The Law Office Of H. Alex Fuller, PLLC

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The Law Office Of H. Alex Fuller, PLLC

Call His McKinney Office To Request A
Free, Confidential Consultation

The rules of DWI chemical tests in Texas

Driving while intoxicated in Texas can result in a misdemeanor DWI charge.

The most common form of evidence in a DWI case is proof of blood alcohol concentration shown through chemical testing. However, there are flaws in the process.

How does a chemical test work?

The most common form of chemical testing uses breath to determine BAC. However, police officers may use blood or urine if they suspect the driver is under the influence of drugs. The BAC limit in Texas is 0.08%, and officers need roughly 210 liters of breath, 67 milliliters of urine, or 100 milliliters of blood for the most accurate testing.

What are the problems?

There are many ways that chemical testing can result in incorrect BAC levels, especially with breath testing. Some common issues include:

  • Contamination from some foods or medications
  • Operator or machine error
  • Calibrating improperly
  • Confusing samples
  • Manipulating the test
  • Using an unclean device

A breath test may detect the presence of alcohol from chewing gum, mints, mouthwash, and cough drops.

Can you refuse?

According to Texas transportation law, drivers give their consent to chemical testing by simply operating a vehicle. A driver can refuse chemical testing if pulled over for a DWI or DUI. However, there will be consequences. The officers will likely place the driver under arrest, and the driver should expect a minimum of license suspension. The period of suspension depends on the number of refusals.

Keep in mind that a DWI charge is not the same as a DWI conviction. Drivers will face a judge and have the chance to contest the charge.


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