Brick wall with the letters DUI lit up


Venessa Bornost
April 29, 2022

There are a variety of clues an officer will gather when conducting a DUI investigation. The initial observation begins with the driving pattern of the individual. If the officer has probable cause to believe the driver has committed a traffic infraction the next set of observations is how the driver handles the vehicle upon stopping and then the observations of the driver once the officer makes contact with the driver.

If the officer suspects that the driver may be under the influence of an alcoholic beverage the officer may ask the driver to consent to Field Sobriety Exercises. (SFSEs).

The FSEs were developed and are administered by the National Highway Traffic Safety Administration and are standardized throughout the United States. The exercises include the horizontal gaze nystagmus, walk and turn, and the one leg stand.

In Horizontal Gaze Nystagmus (HGN) the officer will check the driver’s eyes holding a pen light stimulus 12-15 inches from the driver’s face. The officer instructs the driver to follow the tip of the pen with the eyes and eyes only. Nystagmus is an involuntary jerking of the eye.

During HGN the officer will check for lack of smooth pursuit which means the eyes do not smoothly pursue the moving stimulus but move in a jerky manner, nystagmus at maximum deviation which a distinct jerking occurs when the eyes are deviated as far as possible during the horizontal plane, and onset of the jerking movement prior to 45 degrees which nystagmus occurs and remains at an angle of gaze less than 45 degrees. The examination for three signs in each eye will yield a possible score of six. The minimal decision clue is 4.

The next exercise is the Walk and Turn Exercise. These consist of standardized instructions to walk nine heel-to-toe steps along a line, turning, and walking the line nine heel-to-toe steps back down the line.

The officer will note on the evaluation the following: loss of balance during instruction, starts before instructions are finished, stops while walking, doesn’t touch heel-to-toe, steps off the line, uses arms for balance, loses balance while turning or makes incorrect turn, incorrect number of steps, can’t perform test. There are a total of 9 clues and the minimum decision clues are 2.

In the One Leg Stand exercise the instructions are to stand with your heels together, arms down at the sides at all times. The person is to raise one leg, either leg, approximately six inches off the ground, keeping the raised foot parallel to the ground. Both legs must be kept straight, arms at the side. While holding the position the person must count out loud until told to stop while keeping arms at the side at all times and keep watching the raised foot.

The officer will note if the person sways while balancing, uses arms for balance, hopping, puts foot down, can’t perform a test. There are a total of 5 clues and the minimum decision clues are 2.

These are the most common field sobriety tests which are administered by law enforcement however there are other alternate tests as well which may be used due to the persons’ age or health condition.

Alternative Tests:

Finger-To-Nose Test: the officer will ask the driver to stand with their feet together, arms down at the side, and index finger pointed. Then with you eyes closed and head tiled back, using the hand specified by the officer, you will bring the hand directed upward then touch the tip of your index finger to the tip of your nose, and then return your arm to the original position.

Here in the finger-to-nose test the officer will look for the following decisional clues: the driver does not keep eyes closed, does not return arm to side, index does not touch nose, uses wrong hand, and can’t perform test.

Rhomburg Test: Here the officer will instruct the driver to stand with heels together, with hands at your side, close your eyes, tilt your head back and recite the alphabet slowly in a loud, clear voice, do not rhyme it or sing it.

The decisional clues the officer will be looking for are: does not keep eyes closed, sways, uses arms for balance, alphabet recited incorrectly, can’t perform test.

There may be many factors which may effect a driver’s ability to perform any of these exercises, issues with the way the officer administered the tests, or conflicts between the observations of the officer.

If you have been arrested for DUI and would like to discuss your case further feel free to contact my office at (727) 977-5408 and ask for Venessa.