Exploring Common Defenses in Texas DUI Cases: What You Need to Know

Getting pulled over for suspected drunk driving is one of the most stressful experiences a person can face. Your heart races, the officer’s flashlight shines in your eyes, and suddenly you’re asked to step out of the car. Before you know it, you’re in handcuffs. It might feel like a done deal—but in reality, there are multiple defenses for DUI cases Texas courts will consider. And they’re more common—and more effective—than most people realize.

In this detailed guide, we’ll break down the most strategic defenses for DUI cases Texas attorneys use to protect their clients. Whether you blew just over the legal limit, refused a breath test, or were accused of driving under the influence of prescription drugs, there may be a path forward. We’ll explain each defense in plain language, share real-life examples, and show you how law enforcement mistakes, medical conditions, or even faulty equipment could be your best chance at beating a DUI charge in Texas.

What Counts as a DUI in Texas?

A Quick Legal Overview Before Exploring Defenses

Before we jump into defenses for DUI cases Texas attorneys use, let’s clarify what exactly a DUI (or DWI) means under Texas law.

In Texas, the official term is DWI—Driving While Intoxicated, defined under Texas Penal Code § 49.04. You can be arrested if:

• Your blood alcohol concentration (BAC) is 0.08% or higher
• You are impaired by drugs or alcohol, even if your BAC is below 0.08%
• You have any detectable alcohol if you’re under 21 (DUI for minors)

The penalties can be steep: jail time, thousands in fines, license suspension, mandatory ignition interlock devices, and a permanent criminal record.

But here’s the key: just because you were charged doesn’t mean you’ll be convicted. That’s where understanding defenses for DUI cases Texas comes into play.

The Traffic Stop Was Unlawful

Challenging the Legality of the Stop

One of the first and most powerful defenses for DUI cases Texas lawyers examine is whether the officer had a valid reason to pull you over in the first place.

Police must have reasonable suspicion to initiate a stop—such as swerving, speeding, or running a red light. If the officer pulled you over without cause, any evidence collected afterward—like breath tests or field sobriety results—may be thrown out under the exclusionary rule.

Real-life example: A woman in Fort Worth was stopped at 2 AM just for “driving late at night.” Her attorney argued there was no legitimate reason to pull her over, and the judge agreed. The case was dismissed before trial. This is one of the most effective defenses for DUI cases Texas courts recognize—if the stop is bad, the case can fall apart.

Improperly Administered Field Sobriety Tests

When the Tests Fail the Test

Field sobriety tests like the one-leg stand, walk-and-turn, and horizontal gaze nystagmus are notoriously unreliable. They must be administered exactly by the book according to National Highway Traffic Safety Administration (NHTSA) standards.

Common problems that make this one of the go-to defenses for DUI cases Texas defense attorneys use:

• The officer gave unclear instructions
• You have a medical condition (like vertigo or knee injury)
• No dashcam footage to verify what happened
• Uneven pavement or poor lighting skewed the results

Example: A man in Austin failed the walk-and-turn test but had a leg brace. His attorney used medical records and bodycam inconsistencies to argue the test was meaningless. The judge suppressed the field test results, and prosecutors offered a reduced charge.

Breathalyzer Malfunctions and Calibration Issues

Technology Isn’t Always Right

Breath testing devices can be sensitive, prone to errors, and even improperly calibrated. This makes challenging breathalyzer results one of the strongest defenses for DUI cases Texas has available.

Strong defense points:

• The device was overdue for calibration
• The officer wasn’t certified to use it
• Mouth alcohol (from burping,acid reflux, or dental work) skewed the reading
• You used mouthwash or medication before the test

A qualified defense attorney can subpoena maintenance logs, officer training records, and expert witnesses to challenge the device’s accuracy.

Rising Blood Alcohol Defense

The “I Wasn’t Over the Limit While Driving” Argument

Here’s a lesser-known but clever strategy among defenses for DUI cases Texas lawyers: the rising BAC defense.

Alcohol takes time to absorb into the bloodstream. If you had a few drinks and drove home immediately, your BAC may have been below 0.08% while driving but higher by the time you were tested later.

This defense is especially useful when:

• There’s a delay between the stop and the breath test
• You showed no signs of intoxication while driving
• You consumed alcohol just before leaving the bar or restaurant

Example: A college student in Houston was pulled over 30 minutes after leaving a bar. His BAC registered at 0.09%. Expert testimony showed his BAC was likely under the legal limit when he was driving. The jury found him not guilty.

Medical Conditions That Mimic Intoxication

Don’t Judge a Book by Its Symptoms

Many conditions can mimic the appearance of intoxication, including:

• Diabetes (hypoglycemia or ketoacidosis)
• Epilepsy
• Neurological disorders
• Eye injuries
• Fatigue or anxiety

If you have a medical condition that explains your symptoms, this can be a compelling component of defenses for DUI cases Texas lawyers present in court.

In some cases, even breathalyzer tests can be affected. For example, diabetics experiencing ketoacidosis can produce acetone, which may cause a false positive on some breath tests.

No Proof of Impairment Beyond the Test

The BAC Isn’t Everything

While breath or blood tests are key evidence, they aren’t always enough to prove someone was impaired. Prosecutors still have to show you were actually driving impaired, especially in drug-related DUI cases.

This gives defense attorneys another angle: no clear signs of impairment.

Helpful facts in this defense:

• No erratic driving captured on dashcam
• Normal behavior and speech in bodycam footage
• Passing most field tests
• No drugs or alcohol found in the vehicle

Even if your BAC was over 0.08%, your lawyer might argue that the state failed to prove actual impairment, one of the key defenses for DUI cases Texas courts may consider.

Illegal Arrest or Miranda Violations

Your Rights Weren’t Respected

Under Texas law, you must be informed of your rights after arrest—especially before any custodial interrogation. If the officer failed to read you your Miranda rights, any statements you made may be inadmissible in court.

Additionally, if you were held too long without probable cause or weren’t allowed to contact an attorney, those violations can become powerful defenses for DUI cases Texas lawyers can leverage to reduce or dismiss charges.

DUI Charges Based on Drug Use (DUID)

Challenging Drug Recognition and Testing

Driving under the influence of drugs (legal or illegal) is treated similarly to alcohol DUIs in Texas. But proving drug impairment is much harder, making drug-related DUI defenses an important category of defenses for DUI cases Texas attorneys rely on.

Challenges include:

• Lack of a Drug Recognition Expert (DRE) at the scene
• Inconclusive or delayed blood test results
• No field sobriety tests tailored to drug impairment
• Legal use of prescribed medications

Because drug impairment is harder to measure, juries often side with defendants when evidence is weak or contradictory.

Necessity or Emergency Defense

When You Had No Other Choice

This defense is rare but powerful when applicable. If you drove under the influence because of a genuine emergency—like escaping a dangerous situation or rushing someone to the ER—you might have a valid necessity defense.

Texas law recognizes that in emergencies, people sometimes act outside the law to prevent greater harm. This unique angle is occasionally used in defenses for DUI cases Texas judges hear, especially when no one was hurt, and the intent wasn’t malicious.

Real-Life Case Spotlight: DUI Charges Dropped After Strategic Defense

When Legal Strategy Makes All the Difference

Carlos, a 42-year-old Army veteran from San Antonio, was pulled over after leaving a sports bar. His BAC tested at 0.082%. Initially, it looked like a conviction was inevitable. But his attorney dug deeper.

They discovered:

• The breathalyzer hadn’t been calibrated in over six weeks
• Carlos had acid reflux, which likely caused a false BAC reading
• Dashcam footage showed he drove smoothly and obeyed traffic laws

The defense attorney filed a motion to suppress the breath test and succeeded. With the key evidence excluded, the prosecution dropped the case.

This is a textbook example of how defenses for DUI cases Texas courts acknowledge can truly change the outcome.

Final Thoughts on Defenses for DUI Cases Texas

Just because you’ve been arrested for DWI in Texas doesn’t mean you’re guilty—or that you’ll be convicted. Every DUI case is different, and each presents an opportunity to challenge the evidence, the procedure, or the assumptions made by law enforcement.

Whether it’s an illegal stop, a flawed breath test, or a medical condition, defenses for DUI cases Texas attorneys use are rooted in real law, real precedent, and real human experience. With the right legal strategy and early intervention, you can fight back against DUI charges—and win.