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  • Texas Breath and Blood Testing Q&A

Blood and breath testing are very complicated components of DWI law, and it takes a lot of education to fully understand how they work. Once you know how they work, you know how inaccurate and unreliable they can truly be. Please contact us if your question is not answered below.

How accurate are chemical DWI tests in North Texas?

Urine testing is the least accurate method and is rarely ever performed. The scientific community regards blood testing as the most reliable and accurate method of measuring blood alcohol concentration, but it is inconvenient for police. Breath testing is more convenient for police, but its reliability and accuracy have been debated.

How is breath testing performed in Texas?

The State of Texas uses the Intoxilyzer 5000, more commonly referred to as a breathalyzer. This machine costs about $7,500 and lasts about 10 years before it needs to be replaced. It functions on the theory of infrared spectrosphopy, or the absorption of infrared light. Alcohol absorbs specific wavelengths of light, and the machine is supposed to only detect these wavelengths.

How reliable is a Texas breath test?

The most common argument against breath testing is that the machine might misread other common substances as alcohol. However, nobody other than law enforcement is allowed to test the machine for reliability and accuracy. Additionally, other factors can affect results. For example, a sober person with a fever will have a higher breath test reading than they would without a fever. Bottom line: these machines are fast and cheap, but they have a lot of problems.

Should I agree to a chemical test?

First, ask the officer for permission to call a lawyer. He probably will not let you. Be polite and courteous, and maintain that you need to speak with a lawyer before deciding whether or not to take the test. Eventually, the officer will tell you that if you keep asking to speak with a lawyer, he’ll tell you your actions constitute a refusal. This helps set the stage for a jury trial.

If you fail the test, you’ll be charged. If you pass the test, you could still be charged. If you refuse the test, you’ll be charged. It’s a lose-lose-lose situation. However, if you pass the test, you won’t lose your drivers’ license.

Can I choose a blood test instead of a breath test?

The officer has the choice of which test to offer. You may request a blood test, but they do not have to give you one. However, the Texas State Code states that you may obtain an independent blood test within two hours of your arrest.

Can a Dallas police officer force me to take a chemical test?

You are only obligated to take a chemical test if there has been an accident resulting in death or likely death.

What happens if I refuse a chemical test in TX?

A person arrested for DWI may refuse a requested test. This can result in the following penalties:

  1. a 180-day suspension of your driving privilege on first DWI arrest,
  2. a 2-year suspension of your driving privileges for a subsequent arrest within 10 years if you also refused to submit to a test in your first arrest, and
  3. the prosecutor can admit your refusal into evidence in your DWI trial. The prosecutor will then probably argue that you refused the test because you knew you were intoxicated and that you would fail the test.

If you fail the chemical test, you’ll face:

  1. a 90-day suspension of your driving privilege if your driving record shows no prior alcohol related arrests,
  2. a 1-year suspension of your driving privilege if you have a prior conviction or suspension within the preceding 10 years, and
  3. the prosecutor can admit the results of the test into evidence at your DWI trial.

Call today

We understand that a drunk driving conviction is not an option for you. At The Wilder Firm, we strive for all our clients to be found NOT GUILTY. For a quick response or free evaluation of your DUI/DWI arrest, please contact our Texas drunk driving attorneys at (214) 741-4000.

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