What Do Officers Look For When Performing A DWI Field Sobriety Test?

FSTs, also known as field sobriety tests, are commonly used by law enforcement officers to determine whether a driver is under the influence of alcohol or drugs. If you’ve been stopped on suspicion of driving while intoxicated, understanding what happens during these tests and how their results may be used against you is crucial.

It is important to talk to a Houston DWI lawyer as soon as possible too, as these tests are often portrayed as straightforward but their accuracy is not always guaranteed. A seasoned attorney can review the circumstances of your case, potentially challenge test results, and fight for your rights. Remember, a failed field sobriety test doesn’t automatically mean a DWI conviction.

What Happens During a Field Sobriety Test?

Standardized exercises designed to measure a person’s coordination, balance, and ability to follow instructions, there are three primary sobriety tests approved by the National Highway Traffic Safety Administration. One of these is the horizontal gaze nystagmus test. For this test, officers observe the driver’s eyes as they follow a moving object, like a pen or flashlight. They look for involuntary jerking of the eyes, which may indicate intoxication.

There is also the walk-and-turn test, when a driver is asked to take a certain number of heel-to-toe steps along a straight line, turn on one foot, and walk back. Officers note balance, ability to follow instructions, and any missteps. Often a one-leg test follows, which is when the driver is instructed to stand on one leg, raise the other approximately six inches off the ground, and count aloud for 30 seconds. Officers observe for swaying, using arms for balance, or putting the foot down.

When conducting an FST, officers aim to assess physical and mental impairment. The process typically involves:

• Initial observations. Officers may note slurred speech, bloodshot eyes, or the odor of alcohol before the test begins.
• Clear instructions are provided for each test. The officer will closely watch to see if the driver understands and follows them.
• Performance assessment. Every movement is scrutinized, from balance and coordination to timing and adherence to instructions. Deviations from expected performance are noted.

For instance, during the horizontal gaze nystagmus test, officers look for eye jerking at specific angles. In the walk-and-turn and one-leg stand tests, they document behaviors such as stepping off the line, inability to balance, or stopping prematurely. These indicators of impairment are often used to justify further investigation or arrest.

Can I Challenge the Results?

Although standardized, FSTs are not foolproof. Factors such as medical conditions, nervousness, uneven surfaces, or even poor footwear can affect performance. The interpretation of results is subjective and may vary by officer. In some situations, an experienced Houston DWI lawyer can challenge FST results by questioning the test conditions, pointing out external influences, or scrutinizing the conduct of the officer who administered the tests.

Have you been subjected to FSTs in Texas? If so, consult with a skilled criminal lawyer. Share the details of your situation with the attorneys at Ayson Law Firm. Contact us today to schedule a confidential consultation.