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Overview of field tests and common challenges

An officer can pull a suspected drunk driver over and conduct several field tests. There are several standard tests that an officer may use to check for signs of DUI, but a driver in Marietta, Georgia, can challenge the results.

Standard field sobriety tests

The horizontal gaze checks for eye blinking, or nystagmus, by having the driver follow an object with their eyes. The officer holds a finger, pen or light 12 to 15 inches away to check for involuntary blinking at 45 degrees. This can help the officer check for signs of DUI.

During the one-leg stand test, the driver stands with one leg 6 inches above the ground for 30 seconds. The driver walks in a straight line during the walk-and-turn test, turns on one leg and repeats in the other direction. These tests check balance, coordination and the ability to follow directions, and the officer looks for signs of intoxication.

Challenging field sobriety test results

The accuracy of field sobriety tests is questioned since they can sometimes be difficult for sober people to pass. If the officer leaves out important instructions, considerations or preliminary questions, it may cause the driver to fail.

For example, the officer should ask the driver if they have contact lenses or an eye condition that could impact results. They should ask them to take off high heels that can cause balance issues during the walk-and-turn test.

Other medical conditions can impact results and throw off balance, such as brain injuries, skeletal disorders and ear infections. The anxiety alone from getting stopped by officers can make the driver nervous and fail the test even while sober. If an officer uses a non-standard test, such as touching fingers to the nose, the judge may consider the test unreliable.

The prosecution must prove that the driver was drunk beyond a reasonable doubt to convict. Some defenses may convince the judge and jury that the driver was not actually drunk when they got stopped. This might be enough doubt to result in reduced charges or an acquittal.