Field Sobriety Test

In many driving under the influence cases, law enforcement officers will use field sobriety tests to help them determine whether a person is able to drive safely. Effectively, the field sobriety tests allow the officer to build a stronger case against an individual. The field sobriety tests are standardized tests, meaning that the tests are to be given the same way every time according to strict guidelines the officer learns in training.

Many times the officer does not administer the field sobriety tests correctly and these errors are utilized in attacking the state’s case.

There are three standardized field sobriety tests which have been developed by the National Highway Transportation Safety Administration (NHTSA). The three tests are:

1. Horizontal Gaze Nystagmus (HGN)

Horizontal Gaze Nystagmus is an involuntary jerking of the eye that occurs naturally as the eyes move to the side. Frequently, this test is conducted by moving an object (pen or finger) side to side in front of a person's face, and asking them to follow it with their eyes. The head must remain stationary. The officer looks for three “clues” of impairment: 1.) If the eye cannot follow the moving object smoothly. 2.) If jerking is distinct when the eye is at maximum deviation. 3.) If the jerking of the eye starts within 45-degrees of center.

2. Walk and Turn

The Walk and Turn test is administered by having a person take nine steps, heel-to-toe, along a straight line, followed by a turn and then nine steps back in the same direction. The officer looks for eight “clues” of impairment: If the subject 1.) Cannot keep balance while listening to instructions. 2.) Begins before instructions are finished. 3.) Stops while walking to regain balance. 4.) Does not touch heel-to-toe. 5.) Steps off the line. 6.) Uses arms to keep balance. 7.) Makes an improper turn. 8.) Takes an incorrect number of steps.

3. One Leg Stand

The One Leg Stand test is administered by having a person stand with one foot approximately six inches off the ground and count out loud to thirty, or until told to stop. The officer looks for four “clues” of impairment: 1.) Swaying while balancing. 2.) Using arms to balance. 3.) Hopping to maintain balance. 4.) Putting the foot down.