Challenging Field Sobriety Tests

in the San Antonio area

San Antonio and South Texas driving while intoxicated defense lawyers

If you are stopped by an officer suspecting you are driving while intoxicated , the officer will probably ask you to take Standard Field Sobriety Tests (SFST). These tests will likely include a Horizontal Gaze Nystagmus test (also known as HGN), walk and turn, and finger to nose test, to name a few. Remember that any testing done will be used against you in court and you are not required to cooperate with any of this testing. Frequently these tests are used to determine which people to arrest. If you do not cooperate you will most likely be arrested but the police will have less evidence to use against you if your case goes to trial. Sometimes officers will have a small, portable breath test device with them and ask you to take a breath test as part of their screening to determine whether to arrest you or not. Again you can refuse this test.

After arrest and transport to a police or sheriff’s office you will be asked to take a breath test. You may be asked to perform the Standard Field Sobriety Tests again, while the police videotape you, again gathering evidence to use against you. If you are arrested for a DWI it is important to consult with and hire a qualified San Antonio driving while intoxicated lawyer. Certain testing methods like the Standard Field Sobriety Tests are highly inaccurate and can be effectively challenged by San Antonio DWI defense attorneys.

What are Field Sobriety Tests?

Field Sobriety tests are a group of agility movements designed by the National Highway Transportation and Safety Administration (NHTSA) to determine intoxication. Some of the tests officers employ are standardized some are not. These exercises are intended to test balance, divided attention and coordination. These are skills that are usually necessary to operate a car, truck or motorcycle. Field sobriety tests assume that a sober person would be able to pass them. In other words, if you cannot pass the test, you are assumed legally drunk. However, field sobriety tests have only limited accuracy as documented by the National Highway Transportation and Safety Administration (NHTSA). In cases where field sobriety tests were used to convict people 20% – 30% would be wrongly convicted of DWI . Don’t let this happen to you. If you have been arrested for a DWI , contact a San Antonio DWI lawyer immediately.

Common Types of Field Sobriety Tests

Some of the most common types of Field Sobriety tests performed are:

  • Horizontal and Vertical Gaze Nystagmus  – following a pen light with your eyes while the officer checks for unusual eye movement.
  • Walk and Turn   - taking 9 steps heel to toe forward, turning and taking nine back. The person must multitask to perform the test.
  • One Leg Stand   – standing feet together and arms at sides and raising one leg six inches from the ground. The officer will look for using of arms for balance hopping and or swaying.
  • Finger to Nose Test  – With feet together and eyes closed the subject must bring an arm to their nose alternating between arms.
  • Finger Count Test  – Using thumb subject must count fingers forward and backward.
  • Hand Pat Test  – alternate clapping from front to back of hands while counting.

The Horizontal and Vertical Gaze Test, Walk and Turn Test, and the One Leg Stand Test have been shown to be the most accurate of the field sobriety tests by the NHTSA. These three are known as standardized field sobriety tests. Even though these three standardized tests have been shown to be more accurate than others, this is only the case if the tests are performed exactly to specifications. Officers rarely perform the tests to required specifications making the standardized tests easily challenged in a court of law. Most people are not aware that Field Sobriety Tests are not mandatory and may be refused. The officer may not reveal that fact in order to collect more evidence to justify an arrest.

Field Sobriety Tests Not Always Reliable

Field sobriety tests do not always prove intoxication. Fore example, there are many conditions can cause a person to be incapable of putting one foot in front of another including:

  • Unsmooth or uneven surface,
  • Wet or slippery surface
  • Poor lighting conditions (including the police car headlights shining in your face),
  • Dangerous conditions that would make a person nervous or distracted
  • Heels higher than two inches
  • Recent surgery that would cause one to stumble
  • Poor depth perception
  • More than 50 pounds overweight
  • Medical issues that may affect performance
  • The arresting officer might not be certified to administer the test
  • And so many more.

The Horizontal and Vertical Gaze Nystagmus test or pen test is equally as problematic. Police videos do not usually record a person’s eyes during such a test. There is no way to independently verify whether or not a person’s eyes jerked to the severity that the officer claims. Officers may or may not be certified to test for Nystagmus, but they are usually not medically trained. With no independent testing available to confirm the officer’s assertion that your eyes were extremely jerky, how credible is that test?

Officers must have a just reason to make an arrest and if it can be proven that the officer made an illegal arrest, then all evidence gained after that point cannot be used against you.

ust because field sobriety tests are “standardized” it does not mean that they are dependable or scientific. These tests are subject to many flaws and therefore they are often successfully challenged or even suppressed from the evidence against you. Hire a qualified San Antonio DWI defense attorney. An experienced San Antonio DWI lawyer will be able to examine the specific facts of your case and determine the best defense for you.

What you can do

Have you or a loved one been arrested and charged with driving while intoxicated in or around the San Antonio area. Find an experienced DWI defense lawyer who is able to aggressively fight for you. It is important to hire a lawyer experienced defending DWI cases. A DWI conviction can lead to license suspension, a criminal record, probation, hefty fines, increased insurance costs, and jail time. If you are facing a driving while intoxicated in or around San Antonio call our office for a free consultation.