DWI Tests in Texas
Breath, Blood & Field Tests Can Be Wrong
Just because you were given a test doesn’t mean it was accurate—or legal. From breathalyzers to blood draws, DWI tests in Texas are full of problems. We know how to challenge every result and help you protect your rights in the greater Houston area.
The Truth About DWI Testing
What Police Don’t Want You to Know
Texas law enforcement uses three main types of DWI tests: field sobriety tests, breath tests, and blood tests. But none of them are perfect—and many arrests are based on unreliable results. We dig deep into how your test was handled, whether your rights were violated, and whether the evidence can be thrown out. It’s one of the first places we look to beat a DWI charge.
We know what’s at stake. That’s why we prepare every case for trial, never accept lowball settlements, and go head-to-head with corporations and insurance companies to ensure our clients get the justice and compensation they deserve.
Common DWI Tests Used in Texas
How Police Build Their Case Against You
Officers rely on several types of tests during DWI investigations—but each one has flaws we know how to challenge.
Field Sobriety Tests (FSTs)
These tests include the walk-and-turn, one-leg stand, and horizontal gaze nystagmus. They are highly subjective and often influenced by nerves, medical conditions, poor lighting, or unclear instructions from the officer.
Blood Tests
Blood samples are often taken at a hospital or through a warrant. Although considered more accurate, these tests depend on strict chain-of-custody procedures, and errors in handling or storage can lead to the results being challenged in court.
Breathalyzer (Intoxilyzer 9000)
This device measures your blood alcohol content (BAC) by analyzing your breath. While commonly used, breathalyzers can produce false readings due to improper calibration, operator mistakes, or medical conditions like acid reflux.
Other Tools and Observations
Officers may also use portable breath tests (PBTs), dash or body cam footage, and their own observations of behavior, speech, or appearance. Each of these has potential flaws that we carefully review for inaccuracies or rights violations.
We Know the Labs, the Machines & the Courts
How DWI Testing Works in Houston
In the greater Houston area, breath tests are typically performed using the Intoxilyzer 9000 at designated testing facilities. Blood draws are often sent to local crime labs like the Harris County Institute of Forensic Sciences. We’ve reviewed thousands of lab reports and know where mistakes happen.
Many Harris County officers still rely on outdated field sobriety tactics—especially in areas like Midtown, Montrose, or Westheimer where nightlife arrests are common. We cross-reference body cam footage with arrest reports to spot inconsistencies, poor instructions, or flat-out exaggerations.
Understanding the Evidence Against You
DWI Test FAQ
Do I have to take a breath or blood test in Texas?
Texas has an implied consent law, which means refusing a breath or blood test after arrest can lead to automatic license suspension. However, you do have the right to refuse unless the officer has a warrant. We handle both refusal and consent cases and challenge the legality of the request when possible.
Are field sobriety tests required?
No. You are not legally required to perform field sobriety tests in Texas. These tests are voluntary, and refusing them cannot be used as proof of guilt. In fact, many sober people fail them due to nerves or medical conditions. We regularly challenge the reliability of these tests in court.
Can breath test results be wrong?
Yes. Breathalyzers are prone to errors from improper maintenance, operator mistakes, or even mouth alcohol contamination. We’ve seen cases dismissed due to faulty equipment or procedural problems. Breath test results can be challenged—and we’ve done it successfully across Houston courts.
What if I failed both the breath and blood test?
Even if both tests show a BAC over the legal limit, there are still possible defenses. We look at how the tests were administered, the timing of the sample, the chain of custody, and whether your rights were violated. Failing a test doesn’t automatically mean you’re guilty.
Can I get my test results thrown out in court?
Yes, in some cases. If the test was obtained illegally, conducted improperly, or processed incorrectly, we can file motions to suppress that evidence. We’ve successfully had test results excluded in multiple Harris County courts, which often leads to case reductions or dismissals.
