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Blogs from July, 2013


If you are pulled over by law enforcement who suspects intoxication, they may conduct field sobriety tests. There are three common tests that will be performed. The three tests make up the Standardized Field Sobriety Test (SFST) and they include:

  1. Horizontal Gaze Nystagmus (HGN)
  2. Walk- and- Turn (WAT)
  3. One- Leg Stand (OLS)

These three standard tests came about in the 1970's by the National Highway Traffic Safety Administration (NHTSA) in order to help determine if a driver is intoxicated. Unfortunately, the accuracy of these tests vary depending on the arresting officer and whether or not they conduct the tests correctly. Team up with a San Antonio criminal defense lawyer if you have been arrested after failing field sobriety tests.

Types of Field Sobriety Tests

The first test, Horizontal Gaze Nystagmus is to test the jerking of the eyes. The word Nystagmus means involuntary jerking of the eye and the test looks into the jerking as the driver gazes to the side. The test is given because of a theory that nystagmus will become noticeable when the driver is under the influence. When giving the test, law enforcement will tell the driver to follow the motion of a stimulus with only their eyes. They may use a pen, light, pencil, finger or something along those lines. While the eyes move to the side, they will see if the eyes show signs that are thought to mean impairment.

The second test, Walk and Turn is to test balance and attentiveness. The driver will be instructed to walk heel- to- toe and to not begin until the instructions are complete. While walking, they must take nine steps and turn in a certain way and then take another nine steps back. They have to count out loud and watch their feet while doing so. The officer will observe and look for clues such as the driver's balance, their obedience to the instructions, and the accuracy of their performance (maintaining heel-to-toe and staying on the line).

The third test, One-Leg Stand involves the driver standing with their feet together and being instructed to keep their arms at their side while raising their leg. The leg must stay straight and pointed out about six inches from the ground. The driver is directed to look at their foot while counting "one thousand and one, one thousand and two," and so on. While the driver does so, the officer will keep a look out for swaying, hopping, using arms for balance or placing the foot on the ground.

Field Sobriety Test Results Can Be Challenged!

Fortunately, there are many ways to fight the results of a field sobriety test. The arresting officer must conduct the tests in a flat, dry and stable area and in the standard manner. If they fail to do so in any way, the results may be invalid. The San Antonio DWI attorneys at The Law Office of John J. Fox investigate into our client's cases to make sure we know all of the facts involved. Contact our firm if you need representation in your DWI case!