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If the officer believes you have been drinking, you will be asked to step out of the vehicle. Once you have exited the vehicle the officer may ask you more questions or ask you to perform certain tasks. You have the option to refuse to perform these tasks.


NHTSA develop standardized tests for police officers across the country to use when evaluating drivers who are suspected of Driving While Intoxicated. These standardized methods are now known as Standardized Field Sobriety Tests (SFST).


The SFSTs consist of three tests that officers administer and evaluate in a standardized manner on the roadside. The officer’s evaluations of the driver’s performance during these tests help the officer decide whether to arrest the driver for DWI. The three tests that make up the SFST are:


  1. Horizontal Gaze Nystagmus (HGN)

  2. Walk and Turn

  3. One-Leg Stand


HGN is an involuntary jerking of the eyes that occurs as the eyes move from side-to-side. When a person is intoxicated, the jerking is exaggerated and may occur at lesser angles depending on the degree of intoxication. The Walk and Turn and One-Leg Stand Tests are self-explanatory. However, officers generally ask you to perform simple, physical tasks while you walk and turn or stand on one leg. The officer’s evaluation of your ability to perform these tasks assists the officer in deciding whether to arrest you for DWI.


An experienced DWI lawyer knows that there are several factors that could affect your performance during the SFST. Some common factors that could cause you to appear intoxicated are anxiety, mental or physical disability, and bad weather conditions. An experienced DWI lawyer may also notice that the officer that conducted the SFST was poorly trained. If you have been arrested for DWI in Texas, contact the Loker Law Firm today to discuss your case with an experienced Texas DWI lawyer.

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