Houston Office: 713.225.8000 | The Woodlands Office: 281.609.2900

DWI Breath Test

Breath Test DWI under Texas Law

If you have been arrested for driving while intoxicated (DWI), the arresting officer may request that you submit to a breath test on one of the Intoxilyzer 5000 machines used throughout Houston in Harris County and The Woodlands in Montgomery County, TX. Many of our clients are surprised to learn just how little the State of Texas knows about how these machines actually work. Under many circumstances, the Intoxilyzer 5000 is not accurate or reliable.

Although many assume that a breath test over the legal limit of 0.08 will result in a DWI conviction, many of these cases can be fought on any number of technical grounds. Only by seeking out the services of an experienced Houston criminal defense attorney can you learn more about possible defenses that may apply to your case.

Houston Lawyer for DWI Breath Tests

Call Matt Horak to discuss effective ways to fight the criminal DWI charge made against you involving a breath test reading over the legal limit of 0.08. Matt Horak represents clients charged with DWI in Houston for Harris County and in the Woodlands for Montgomery County, Texas.

Back to top

Whether the Consent to Give the Breath Sample was Voluntary

In certain cases, the facts of the DWI case raises an issue as to the voluntariness of the defendant’s consent to give a specimen, the issue should be submitted to the jury. The defense must request this instruction in appropriate cases. See Turpin v. State, 606 S.W.2d 907, 914 (Tex.Crim.App. 1980); Hall v. State, 649 S.W.2d 627 (Tex.Crim.App. 1983).

For cases in which the prosecutor for the State of Texas introduces into evidence a breath test result, the jury may be read a jury instruction which generally states:  

You are instructed that before you can consider the breath test result as evidence, the burden of proof is on the State of Texas to prove by clear and convincing evidence that the breath specimen obtained from the defendant, if it was, was voluntarily and freely given by the defendant with his consent, and that there was no promises of benefit to induce him to consent to the taking of a breath specimen or physical violence, duress, or threats used against the defendant.

Therefore, if you do not believe by clear and convincing evidence that the defendant did voluntarily and freely consent to giving a breath specimen for the purpose of determining the alcoholic content, if any, you will not consider any portion of evidence introduced before you concerning the purported alcoholic content of the defendant’s breath specimen. 

Back to top

Compliance With Rules for Taking Breath Specimens under Texas Law

The Courts have ruled under Atkinson v. State, 923 S.W.2d 21 (Tex.Crim.App. 1996), that if the defendant raises an issue of fact concerning compliance with the DPS rules for taking a breath specimen then the court should instruct the jury on the matter. The defense must make a request for the instruction pursuant to the exclusionary rule in CCP 38.23. See Atkinson, 923 S.W.2d at 23-24; 37 TEX. ADMIN. CODE §19.4(c).

The State of Texas has introduced test results from a breath specimen taken from the defendant. 

You are instructed that before you may consider the results of any test of a specimen of the defendant’s breath, you must find beyond a reasonable doubt that the regulations of the Texas Department of Public Safety were complied with in administering the test.

The regulations of the Texas Department of Public Safety include:

  1. the breath alcohol testing instrument and reference sample device must be operated by either a technical supervisor or certified operator and only certified personnel have access to the Intoxilyzer 5000;
  2. a period during which an operator is required to remain in the presence of the subject. An operator shall remain in the presence of the subject at least 15 minutes before the test and should exercise reasonable care to ensure that the subject does not place any substances in the mouth. Direct observation is not necessary to ensure the validity or accuracy of the test result;
  3. the analysis of a reference sample, the results of which must agree with the reference sample predicted value within plus or minus 0.01g/210 L, or such limits as set by the scientific director. This reference analysis shall be performed in conjunction with subject analyses;
  4. the use of a system blank analysis in conjunction with the testing of each subject;
maintenance of any specified records designated by the scientific director;
  6. all analytical results shall be expressed in grams of alcohol per 210 liters of breath (g/210L);
  7. designation that the instrumentation will be used only for testing subjects that are suspected of violating any statute or rule that defines intoxication in terms of alcohol concentration; and in compliance with the requirements of the Department (relating to Operator Certification); and
  8. supervision of certified operators and testing techniques by a technical supervisor meeting the qualifications required by the Department (relating to Technical Supervisor).

If you have found beyond a reasonable doubt that all of these requirements were complied with, then you may consider the results of the test in your deliberations.  But if you do not find, or if you have a reasonable doubt as to the compliance, then you may not consider the breath test or its results for any purpose and shall not consider it whatsoever in arriving at your verdict.

Back to top

Texas DUI Breath Test Resources

Texas Breath Test Operator Manual (PDF) – Read more about how the Intoxilyzer 5000 works by reading the breath test operator’s manual.

DWI consequences for a First DWI – Read more about the penalties for a first DWI in Texas and how these cases are prosecuted in Houston for Harris County and The Woodlands for Montgomery County. Find out about common defenses, read the jury instructions, and more. 

DWI consequences for a Second DWI – After a second DWI arrest the penalties and punishments are enhanced under Texas law. Find out more about the penalties for a second or subsequent DWI arrest and prosecution in Houston or The Woodlands, TX.

Back to top

Fighting the DWI Breathalyzer Case

If you have been arrested for DWI and allegedly blew over the legal limit of 0.08 or refused to take the breath test then contact an experienced Houston DWI attorney. Matt Horak focuses on breath test cases and effective ways to fight these criminal DWI charges.

Horak Law defends clients all over Harris County and surrounding areas. Call (713) 225-8000 for a consultation today.  

Back to top


Use the form below to request a confidential case review with an attorney.

"*" indicates required fields

Our Locations


5300 Memorial Dr 750 A
Houston, TX 77007


25911 Oak Ridge Dr
The Woodlands, TX 77380