You are driving home in Denton when police lights appear. After pulling over, the officer asks you to step out for “standard” tests supposedly to check if you are safe to drive. At that moment, most people feel compelled to comply.
Do not trust that these roadside gymnastics are reliable indicators of intoxication. In reality, these tests are subjective, challenging even for sober individuals, and prone to error. Recognize the flaws in these tests as your first weapon in building a defense. When searching for DUI lawyers in Texas, know precisely the weaknesses in the evidence the state intends to use against you.
The Three Standard Tests Used in Denton
Police officers in Texas typically rely on three specific tests validated by the National Highway Traffic Safety Administration (NHTSA). These are collectively known as the Standardized Field Sobriety Tests (SFSTs).
Horizontal Gaze Nystagmus (HGN)
This test looks at your eyes. The officer will hold a pen or light in front of your face and ask you to follow it with your eyes without moving your head. They are looking for “nystagmus,” which is an involuntary jerking of the eyeball. The theory is that alcohol causes this jerking to become more pronounced or occur at lesser angles.
Walk-and-Turn
This is a divided attention test. You are asked to take nine heel-to-toe steps along a straight line, turn in a specific manner, and take nine heel-to-toe steps back. You must count out loud and keep your arms at your sides. The officer is watching for things like stepping off the line, using arms for balance, or starting too soon.
One-Leg Stand
In this test, you must stand with one foot approximately six inches off the ground and count aloud for thirty seconds. The officer looks for swaying, hopping, putting your foot down, or using your arms to balance.
Why “Standardized” Doesn’t Mean “Accurate”
The term “standardized” requires that these tests be administered in the same manner each time. It does not ensure they are accurate indicators of impairment. You must be aware that many factors can lead a sober person to perform poorly on these tests.
- Physical Conditions: Knee injuries, back problems, or inner ear issues can affect balance. Being overweight or elderly can make the One-Leg Stand nearly impossible, regardless of alcohol consumption. Even wearing high heels or boots can throw off your results on the Walk-and-Turn.
- Environmental Factors: Denton roads are not always perfectly flat or well-lit. Performing balance tests on a sloped shoulder of the road, in gravel, or under the strobing lights of a police cruiser creates a difficult environment. The distraction of passing traffic alone can cause someone to lose concentration.
- Nervousness: Anxiety mimics intoxication. When an officer with a gun and a badge is analyzing your every move, it is natural to shake, forget instructions, or speak in a rushed manner. Officers often misinterpret this natural fear as signs of guilt or impairment.
The Problem with the HGN Eye Test
The Horizontal Gaze Nystagmus test is often presented by prosecutors as the most scientific of the three. But nystagmus can be caused by dozens of conditions unrelated to alcohol.
Fatigue, high blood pressure, eye strain, and excessive caffeine consumption can all contribute to nystagmus. Even the strobe lights from the police car can affect the eyes. Furthermore, officers sometimes administer the test incorrectly by moving the stimulus too fast or holding it too high. Without a video recording that clearly shows your eyes, the evidence often comes down to just the officer’s word against yours.
Are You Required to Take These Tests in Texas?
There is a common misconception that you must take field sobriety tests. In Texas, field sobriety tests are voluntary.
Texas law regarding “implied consent” (Texas Transportation Code Chapter 724) applies to chemical tests, such as breath or blood tests, after you have been arrested. It does not apply to the roadside exercises before an arrest. You can politely decline to perform the eye test, the walk-and-turn, or the one-leg stand.
Refusing these tests prevents the officer from gathering that specific evidence against you. But realize that the officer can still arrest you if they believe they have other probable cause, such as the smell of alcohol, slurred speech, or your driving behavior.
The Advantage of a Forensic Lawyer Scientist
Challenging these tests demands more than legal knowledge. It demands scientific expertise. Having a designated Forensic Lawyer Scientist on your side gives you a decisive advantage.
I have undergone rigorous training to understand the science behind blood testing, toxicology, and the physiology of impairment. I know how to analyze the data and the police body camera footage to determine what really happened.
I can identify when an officer fails to follow the NHTSA manual. If the officer moves the pen too fast during the eye test, the results may be invalid. If they did not explain the instructions for the turn correctly, the “clues” they recorded against you might be worthless.
Interpreting this evidence accurately requires a thorough understanding of human biology and physics. I leverage this knowledge to cross-examine officers and demonstrate to a jury that a “failed” test does not equate to intoxication.
Looking Beyond the Police Report
Police reports are written to justify an arrest. They rarely contain information that helps your defense. That is why I take a personalized approach to every case.
We need to look at your medical history. Do you have old sports injuries? Do you suffer from vertigo? We also look at the scene of the arrest. Was the ground uneven? Was it windy or raining?
By combining a detailed personal history with a scientific analysis of the arrest video, we can often dismantle the prosecution’s reliance on these field sobriety tests. We dig deeper because your future is worth the effort.
What to Do If You Were Arrested
If you have already been arrested and performed these tests, do not panic. Poor performance does not guarantee a conviction. It means it is time to take strong, deliberate action.
The first step is preserving evidence. We need to secure the dashcam and bodycam footage before it is deleted. We need to review the offense report and check the officer’s certification status.
You need legal counsel who is available to answer your questions when you have them. I provide my personal cell phone number to clients because I know anxiety does not keep office hours. You can call or text me when you need reassurance or have a question about your case.
Fighting for Your Future in Denton
A DWI charge in Denton County is serious, but it is not the end of the road. The “evidence” gathered on the side of the road is often much weaker than the state wants you to believe. By challenging the validity of field sobriety tests, we can erode the prosecution’s case.
Whether you are a student at UNT or TWU, a professional, or a parent, a conviction can have lasting consequences. You deserve a defense that is compassionate, thorough, and scientifically sound.
If you are looking for DUI lawyers in Texas who offer a unique blend of scientific expertise and personalized care, I am here to help. I have spent 28 years defending the rights of Texans, and I am ready to put that experience to work for you. Do not face the legal system alone. Call me at 940-353-1334 to discuss your case.
