI in Texas. If you find yourself in need of professional legal representation to fight the charges against you in your DWI case, the competent criminal defense attorneys at Jarvis, Garcia, & Erskine Law stand ready to assist you; they will provide valuable legal guidance as to how to proceed in your case. For a free consultation and more information about the legal services available from the knowledgeable and skilled team at Jarvis, Garcia, & Erskine Law, contact them online or call 512-549-6976.