How to Challenge a Breathalyzer Result in a Texas DWI Case

A breath-test result showing an alcohol concentration above the legal limit can be intimidating. Many drivers believe the number alone guarantees a conviction. However, breath-testing evidence depends on proper equipment maintenance, qualified operators, and legally acceptable testing procedures. Errors involving any of these areas may affect the reliability or admissibility of the result. At The Law Office of Alex Tyra, P.C., we examine the circumstances surrounding breath testing in DWI cases throughout Longview and East Texas.

The Role of Breath Testing in Texas DWI Prosecutions

Texas Penal Code § 49.01 defines intoxication to include an alcohol concentration of 0.08 or more. Under § 49.04, a qualifying test result of 0.15 or higher can also support a Class A misdemeanor enhancement.

These legal consequences make the accuracy of the reported result especially important.

A breath-testing instrument does not directly measure the alcohol concentration in the driver’s blood. Instead, it analyzes a breath specimen using an approved testing method to estimate alcohol concentration.

Examining Equipment and Testing Procedures

We review whether the testing equipment was approved, properly maintained, and operated by an authorized individual. Maintenance documentation, quality-control records, and information about the testing sequence may reveal issues requiring further investigation.

We also examine whether the officer complied with applicable procedures before and during the test. Certain circumstances involving residual mouth alcohol, equipment problems, or other testing irregularities can affect reliability.

Not every procedural deviation automatically invalidates a result. The legal significance depends on the specific error, the governing requirements, and the evidence presented.

The Timing of the Test Matters

A breath sample is often collected some time after the person allegedly operated the vehicle. Alcohol absorption and elimination can cause the concentration measured later to differ from the concentration present during driving.

We consider the timing of alcohol consumption, the stop, the arrest, and the test. Where supported by the evidence, these issues may be relevant to the prosecution’s theory of intoxication.

Call The Law Office of Alex Tyra, P.C. for Your Free Consultation

A breath-test result should be examined, not simply accepted without question. If you face DWI charges in Longview or East Texas, call The Law Office of Alex Tyra, P.C. at (903) 753-7499 for your free consultation.