In Texas, driving while intoxicated (DWI) cases are common but incredibly complex. Defending against such charges requires deep knowledge of Texas laws, court precedents, and the science behind sobriety testing. With life-altering consequences on the line, from heavy fines to jail time, it’s vital to understand the most effective strategies for challenging the prosecution’s evidence in a DWI case. This article will cover some of the most critical aspects of Texas DWI defense, with a particular focus on field sobriety tests.

The Role of Evidence in Texas DWI Cases

Every DWI case hinges on the evidence presented by the prosecution. This evidence typically comes from several sources, including:

• Breathalyzer and blood test results
• Dashcam and bodycam footage
• Witness testimonies (including police officers)
• Field sobriety tests (discussed in detail below)

A well-prepared defense attorney will scrutinize each piece of evidence, looking for inconsistencies, procedural mistakes, and other issues that may lead to the dismissal of charges or a reduced sentence.

Challenging the Breathalyzer Results

One of the most common pieces of evidence in a Texas DWI case is the result of a breathalyzer test. Despite the reliance placed on these devices, breathalyzers are not foolproof. Several factors can result in false positives, such as:

• Calibration issues: Breathalyzer devices must be properly calibrated at regular intervals. If the device used in your case was not calibrated correctly, its results could be challenged.
• Medical conditions: Conditions like acid reflux or diabetes can influence the amount of alcohol detected in the breath, leading to misleading results.
• External factors: Mouthwash, certain foods, and even environmental conditions can skew breathalyzer results.

By raising questions about the reliability of breathalyzer results, a DWI defense attorney can weaken the prosecution’s case.

Blood Alcohol Content (BAC) Testing: Not Always Conclusive

Blood tests are often considered more accurate than breath tests, but they, too, have their limitations. Errors in the collection, handling, and storage of blood samples can compromise their reliability. A skilled DWI defense attorney will examine whether:

• Proper chain of custody was followed for the blood sample
• The blood sample was contaminated
• The person drawing the blood was qualified to do so
• Delays between the time of arrest and testing may have influenced the BAC results

Examining the Role of Dashcam and Bodycam Footage

In many Texas DWI cases, the arresting officer’s dashcam or bodycam footage will be used as evidence. This footage provides valuable insight into how the traffic stop was conducted, how the driver behaved, and how sobriety tests were administered. However, this footage can be beneficial to the defense if:

• It shows the officer did not follow proper procedures
• There are inconsistencies between the officer’s testimony and the video evidence
• It reveals that the driver’s behavior was not consistent with being intoxicated

Field Sobriety Tests: How a DWI Defense Attorney Will Challenge Them

Field sobriety tests (FSTs) are commonly used in Texas DWI arrests, but they are far from reliable. There are three standardized field sobriety tests typically used:

1. Horizontal Gaze Nystagmus (HGN): This test involves tracking the movement of the suspect’s eyes as they follow an object, typically a pen or flashlight, from side to side. Officers look for involuntary jerking of the eyes, which is thought to be a sign of intoxication. However, several factors can affect the results, such as medical conditions, fatigue, or the use of certain medications.
2. Walk-and-Turn Test: In this test, the suspect is asked to walk heel-to-toe in a straight line, turn, and walk back. This test is designed to assess balance and coordination. However, external factors such as uneven terrain, poor lighting, or the suspect’s footwear can lead to inaccurate results. Moreover, some individuals may have physical disabilities or conditions that make this test particularly challenging, even when sober.
3. One-Leg Stand Test: This test requires the suspect to stand on one leg while counting out loud. Again, factors like uneven ground, the weather, or the driver’s general fitness can lead to failure, even if they are not impaired.

Each of these tests has inherent flaws, and a skilled DWI defense attorney will focus on these weaknesses. They will challenge:

• The environment in which the test was administered (e.g., uneven ground, poor lighting)
• The physical condition of the driver (e.g., injuries, balance issues)
• Whether the officer followed the correct protocol when administering the test
• Whether the officer’s subjective interpretation of the test was fair

The Role of Expert Testimony in Challenging FSTs

In some DWI cases, it may be beneficial to call on expert witnesses, such as medical professionals or forensic toxicologists, to explain why the results of field sobriety tests or breathalyzers may not be accurate. These experts can provide alternative explanations for the observed behavior or test results, further undermining the prosecution’s case.

Scrutinizing the Traffic Stop: Was It Legal?

Before any evidence is even considered, the legality of the initial traffic stop must be assessed. In Texas, police officers need a reasonable suspicion to stop a driver. Common reasons for a stop include:

• Swerving or erratic driving
• Running a red light or stop sign
• Speeding or driving too slowly

If the officer did not have reasonable suspicion, any evidence collected after the stop—including breathalyzer results, field sobriety tests, and blood tests—could be inadmissible in court. This is often referred to as a “fruit of the poisonous tree” argument, where evidence obtained illegally cannot be used against the defendant.

Questioning Officer Conduct and Procedures

Police officers are required to follow specific procedures when conducting a DWI investigation. Failing to adhere to these protocols can be grounds for dismissal of evidence. For example:

• Failure to read Miranda rights: While the reading of Miranda rights is not required at the time of arrest, failure to do so before interrogation can lead to the exclusion of statements made by the defendant.
• Improper administration of field sobriety tests: As noted above, failure to follow standardized protocols when administering FSTs can render them invalid.

A thorough review of the arrest report, bodycam footage, and police testimony can reveal whether the officer acted in accordance with the law.

Refusing a Breathalyzer or Blood Test: Consequences and Defenses

Texas has an implied consent law, which means that by driving on Texas roads, you agree to submit to chemical testing if lawfully arrested for a DWI. Refusing to submit to a breathalyzer or blood test can result in automatic license suspension, but it’s not an admission of guilt. A DWI defense attorney can argue that:

• The refusal does not prove intoxication
• The officer did not explain the consequences of refusal adequately
• The driver was confused or under duress

In some cases, the refusal itself can be challenged, especially if the officer failed to follow proper procedure.

Challenging the Timing of Tests and Evidence

The timing of tests and the collection of evidence play a significant role in the reliability of DWI charges. Alcohol absorption and elimination rates vary between individuals, and delays between the time of driving and the time of testing can skew results. An experienced DWI attorney will question:

• How long after the traffic stop or arrest the breath or blood test was administered
• Whether the driver’s BAC may have been rising or falling at the time of the test
• Whether external factors, such as food intake, could have impacted the results

Texas DWI Penalties and Consequences

Although this article doesn’t cover the criminal case process or defenses, it’s essential to briefly touch on the penalties that may follow a DWI conviction. In Texas, these penalties can include:

• First Offense: Fines up to $2,000, up to 180 days in jail, and a license suspension of up to one year.
• Second Offense: Fines up to $4,000, up to one year in jail, and a license suspension of up to two years.
• Third Offense: Fines up to $10,000, two to ten years in prison, and a license suspension of up to two years.

These consequences make it clear why challenging the prosecution’s evidence is so crucial in every Texas DWI case.

Schedule Your Free Consultation Today

A DWI charge can have serious consequences, but with the right legal representation, you can fight to protect your rights and future. Let us provide the expert defense you need to navigate the complexities of DWI charges and work towards a favorable resolution.

A Texas DWI conviction can have a lasting impact on many aspects of your life, but understanding these consequences and knowing how to mitigate them can make a significant difference. The Law Office of Alex Tyra, P.C. is dedicated to providing the support and legal expertise you need during this challenging time. Contact us at (903) 753-7499 to discuss your case and explore your options for defense. Our experienced team is here to help you navigate this difficult journey and protect your future.