How Field Sobriety Tests Can Affect the Outcome of your DUI Case

When a police officer suspects a driver of being under the influence of drugs or alcohol, they may conduct field sobriety tests (FSTs). There are a number of non-standardized tests that an officer may administer, but there are three main tests that most officers conduct in the course of a DUI traffic stop.

Horizontal Gaze Nystagmus Test: A police officer will hold up an object, usually a pen, or a finger and ask the driver to follow the object with their eyes back and forth. By carefully watching the driver’s eyes, the police officer will attempt to discover a bouncing of the eye. This bouncing is called horizontal gaze nystagmus. In some DUI cases, observing unsmooth eye movements or early onset may mean the driver has been drinking. This test is subject to the training and ability of the officer giving the test. Technically, only an ophthalmologist can truly administer this test and there are many other naturally occurring conditions besides alcohol that may cause nystagmus.

Walk and Turn: In this test, the driver will be asked to take nine steps, pivot and then walk back. While walking heel-to-toe, the driver will have to count the steps out loud. Someone who is significantly inebriated will have difficultly balancing while walking and may make mistakes while counting. But even if the driver just needs to hold out their arms to balance or they count wrong, the officer may deem it a failed test and charge them with a DUI case.

One Leg Stand: The driver will be asked to lift one foot about 6 inches off the ground while counting to 30. The police officer will be watching to see if the driver needs his arms to balance. An officer can make an arrest if they find the driver’s performance of this test inadequate.

Many people may assume that you need to take a blood alcohol test to prove you have been driving intoxicated, but the truth is that you can be charged with DUI for failing any of these field sobriety tests. These tests must be conducted in a certain manner in order to be valid. We are Southern California DUI defense attorney who can review your DUI case to determine if the tests were conducted properly. And we will determine whether there were other factors, such as an illness, fatigue or a prior injury that may have caused you to fail a field sobriety test. If you have been charged with drunk driving, please contact the DUI lawyers of Sitkoff & Hanrahan at 866-430-8383 for a free consultation.