In Texas, field sobriety tests are conducted when a police officer pulls you over for any reason, and they suspect you are under the influence of drugs or alcohol. Clues of intoxication could be slurred speech, the smell of alcohol, bloodshot eyes, and confusion. They are also designed to divide your attention between mental and physical activities by asking questions or giving instructions during some physical activities to prove that you have lost the normal use of your physical or mental faculties.

Types of Standardized Field Sobriety Tests in Texas

Generally, there are three types of standard field sobriety tests that a Texas law enforcement officer might use to determine if you are intoxicated: One-Leg-Stand, Walk-and-Turn, and Horizontal Gaze Nystagmus (HGN). A testing officer must be currently certified to perform these tests and will have been trained to look for clues of intoxication to make a DWI determination. The officer must give exact instructions, or you could challenge the results of the tests on the grounds of reasonable doubt because the tests are only validated if an officer administers the test correctly with the exact instructions.

These field sobriety tests, also referred to as Standardized Field Sobriety Tests (SFSTs), are a means to assist the investigating officer in determining whether or not a person is intoxicated and should be arrested. Unlike a finding of guilt beyond a reasonable doubt at trial, less evidence is needed to make an arrest for a finding of probable cause. If the investigating officer judges that the public's safety is at risk, that can also play a part in making a DWI arrest. Since the arresting officer's judgment and observations might not be accurate, a good criminal defense attorney can successfully challenge the DWI charge and any evidence the prosecution has in your DWI case.

One-Leg-Stand Test

When implementing the one-leg-stand (OLS) test as part of the SFSTs, the officer will instruct you to count aloud as you lift one foot approximately six inches off the ground. Your arms will need to remain at your side. The officer is looking for clues of intoxication such as: swaying, hopping, using your arms to maintain balance, or putting your foot down on the ground before completion of the test.

What if you have physical limitations that affect your balance or have difficulties with your balance under normal conditions? You could end up failing the test, not because you are intoxicated but because of these pre-existing conditions, which could help raise reasonable doubt.

Walk-and-Turn Test

There are two parts to the walk-and-turn test. The first part is the instruction phase, where the officer will demonstrate how to perform the test, and the second part is the performance, where the individual will need to perform the test and follow the officer's instructions.

While keeping your arms at your side, you will need to take nine heel-to-toe steps along an imaginary line, then turn and take nine steps back. You will need to count the steps out loud as you take them.

The officer will be looking for clues of intoxication during this test, beginning with how well you listen to the instructions. Each time the officer administers the test, they must give them in precisely the same way. The officer is trained to look for the following clues of intoxication:

  • Starting the test before the officer has finished giving instructions
  • Stopping while walking on the imaginary line
  • Using the arms for balance while on the imaginary line
  • Stepping off the imaginary line
  • Turning incorrectly or taking the incorrect number of steps while on the imaginary line

Horizontal Gaze Nystagmus (HGN) Test

In the HGN test, also known as the “pen” or “eye” test, the officer will ask the individual to follow an object placed in front of them and follow it with their eyes. If the person is intoxicated, the involuntary “jerking” of the eyeball will become more exaggerated. The HGN is the third test given as part of the SFSTs.

Since nystagmus is a condition where you can't control your eye movement, the HGN test could cause a false positive result and result from a health condition and not intoxication.

Challenging Field Sobriety Tests in Texas

Since medical conditions and physical and mental states can affect the results of field sobriety tests, failing one is not necessarily an indication of intoxication as these tests are not 100 percent accurate. Contact your criminal defense attorney if you need to challenge the test results in your DWI case.

For instance, if you suffer a head injury from an automobile accident, you could likely fail any field sobriety tests if the investigating officer elects to administer one. Though police are trained not to administer these tests if a person shows signs of a concussion, mistakes can happen. When administering the one-leg-stand test, both the elderly and overweight individuals could have trouble performing it without failing the test – despite not being intoxicated.

Road Conditions and Traffic

Even road conditions can affect the results of a walk-and-turn test. Uneven conditions in the road can affect a person's balance and cause the person to fail the test and be grounds to have the test results challenged. If a person has nystagmus, they could fail a field sobriety test if the police administered the HGN while their police car lights were flashing. The failure would be due to their health condition and not the result of intoxication.

Improper Instructions and Observation

Police must provide the exact instructions for the performance of the field sobriety tests, or you can challenge the test results. A criminal defense attorney can ask to see the police dashcam footage as evidence and evidence from the officer's body camera to confirm that the officer provided the exact instructions. Since these tests are SFSTs, the instructions must be given exactly as required. This is important since the state may be relying on the test results as their primary evidence since the person suspected of DWI could have refused to provide a breath, saliva, urine, or blood sample. Reasonable doubt could be raised if any part of the test can be successfully challenged in indicating a person had been intoxicated.

Schedule a Consultation With Austin, Texas DWI Attorney Jason S. English

If you have been charged with DWI in Texas and have questions about challenging a field sobriety test, contact Texas DWI defense attorney Jason S. English online or call (512) 454-7548 for more information.

Austin DWI

As someone who prosecuted cases for over 15 years, Jason S. English understands the strategies prosecutors employ in drunk driving criminal cases to coerce the accused into pleading guilty. Before you plead guilty to any crime, understand your rights and explore your options for fighting the criminal charges.

When you're dealing with a DWI, it's not an exaggeration to say that your life depends on retaining an experienced, innovative criminal defense attorney. Attorney Jason English recognizes that your freedom depends on his legal prowess in and outside the courtroom. Contact Jason English today at (512) 454-7548 or online for an initial consultation and help with your DWI arrest.