Breath and Blood Evidence
Breath Test Defense in Texas
A breath test result looks like a fact. It is a measurement produced by an instrument, operated by a person, under conditions that are written down and can be checked.
The machine does not measure your blood. It measures your breath and converts one to the other using a fixed ratio, and that conversion is where a great deal of the argument lives.
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What the Intoxilyzer 9000 actually measures
Texas breath testing runs on the Intoxilyzer 9000. It samples deep lung air and reports a figure, but the figure it reports is not a blood alcohol reading. It is a breath measurement converted using an assumed ratio between breath and blood.
That ratio is an average drawn from population data. It is not measured from you on the night, and individuals vary from it. Where a result sits close to a threshold, the difference between an assumed average and an actual person is not a technicality.
Texas law is written to accommodate this. Penal Code section 49.01(1) defines alcohol concentration by reference to grams of alcohol per 210 liters of breath, per 100 milliliters of blood, or per 67 milliliters of urine. Three different specimen types, three different denominators, one statutory term.
The paperwork behind a breath result
A number on a printout is the end of a process that generates records at every stage, and those records are obtainable.
A reliability review of an Intoxilyzer 9000 result begins with the complete test sequence, not only the final number. Operator certification, the instrument's status and maintenance information, quality-control data, and documentation of the required observation period can show whether the test was conducted under the Breath Alcohol Testing Program's operating requirements. Section 724.018 provides a right to full information about the analysis on request.
The timestamps should then be compared with body-camera and booking video. That comparison can show what happened during the observation period, whether anything entered the person's mouth, whether regurgitation or another interruption was documented, and whether the operator's written record matches what occurred. The point is to evaluate the instrument, operator, procedure, and surrounding video together rather than treating a printed result as self-validating.
Operator certification
The Department of Public Safety runs the Breath Alcohol Testing Program and certifies both the operator and the analysis under section 724.016. Certification status at the time of your test is a matter of record.
The full analysis information
Section 724.018 entitles you to full information about the analysis on request. That is a statutory right, not a favor, and it is one of the first things I ask for.
Your right to an independent test
Section 724.019 gives a person who submits to the officer's test the right to arrange an additional specimen, taken within two hours of arrest by a physician, qualified technician, chemist or registered nurse of your own choosing.
The independent test right, stated precisely
This right is widely described online and almost always described wrong, so it is worth being exact about what section 724.019 does and does not give you.
It applies to a person who submits to the officer's test. It is a right to an additional specimen, not a retest of the State's sample. Police are not required to transport you to obtain it. And a failed attempt to get one does not suppress the State's result.
Where a blood sample was taken by the State, retention is governed by Code of Criminal Procedure article 38.50, and that is the route to a retest, which is a different mechanism entirely from the additional specimen right.
Understanding which of those two applies to your case is not academic. They arise at different moments and produce different evidence.
Implied consent and the statutory warning
Section 724.011 sets out implied consent: by driving in Texas you are treated as having consented to a breath or blood specimen on arrest for an intoxication offense. That consent is not unconditional and it is not the end of the analysis.
Before a specimen is requested the officer must give the statutory warning, known as the DIC-24, under section 724.015. It has to be read aloud and provided in writing. It covers the consequences of refusal, the suspension lengths, the possibility of a warrant and the right to a hearing.
What was said, how it was said, and whether the written warning was actually provided are all questions the video usually answers. Where the warning was garbled, rushed or incomplete, the request that followed it is open to challenge.
Refusing carries its own consequences. It is admissible against you at trial under section 724.061, it triggers a longer license suspension, and since 2021 police can obtain a warrant and take blood anyway.
The refusal guide separates the officer's request, the statutory warning, a later warrant, specimen rules, and the 15-day license deadline.
If blood was drawn
Section 724.017 governs who may draw it and where: a physician, qualified technician, registered nurse, licensed vocational nurse or authorized paramedic, in a sanitary place.
Who drew it, whether they were qualified and where it happened are answerable questions, and each is part of the chain that has to hold.
Related pages
Blood test defense
Warrants, who may draw it, and the sample that still exists.
Field sobriety tests
The three tests, and why refusing them carries no license consequence.
DWI with a BAC of 0.15 or higher
A Class A charge, measured at the time of analysis rather than the time of driving.
Breath test questions
Does the Intoxilyzer measure my blood alcohol level?
No. It measures breath and converts to a blood figure using a fixed average ratio. That ratio is drawn from population data rather than measured from you, and people vary from it.
Can I get the records behind my test?
Yes. Section 724.018 entitles you to full information about the analysis on request, and operator certification under the DPS Breath Alcohol Testing Program is a matter of record under section 724.016.
I asked for my own test and was refused. Does that help me?
Not automatically. Section 724.019 gives a person who submitted the right to arrange an additional specimen within two hours, but police are not required to transport you, and a failed attempt does not suppress the State's result. What happened and why is still worth putting on the record.
What if the officer rushed through the warning?
The DIC-24 statutory warning under section 724.015 must be read aloud and given in writing before a specimen is requested. The video usually shows exactly how that was handled.
Should I have refused?
Refusal is not a free option. It carries a longer suspension, it is admissible at trial under section 724.061, and since 2021 a warrant can be obtained to take blood regardless. Whether it helped or hurt depends on the specific facts.