Charged with DWI Over .15 BAC in Dallas? Fight Enhanced Class A Misdemeanor Charges

If your blood alcohol level was reported at .15 or higher, Texas law automatically enhances your DWI charge to a Class A misdemeanor—exposing you to increased jail time and fines. In Dallas, a DWI over .15 BAC can carry up to 1 year in jail and $4,000 in fines, compared to a standard first DWI. But the number alone doesn’t end the case.

Breath and blood tests are often challenged—and results over .15 can be caused by testing errors, improper procedures, or unreliable equipment. At the Law Offices of Richard C. McConathy, we’ve defended hundreds of DWI cases and know how to break down BAC evidence and challenge enhanced charges.

If you’re facing a DWI over .15, working with an experienced DWI lawyer Dallas can make a critical difference in how your case is handled.

Understanding DWI Over .15 BAC Under Texas Law

The Statute: Texas Penal Code §49.04(d)

Texas Penal Code §49.04(d) defines DWI with BAC of .15 or higher as an enhanced offense:

(d) The defendant’s BAC at the time of the offense was 0.15 or more.

This single statutory factor elevates the charge from Class B misdemeanor to Class A misdemeanor. No additional proof is required—only that your BAC was .15 or above. The enhancement applies to:

• First-time DWI offenses (becomes Class A instead of Class B)
• Second offenses (increases prison range from 6 months to 1 year)
• Third or subsequent offenses

Class A Misdemeanor Penalties

• Standard DWI (first offense): Class B misdemeanor, up to 180 days jail, up to $2,000 fine
• DWI over .15 (first offense): Class A misdemeanor, up to 1 year (365 days) jail, up to $4,000 fine

That’s 185 additional days in potential jail time and $2,000 additional fine exposure—all based on a single test result.

License Suspension and Collateral Consequences

Beyond criminal penalties, DWI over .15 results in:

• Mandatory 1-year driver’s license suspension (compared to 90 days for standard DWI)
• DPS Surcharge: Up to $2,000 per year for 3 years (additional $6,000 total cost)
• Ignition Interlock Device (IID) requirement: You must install a device on your vehicle preventing ignition if breath alcohol is detected. IID installation and monthly monitoring costs $75-$150 per month.
• Alcohol education programs: Mandatory DUI education and potentially substance abuse counseling
• Criminal record: A permanent misdemeanor record affecting employment, housing, and professional opportunities
  
  

Why BAC Over .15 Doesn’t Automatically Mean Guilt

The Problem with Breath Tests

Breathalyzer devices—typically Intoxilyzer 9000 machines used by Dallas police are not as reliable as many assume. Multiple factors can produce inflated BAC readings:

• Improper calibration. The machine must be calibrated according to strict Texas Department of Licensing and Regulation (TDLR) standards. Many machines are improperly calibrated or calibration records are incomplete.
• Faulty equipment. Machines malfunction, components wear out, and software glitches produce inaccurate results. We demand complete maintenance and repair records to identify equipment problems.
• Improper testing procedures. Texas law requires a 15-minute “mouth alcohol deprivation period” before breath testing—15 minutes during which you don’t eat, drink, burp, vomit, or regurgitate. If this procedure is skipped or shortened, residual mouth alcohol inflates BAC readings.
• Operator error. The officer administering the test must follow precise procedures. Deviations from protocol—improper breath sample collection, insufficient breath volume, or rushed procedures—produce unreliable results.
• Acid reflux and medical conditions. Gastroesophageal reflux disease (GERD), diabetes, and other conditions can elevate breath test results. Some people naturally produce higher BAC readings due to physiology, not intoxication.
• Partition ratio variation. Breath tests assume a precise ratio between breath alcohol and blood alcohol (1:2100). This ratio varies among individuals, sometimes producing inflated BAC estimates.
• Radio frequency interference. Electronic devices in the testing environment can interfere with machine accuracy.
• “Slope detection” defects. This Intoxilyzer feature detects whether the breath sample is increasing or decreasing. Defects in slope detection often invalidate test results.
  
  

The Problem with Blood Tests

Blood tests are generally more accurate than breath tests, but they too have significant flaws:

Chain of custody violations. The blood sample must be properly collected, labeled, stored in cool darkness, and transported to the lab. Any break in chain of custody compromises reliability.

Improper storage or preservation. Blood samples must contain sodium fluoride preservative and be stored properly. Contamination, improper temperature, or aging can inflate results through fermentation or bacterial growth.

Lab testing errors. The lab conducting blood analysis must use proper procedures, maintain equipment, and follow strict protocols. Lab errors, contamination, or misidentification of samples occur.

Improper collection technique. The phlebotomist drawing blood must follow proper procedures. Improper collection technique, contamination, or mixing of samples can result in inaccurate results.

Expert challenge. We retain certified toxicology experts to review blood test procedures, storage conditions, chain of custody, and testing methodology. These experts often identify errors affecting result reliability.

The Most Effective Defense: Challenge the Test Result

Demanding Discovery and Test Records

Our first action is demanding comprehensive discovery from the prosecution:

• BAC test result documentation
• Machine maintenance and calibration records (if breath test)
• Operator certification and training records
• Test procedures and step-by-step protocols followed
• Quality control records
• Any communication about machine problems or defects
• Lab accreditation documentation (if blood test)
• Chain of custody documentation (if blood test)
• Phlebotomist certification and training records (if blood test)
• Lab testing procedures and quality assurance protocols

Many agencies fail to produce complete records, which strengthens our arguments that tests were unreliable or improperly conducted.

Hiring Toxicology Experts

We retain certified toxicology experts who:

• Review all test procedures and identify deviations from protocol
• Analyze machine maintenance and calibration records
• Identify technical defects in breath test equipment
• Explain physiological and medical factors affecting BAC
• Testify about the unreliability of the government’s test results
• Provide alternative explanations for elevated readings

Expert testimony powerfully challenges BAC evidence and creates reasonable doubt about whether your BAC actually exceeded .15.

Filing Motions to Suppress or Exclude Test Results

We file aggressive motions arguing:

The test was administered improperly. Police violated NHTSA standards or Texas procedures, making the result unreliable.

The machine was defective. Maintenance records show equipment problems that invalidate the result.

The sample was improperly handled. Chain of custody violations (for blood tests) compromise reliability.

The operator was improperly trained or certified. The person administering the test lacked proper credentials.

Medical evidence contradicts the test result. Your medical condition, medications, or physiological condition explains the elevated reading without corresponding intoxication.

Many judges grant these motions, excluding the BAC evidence entirely. When the BAC result is excluded, prosecutors often reduce the charge to standard DWI or offer probation, eliminating the enhanced penalty.

Other Effective Defense Strategies

Challenging the Traffic Stop

Every DWI case begins with a traffic stop. If police lacked reasonable suspicion to stop your vehicle, all evidence obtained after the stop is suppressed and inadmissible. We file motions to suppress when:

• The officer observed no traffic violation or equipment defect
• The officer’s observations don’t constitute reasonable suspicion
• The officer prolonged the stop beyond its original purpose
• The stop was pretextual (really looking for drugs)

Attacking Sobriety Tests

Field sobriety tests are highly subjective and unreliable. We challenge:

• Improper administration or scoring
• Unfair testing conditions (poor lighting, uneven surface, traffic hazards)
• Medical conditions or medications affecting performance
• The officer’s bias or prejudgment

Questioning Police Conduct and Credibility

We thoroughly cross-examine arresting officers, exposing:

• Inconsistencies between their testimony and dash/body camera footage
• Deviations from DWI investigation procedures
• Gaps in their memory or documentation
• Bias or prejudgment about your guilt
  
  

What Happens in a Dallas DWI Over .15 Case

Arrest and Booking

You’ll be arrested, booked, and taken to a police station for BAC testing. The officer will likely inform you of the test result (e.g., “.18 BAC”) and explain the enhanced charge classification.

Don’t make any statements about the test result or your driving. Request an attorney immediately.

Administrative License Revocation (ALR) Hearing

You have 15 days from arrest to request an ALR hearing challenging your license suspension. This hearing is separate from criminal charges and gives us a critical opportunity to challenge the traffic stop and BAC test.

At the ALR hearing, we:

• Cross-examine the officer about the traffic stop
• Question the officer about BAC test procedures and compliance
• Argue that reasonable suspicion was lacking or procedures were improper
• Present evidence and testimony challenging BAC accuracy

If we win the ALR hearing, your license suspension is rescinded. Even if we lose, evidence gathered and testimony presented provides valuable ammunition for the criminal case.

Prosecutors’ Initial Offers

Early in the case, prosecutors typically offer a plea deal. First offers are often harsh—accepting jail time, large fines, and enhanced penalties. Don’t accept early offers. As our investigation develops and we challenge test reliability, prosecutors often improve their offers significantly.

Our Investigation and Motion Practice

We:

• Demand discovery of all police reports, video footage, and test records
• Retain toxicology experts to analyze BAC testing procedures
• Request maintenance and calibration records for breath test equipment
• Investigate the operator’s training and certification
• Gather medical evidence about conditions affecting BAC
• File motions to suppress evidence or exclude unreliable tests
• Prepare for trial with expert witness testimony

Often, BAC evidence is excluded during pre-trial motion practice, forcing prosecutors to reduce charges.

Plea Negotiations

With evidence of BAC test unreliability, we negotiate aggressively:

• Reduction from Class A to Class B misdemeanor (eliminating the enhancement)
• Reduction to “wet reckless” (reckless driving with alcohol involved, a non-DWI charge)
• Probation without jail time
• Diversion programs and case dismissal upon completion
• Case dismissal if BAC evidence is entirely excluded

Trial Preparation

If negotiations don’t produce favorable outcomes, we prepare for trial. Our strategy includes:

• Expert witness testimony about BAC test unreliability
• Cross-examination of the police officer
• Presentation of medical evidence
• Arguments emphasizing reasonable doubt about BAC accuracy

Common Mistakes in DWI Over .15 Cases

Mistake #1: Assuming the Test is Accurate

Many people assume breath and blood tests are infallible. They’re not. We successfully challenge BAC results regularly, proving they were unreliable or obtained improperly. Don’t accept the test result at face value.

Mistake #2: Accepting the Enhanced Charge Without Fighting

The enhancement from Class B to Class A is automatic, but the enhancement is based entirely on the BAC test. Challenge the test, and we eliminate the enhancement. Many defendants accept the enhanced charge and enhanced penalties without realizing the test could be challenged.

Mistake #3: Missing the 15-Day ALR Deadline

You have exactly 15 days from arrest to request an ALR hearing. Miss this deadline, and your license suspension becomes automatic. Contact our office immediately—don’t wait.

Mistake #4: Pleading Guilty to the Enhanced Charge

Don’t plead guilty to the enhanced charge without exhausting all options. We’ve secured charge reductions, dismissals, and favorable plea deals in countless cases where clients initially faced enhanced DWI charges.

Mistake #5: Failing to Demand Discovery

You have the right to demand complete discovery from prosecutors—all evidence, test records, and documents. Many agencies fail to produce complete records when properly demanded. Incomplete production strengthens our arguments that procedures were improper.

Why Your BAC Over .15 May Not Be Your Actual BAC

Physiological Explanations for Elevated Readings

Partition ratio variation. Breath tests assume all people have a 1:2100 breath-to-blood alcohol ratio. This assumption is false. Some people have ratios of 1:1700 to 1:2500, meaning their breath alcohol produces artificially high or low BAC estimates.

Auto-brewery syndrome. Some people’s bodies produce ethanol from carbohydrates internally, creating false BAC readings. This rare condition is documented in medical literature.

GERD and acid reflux. These conditions allow stomach alcohol to regurgitate into the mouth during breath testing, inflating readings with mouth alcohol rather than lung alcohol.

Mouth alcohol from mouthwash or breath products. Alcohol-containing products can create mouth alcohol during the mouth alcohol deprivation period if procedures aren’t followed perfectly.

Unabsorbed alcohol in the digestive system. If you recently consumed alcohol, your BAC continues rising as alcohol absorbs. A test taken while alcohol is still absorbing may show a higher BAC than when you were driving.

Medical conditions. Diabetes, hypoglycemia, and other conditions can produce elevated breath test readings.

Medications. Some medications contain alcohol or affect metabolism, producing elevated readings.

Immediate Action Steps

Step 1: Request an Attorney

After arrest, clearly state: “I want an attorney.” Don’t answer police questions or explain your actions.

Step 2: Contact Our Firm Immediately

Call 972-528-0116. We’ll discuss your situation, explain the enhanced charge, and discuss next steps.

Step 3: Authorize the ALR Hearing Request

We’ll file an ALR hearing request before your 15-day deadline expires. This hearing is critical.

Step 4: Authorize Investigation and Expert Retention

We’ll demand discovery, retain toxicology experts, and analyze BAC test procedures. This investigation often reveals test defects and supports BAC challenge.

Step 5: Prepare for Negotiations or Trial

We’ll negotiate aggressively with prosecutors, leveraging evidence of BAC test unreliability. If negotiation doesn’t produce favorable outcomes, we prepare for trial.

Why Our Firm for DWI Over .15 Defense in Dallas

Our firm has defended hundreds of DWI cases, including many enhanced DWI over .15 charges. We understand:

• Dallas DWI procedures and enforcement patterns
• Intoxilyzer machine operation and common defects
• BAC testing procedures and frequent errors
• Expert witness testimony and toxicology evidence
• Dallas prosecutors and judges handling DWI cases
• Effective negotiation strategies and trial tactics

We know how to challenge BAC evidence and often get cases dismissed or charges reduced. You don’t have to accept the enhanced Class A charge.

If you’ve been charged with DWI over .15 in Dallas, contact our office immediately. Call 972-528-0116 for a confidential consultation. Your case may be stronger than you think.