A DWI charge in Texas can have life-altering consequences, and breath test results are often the prosecution’s key evidence. But breath tests are not always accurate and can be challenged based on calibration errors, improper administration, and officer conduct. Working with an experienced Dallas DWI Defense Lawyer is critical to protecting your rights and your future.
At the Law Offices of Richard C. McConathy, we’ve spent over 35 years successfully challenging breath test evidence and helping clients avoid harsh penalties. We offer free consultations to evaluate your case and identify the strongest defense options.
Texas DWI Breath Test Laws: What You Need to Know
Understanding Texas DWI breath test laws is essential if you’ve been arrested or suspect you may be facing charges. These laws govern when officers can request breath tests, your obligations as a driver, and the potential consequences of your choices.
What is a Breath Test?
A breath test, commonly administered using a breathalyzer device, measures the amount of alcohol in your breath to estimate your blood alcohol concentration (BAC). Texas law enforcement uses two primary types:
Portable Breath Test (PBT) devices are handheld units used during roadside traffic stops for preliminary screening. These help officers establish probable cause for arrest but are generally not admissible in court due to lower accuracy.
Intoxilyzer machines are sophisticated stationary devices at police stations used after arrest. These evidential breath tests produce results admissible in criminal proceedings and undergo more rigorous calibration and maintenance protocols.
Texas Implied Consent Law
Texas’s “implied consent” law requires all drivers lawfully arrested for DWI to submit to chemical testing. By obtaining a Texas driver’s license, you automatically consent to these tests when suspected of impaired driving.
Key requirements:
- Submit to chemical testing after lawful arrest for DWI
- Officers choose which type of test to administer
- Refusal carries automatic penalties separate from criminal charges
Officers must inform you of specific consequences before requesting a chemical test, including that refusal will result in license suspension, jail time upon conviction, and that refusal can be used against you in court.
Can You Refuse a Breath Test in Texas?
Yes, you can refuse a breath test in Texas, but this decision comes with serious consequences. Understanding the distinction between different types of refusals is crucial for making an informed choice.
Refusing at the Scene vs. Post-Arrest
Before arrest, you have the right to refuse preliminary breath tests (PBTs) conducted at the roadside. These refusals typically don’t result in immediate license suspension.
After arrest, Texas’s implied consent law requires submission to chemical testing. Refusal triggers automatic administrative penalties separate from criminal charges.
Situations where refusal may not be an option:
- Cases involving serious injury or death
- Multiple prior DWI convictions
- DWI arrests with passengers under 15 years old
- “No Refusal” enforcement periods when officers can obtain warrants quickly
ALR Hearings and License Suspension
Administrative License Revocation (ALR) hearings are civil proceedings separate from criminal court that determine whether your driving privileges will be suspended. Refusing a chemical test when requested triggers immediate suspension.
Critical timeline: You have only 15 days from arrest to request an ALR hearing. Missing this deadline results in automatic maximum suspension.
The hearing allows you to challenge the legality of the stop, arrest circumstances, and technical aspects of test refusal. At the Law Offices of Richard C. McConathy, we represent clients in ALR hearings throughout Texas, often identifying procedural errors that lead to license reinstatement.
Are DWI Breath Tests Accurate in Texas?
While prosecutors often present breath test results as infallible evidence, these devices have significant limitations and can produce inaccurate readings under various circumstances.
Problems with Breathalyzer Accuracy
Breath testing technology relies on scientific assumptions that don’t always reflect individual physiology or real-world conditions. Several factors can compromise accuracy:
Medical conditions affecting results:
- GERD and acid reflux: Stomach contents returning to the mouth can bring trace amounts of alcohol
- Diabetes: Produces acetone that machines may misread as alcohol
- Ketosis from low-carb diets: Can produce compounds some devices interpret as alcohol
Environmental and physiological factors:
- Recent use of mouthwash or breath spray
- Residual alcohol from burping or belching
- Body temperature variations affecting alcohol vaporization
- Breathing patterns and lung capacity differences
Temperature significantly impacts results because higher body temperature increases alcohol diffusion from blood to lungs. Machines assume a standard body temperature of 34 degrees Celsius.
Portable vs. Stationary Machines
Portable Breath Test (PBT) devices:
- Used during roadside investigations
- Less accurate than stationary units
- Results typically not admissible in court
- Serve primarily to establish probable cause
Stationary Intoxilyzer machines:
- Located at police stations and jails
- Subject to rigorous calibration requirements
- Produce admissible evidence in criminal trials
- Still susceptible to various accuracy problems despite stricter protocols
Challenging BAC Results in Court
Successfully challenging breath test results requires understanding both scientific and legal aspects:
Technical reliability issues:
- Improper calibration or maintenance
- Missing calibration records
- Software malfunctions or hardware problems
- Lack of proper certification
Procedural violations:
- Failure to observe required waiting periods
- Inadequate operator training
- Improper test administration
- Contamination of breath samples
Legal Defenses Against DWI Breath Test Results
At the Law Offices of Richard C. McConathy, we employ comprehensive strategies to challenge breath test evidence, often achieving favorable outcomes even when initial BAC readings exceed the legal limit.
Procedural Errors by Law Enforcement
Police officers must follow specific protocols when administering breath tests. Any deviation can compromise result validity.
Common procedural errors:
- Failing to observe required observation periods
- Not properly explaining implied consent warnings
- Inadequate training or expired certifications
- Improper documentation
Officers must be certified to administer tests, observe a 15-minute waiting period, and follow strict protocols. Failure to meet these requirements can result in successful challenges.
Improper Calibration or Maintenance
Breathalyzers must be routinely calibrated by licensed technicians. The prosecution must provide this information to the defense.
Calibration requirements:
- Regular accuracy checks by certified technicians
- Complete documentation of maintenance activities
- Replacement of worn components
- Adherence to manufacturer specifications
Missing or inadequate calibration records can render breath test results inadmissible in court.
Rising BAC Defense
The rising BAC defense challenges the assumption that your BAC at the time of testing reflects your BAC while driving. Since alcohol absorption continues after consumption, your BAC may have been below the legal limit while driving but above it during testing.
Key factors in rising BAC defense:
- Time elapsed between driving and testing
- Pattern and timing of alcohol consumption
- Individual metabolism and absorption rates
- Food consumption and other mitigating factors
Constitutional Violations
Fourth Amendment protections against unreasonable searches and seizures apply to DWI investigations. If officers violated your constitutional rights, evidence obtained through that violation may be suppressed.
Constitutional challenges include:
- Illegal traffic stops without reasonable suspicion
- Searches conducted without proper warrant or consent
- Coerced consent to testing
- Failure to provide required warnings
Penalties for Refusing a Breath Test in Texas
Understanding the specific penalties for breath test refusal helps you make informed decisions during a DWI investigation.
First-Time Refusal
First-time chemical test refusal results in 180 days of license suspension. This administrative penalty occurs regardless of ultimate DWI conviction.
Additional consequences:
- Refusal evidence can be used in court
- No occupational license eligibility during suspension
- Separate criminal charges may still be filed
Repeat Refusals and Enhanced Penalties
Two years of license suspension applies if you have any alcohol or drug-related “enforcement contact” within the last ten years.
Enhanced penalties may include:
- Extended suspension periods
- Ignition interlock device requirements
- Increased fines and court costs
- Mandatory alcohol education programs
Commercial Driver Refusal Consequences
Commercial drivers face additional penalties under federal regulations:
- One-year disqualification for first refusal
- Lifetime disqualification for second refusal
- Loss of commercial driving privileges affects employment
- Standard driver’s license may also be suspended
| Offense Type | First Refusal | Subsequent Refusal |
|---|---|---|
| Regular License | 180 days | 2 years |
| CDL Disqualification | 1 year | Lifetime |
| Criminal Penalties | Separate charges possible | Enhanced penalties |
What to Do After Failing or Refusing a Breath Test
Taking immediate action after a breath test failure or refusal is crucial for protecting your rights and minimizing consequences.
Request an ALR Hearing Immediately
You must request an ALR hearing within 15 days to contest automatic license suspension.
Critical deadlines:
- ⏰ 15 days to request ALR hearing from arrest date
- Written request required with proper forms
- Failure to request results in automatic maximum suspension
- Attorney representation significantly improves success rates
Contact an Experienced Texas DWI Attorney
DWI laws and breath test science require experienced legal representation. Our team has successfully handled thousands of DWI cases across Texas.
Why experience matters:
- Understanding of technical breath test issues
- Knowledge of successful challenge strategies
- Relationships with expert witnesses and toxicologists
- Familiarity with local prosecutors and judges
We handle related charges like field sobriety test violations and felony DWI charges in Texas.
Preserve Your Rights and Evidence Early
Time-sensitive evidence can make or break your case:
- Security camera footage from arrest location
- Witness statements about your condition
- Medical records related to conditions affecting test results
- Documentation of circumstances surrounding your arrest
Protect yourself by:
- Avoiding statements to police without attorney present
- Documenting any medical conditions or medications
- Gathering contact information for potential witnesses
- Preserving evidence of recent food or drink consumption
How Our Texas DWI Lawyers Can Help You
At the Law Offices of Richard C. McConathy, we bring over three decades of DWI defense experience to every case. Our comprehensive approach addresses both the technical and legal aspects of breath test challenges.
Case Evaluation and Strategy Development
Every case requires thorough analysis of evidence and circumstances:
- Technical aspects: Calibration records, maintenance logs, operator certifications
- Legal issues: Constitutional violations, procedural errors, evidence admissibility
- Scientific challenges: Medical conditions, environmental factors, timing issues
- Witness testimony: Police reports, civilian witnesses, expert testimony
Representation at ALR Hearings
Our attorneys represent clients in Administrative License Revocation hearings throughout Texas, challenging:
- Legality of the initial traffic stop
- Proper administration of implied consent warnings
- Technical reliability of testing equipment
- Officer training and certification issues
Suppression Motions and Evidence Review
We file aggressive motions to suppress evidence when:
- Constitutional rights were violated during the stop or arrest
- Breath test procedures were improperly followed
- Equipment was not properly maintained or calibrated
- Chain of custody issues compromise evidence integrity
Negotiation and Trial Representation
When cases proceed to trial, our experience with Texas courts and understanding of breath test science proves invaluable in developing effective defense strategies.
Our team regularly challenges breath test evidence through various legal strategies, including motions to suppress evidence when constitutional violations occur during traffic stops.
Call our attorneys today at (972) 528-0478 for a free consultation to discuss how we can challenge your breath test results and protect your future.
FAQs About Breath Tests in Texas
What happens if you refuse a breath test in Texas?
Refusing a chemical test when requested by law enforcement results in immediate license suspension. First-time refusals face 180-day suspension, while subsequent refusals result in two-year suspensions. Additionally, your refusal can be used as evidence in criminal court.
Can a breath test be wrong?
Yes, breath tests can produce inaccurate results due to various factors including medical conditions like diabetes or GERD, recent use of mouthwash, environmental contaminants, and improper device maintenance. These factors can be challenged in court to dispute BAC results.
How long do I have to request an ALR hearing in Texas?
You have exactly 15 days from your arrest date to request an Administrative License Revocation hearing. This deadline is absolute – missing it results in automatic license suspension for the maximum allowable period. The request must be made in writing to the Texas Department of Public Safety.
Can you beat a DWI if you fail a breath test?
Yes, it’s possible to successfully defend against DWI charges even with a failed breath test. Success depends on factors like proper equipment calibration, procedural compliance, constitutional issues, and alternative explanations for elevated BAC readings. Effective legal representation is crucial for challenging evidence and achieving favorable outcomes.
What medical conditions can affect breath test results?
Several medical conditions can impact breathalyzer accuracy:
- Diabetes: Produces acetone that machines may misread as alcohol
- GERD/Acid Reflux: Causes stomach contents to enter the mouth, potentially increasing readings
- Asthma: Recent inhaler use can affect results
- Ketosis: From low-carb diets, produces acetone compounds
Can I get an occupational license after breath test refusal?
License reinstatement options depend on the specific circumstances of your case. Generally, first-time refusals result in suspension periods without occupational license eligibility. However, various factors may affect your eligibility, and experienced legal representation can help explore all available options.