My daughter has been arrested for drunk driving in Houston, Texas. She was asked to perform field sobriety tests and she failed them. I was told that these tests do not accurately determine driver impairment. Can she use this as a defense?

Madison

Houston, TX

Yes, it’s true, field sobriety tests (FST’s) do not accurately measure the driver impairment for probable cause to support an arrest for DUI. So your daughter can use that as a defense in her DUI case in Houston, Texas. Many researchers observed that FST’s determine balance, reaction time and steadiness but concluded that a connection between these factors and driving ability was not apparent. That’s because neither a simple movement time nor steady stance is essential to the safe operation of a motor vehicle. The researchers conceded that FST’s may show the presence of alcohol but did not necessarily measure driving ability.

In general, police officers do not give the FST’s uniformly and there is no scientific basis for assuming these tests are valid. Many of these officers either improperly instruct the suspect driver on how to perform the tests or administer the wrong tests. A DUI defense lawyer can obtain a pre-trial suppression ruling to exclude the FSTs and their alleged indication of impairment due to lack of improper instructions and scientific foundation.