What should you know about field sobriety tests?

If police pull you over under suspicion of drunk driving, they will likely ask you to perform standardized field sobriety tests. You have probably seen dash cam footage of such tests on the evening news, but there are three things you should know about these tests.

1. There are three types of tests

The National Highway Traffic Safety Administration (NHTSA) supports three tests to help determine whether or not someone is under the influence of alcohol. They include:

  • The horizontal gaze nystagmus, in which someone follows an object with only their eyes (However this test is inadmissible in court in Tennessee but is still used by officers to create probable cause to arrest).
  • The one-leg stand test, in which someone attempts to balance on one leg for roughly thirty seconds
  • The walk-and-turn test, in which someone walks in a straight line, then turns to walk back

Alcohol affects your gaze, balance, and ability to comprehend instructions. So, for example, if drivers cannot walk in a straight line or balance well, it could indicate they are impaired. However, these tests are not completely reliable. Individually, they are only about 60% to 70% accurate.

Important: It is critical to inform police of any reason why you might fail a test unrelated to impairment. The police should ask you for any such reason, but even if they do not you should make sure they note any disability or injury, your age, or any other condition that might affect your ability to participate in these tests.

2. Police use the tests to find probable cause

What is the point of field sobriety tests? They serve as a technique for police to obtain probable cause to arrest you for a DUI.

The police may suspect drunk driving when they pull you over, or when they come up to the window during the actual traffic stop. However, that is not enough to arrest you. What the police observe during these tests could give them reason and cause to believe you are impaired, and, in turn, arrest you.

3. But you can refuse these tests

There is no specific penalty for refusing a field sobriety test. It is not a violation of the implied consent law, like refusing a breath or chemical test after the arrest. However, the police may still arrest you if they perceive impairment, even without conducting the field sobriety tests.

There is no way to predict when a traffic stop may occur, but you can take steps to understand what to expect and protect your rights in this situation.

Whether you “pass” field sobriety tests if you decide to attempt them is completely subjective and within the interpretation of the officer. Many people could not perform field sobriety tests 100% sober. Therefore, if you did not refuse to take field sobriety tests and are arrested for DUI, it is important to hire an experienced criminal defense attorney that has the knowledge of how to challenge those tests.

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