Gaynell Williams Law DWI Blog – What is a Field Sobriety Test?

Field sobriety tests are tests conducted by the officer at the scene after the motorist is stopped by the police officer for a traffic violation or for suspicion of driving while intoxication (DWI/DUI). These tests provide evidence to the officer as to whether the motorist is intoxicated. There are certain non -standard field sobriety tests (FSTs) that a law enforcement officer may use while a motorist is still seated in his car to determine if the motorist was driving while intoxicated (DWI). These tests include: (1) the ABC test; (2) the Finger to Nose Test; (3) the Backwards Count test;  and (4) the Finger Count Test. Further, there are three tests that have been approved by the National Highway Traffic Safety Administration (NHTSA) that can be used by a law enforcement officer to determine if a motorist is intoxicated after the motorist exits the vehicle. These tests are known as standardized field sobriety tests  (SFSTs) and are approved by many courts in determining intoxication. Those tests are: (1) the horizontal gaze nystagmus test (HGN); (2) the walk-and-turn test (WAT); and the one leg stand test (OLS). A thorough understanding of these tests will help an experienced/aggressive DWI/DUI lawyer defend those clients who are charged with DWI or DUI.

1. ABC Test

The ABC test is administered by having the motorist recite a section of the alphabet beginning on a letter other than “A” and ending on a letter other than “Z”.   This test divides the motorist’s attention between concentrating on actually saying the letters correctly and recalling on which letter to begin and which letter to end.   Divided attention tests are simple and indicative of possible impairment because it is difficult for an impaired driver to handle multiple tasks at once.

2. Finger to Nose Test

The Finger to Nose test begins with the motorist standing with feet together, head tilted back, eyes closed, and arms out to the sides (perpendicular to the body).   The officer then instructs the motorist to touch the tip of his nose with his index finger, only bending his arm at the elbow and keeping the upper arm out to the side.   The motorist should touch his nose with the hand that the officer calls out loud.

3. Backwards Count Test

The Backwards Count test requires the motorist to count out loud 15 or more numbers in reverse order.   The officer should never request that the starting and stopping points are numbers which end in 0 or 5, as these are very easy to recall.   Instead the numbers should be more random, such as instructing the motorist to count backwards from 58 to 43.  This test also divides the motorist’s attention between concentrating on correctly counting backwards while trying to remember where to begin and end.

4. Finger Count Test

The Finger Count test consists of the motorist consecutively touching the tip of the thumb to the tip of each finger, on the same hand, beginning with the pointer finger while simultaneously counting one, two, three, four; then reverse the direction, beginning on the pinky finger, counting four, three, two, one.   To clarify, the fingers and numbers should coordinate as pointer finger-one, middle finger-two, ring finger-three and pinky finger-four.

5. Horizontal Gaze Nystagmus

Prior to administration of the test, the officer must ensure that the motorist’s eyes can be seen clearly, such as in a well-lit area or by illuminating the motorist’s face with a flashlight.   Also, the officer must not have the subject face the flashing lights of the police cruiser or the headlights of passing cars as this has the potential to induce other types of nystagmus.   The subject can be either sitting or standing for the administration of the HGN test.   Although the removal of contact lenses is NOT required, officers are taught to note if the subject is wearing contact lenses and which type, hard or soft.   Hard contact lenses could possibly pop out when the eye is moved as far to the side as possible.   Removal of eyeglasses makes it easier for an officer to observe eye movement.   It should be noted that the wearing of either eyeglasses or contact lenses does not affect the HGN test or results in any way.

Next, the officer should inform the motorist, “I am now going to check your eyes.”   This step is not the HGN test but used to assess whether the subject has a possible medical impairment causing the nystagmus, which could invalidate the HGN.   The eyes are checked for equal pupil size, resting nystagmus (jerking of the eyes as they look straight ahead), and equal tracking (can the eyes follow an object together?).   The procedure to check for a medical impairment is for the officer to position a stimulus, such as a pen or finger approximately 12-15 inches from the motorist’s nose and slightly above eye level.   The stimulus is positioned in this location to enable the motorist’s eyes to open further and makes it easier to observe the eye’s movement.

With the eyes in this optimal position, the officer can then assess both pupil size and resting nystagmus.  If the pupils are not equal in size, this could indicate a head injury.   If resting nystagmus is observed, this could indicate a pathological disorder, such as brain damage, or a high dose of a Dissociative Anesthetic Drug, such as PCP, and the officer should proceed with extreme caution.   To observe equal tracking, the officer first instructs the motorist to follow the stimulus with his eyes only and to keep his head completely still.   If the motorist is having difficulty keeping his head still during the test, the officer should instruct the motorist to hold his own head still by pressing the palms of his hands to his cheeks or to hold his own chin.

The officer should then confirm that the motorist understands the instructions.   Now the officer checks for equal tracking by moving the object smoothly but quickly across the subject’s entire field of vision to see whether the eyes are following the object simultaneously.   If the eyes do not track together, this could indicate a possible medical impairment or injury.   If the motorist exhibits any of these indicators, the officer needs to be cognizant of a possible medical disorder or injury which could require foregoing the HGN test and seeking medical assistance.

Once the officer rules out any possible medical impairments, he then performs the HGN test looking for six clues, three in each eye.   The 3 clues which indicate impairment are “lack of smooth pursuit”, “distinct nystagmus at maximum deviation”, and “onset of nystagmus prior to 45 degrees”.   The officer checks the left eye for the first clue then checks the right eye for the same clue before moving onto the next clue.

6. Lack of Smooth Pursuit

Again, beginning with the stimulus situated approximately 12-15 inches from the motorist’s nose and slightly above eye level, the officer moves the stimulus smoothly to his right, at a speed that requires approximately two seconds to bring the motorist’s eye towards the motorist’s left ear as far as possible.   While moving the stimulus, the officer is looking at the motorist’s left eye to ensure that it is able to pursue the stimulus smoothly.   To check the right eye, the officer now moves the stimulus to the left, back across the motorist’s face at the same rate of speed continuing to the right ear.   The officer is now checking the right eye for smooth pursuit.  If there is a “lack of smooth pursuit”, the officer notes for which eye the clue was observed.   This concludes two of the six clues.

7. Distinct Nystagmus at Maximum Deviation

After both eyes have been checked for “lack of smooth pursuit”, the officer checks for the next clue, “distinct nystagmus at maximum deviation.”  The officer once again begins with the stimulus centered on the motorist’s face.  To check the left eye, the officer moves the stimulus towards the motorist’s left ear until the eye has gone as far to the side as possible.   This is very similar to the procedure used for “lack of smooth pursuit”, except in this clue, the eye is held at maximum deviation for a minimum of four seconds and the officer is looking for a “distinct AND sustained” nystagmus.   The officer then moves the stimulus all the way across the motorist’s face to check the right eye, again holding the stimulus at maximum deviation for four seconds.   If observable, the officer notes a distinct and sustained nystagmus at maximum deviation in each eye.   This concludes four of the six clues for HGN.

8. Onset of Nystagmus Prior to 45 Degrees

The third clue that the officer should attempt to observe is “onset of nystagmus prior to 45 degrees.”  This third test also begins with the stimulus centered at the motorist’s nose.  The officer then moves the stimulus towards the motorist’s left shoulder at a speed that would take approximately four seconds for the stimulus to reach the motorist’s shoulder.   The movement of the stimulus is substantially slower in this clue.  The officer will be intently watching the left eye for any sign of jerking prior to the stimulus reaching 45 degrees from the center of the motorist’s face.   If jerking is noticed, the officer will stop moving the stimulus and verify that the jerking continues at that point.   This angle is usually determined by the officer checking to see that some white of the eye is still visible on the side of the eye that is closest to the ear.   Another way officers determine 45 degrees from the center of the motorist’s face is at the point where the stimulus is in front of the inside tip of the subject’s shoulder.   This is the last two of the six clues for HGN.

The officer then checks for vertical nystagmus by starting the stimulus again at the motorist’s nose and raising the stimulus until the eyes are at maximum elevation and held at that point for approximately four seconds.   This is similar to “distinct nystagmus at maximum deviation” except the stimulus is moved vertically instead of horizontally.

9. Walk-and-Turn

The Walk-and-Turn is the second SFST and is also referred to as a divided attention test.   A divided attention test requires the subject to concentrate on two or more things at once.   A divided attention test is a good SFST because driving is a divided attention task.  Drivers must simultaneously control steering, accelerate and brake, react to obstacles in the road, and perform a multitude of other tasks.   It is very difficult for someone to divide his attention when impaired.   The key to an effective divided attention field sobriety test is simplicity.   The Walk-and-Turn is a test that is reasonably simple for an average person to perform while sober and requires the subject to do two things at once, making it simple while dividing the subject’s attention.

10. Administration of Walk-and-Turn

The Walk-and-Turn consists of two stages: 1) The Instructions stage; and 2) The Walking stage.   The Instructions stage begins with the officer instructing the motorist to assume a heel-to-toe stance on a real or designated imaginary line.   In an effort to standardize all testing procedures and make the instructions absolutely clear, the officer must demonstrate the stance while instructing the motorist to place his left foot on the line.   Next, the officer instructs the motorist to place his right foot on the line ahead of the left foot, with the heel of his right foot against the toe of his left foot.   Again the officer needs to demonstrate.  The motorist is then instructed to place his arms down at his sides and this task is again demonstrated by the officer.   The officer now instructs the motorist to remain in this position until the instructions are completed and the officer emphasizes that the motorist may not start to walk until told to do so.   The officer then confirms that the motorist clearly understands the instructions up until this point and also verifies that the motorist indicates his understanding of the instructions.  This position is the initial position which is to be maintained throughout the testing instructions.   After assuming the correct position, the officer will continue with the actual testing instructions.  This divides the motorist’s attention between balancing and listening to and remembering the remaining instructions.

The officer then continues with the instructions and demonstrations for the Walking stage.  The Walking stage divides the motorist’s attention between walking heel-to-toe, counting out loud and recalling the number of steps and the manner in which to make the turn.   When instructed to start walking, the motorist is to take nine heel-to-toe steps, turn and take nine heel-to-toe steps back.   The officer should demonstrate by taking three heel-to-toe steps.   When it is time for the motorist to turn around, he is instructed to “keep his front foot on the line and make a series of small steps with the other foot” in order to make the turn.   The officer demonstrates how the turn is to be completed.  The motorist is then instructed to keep his arms at his sides, watch his feet at all times and to count his steps out loud, while he is walking.   The motorist is instructed that once he starts walking, he is not to stop until he has completed the test.   The officer then asks the motorist if he understands the instructions and verifies that the motorist clearly understands.   Lastly, the officer instructs the motorist to begin taking his heel-to-toe steps and to count his first step as “one.”

11. One-Leg Stand Test

The third, validated and standardized, field sobriety test is the One-Leg Stand test.  The One-Leg Stand is similar to the Walk-and-Turn because it is also a divided attention test which consists of two stages, the Instructions Stage, and the Balance and Counting Stage.

12. Administration of One-Leg Stand Test

Consistent with divided attention tests, for the Instructions Stage of the One-Leg Stand test, the suspect is placed into a standardized position, feet together and arms at sides, while the Instructions are explained to him.   The Instructions Stage divides the suspect’s attention between balancing, and listening to and remembering instructions.   The officer must demonstrate how he wants the suspect to stand and tells the suspect not to start the test until instructed to do so.   The officer then asks the suspect if he understands the instructions so far and must confirm that the suspect does in fact understand.

Now the officer can begin the Balancing and Counting Stage.  This stage divides the suspect’s attention between large muscle control, by balancing on one leg and small muscle control, in the form of counting out loud.   With the suspect still in the initial stance of legs together, the officer now tells the suspect to start only when instructed to do so, by raising one foot approximately six inches off of the ground and keeping that raised foot parallel to the ground.   The officer must demonstrate in order to clarify.   The suspect is told to keep both legs straight and arms at his sides.   The officer now instructs the suspect to keep looking at his raised foot while counting, “one thousand and one, one thousand and two, one thousand and three”, in that manner until told to stop counting.   The officer must demonstrate how the counting is to be conducted.   Again, the officer asks the suspect if he understands the instructions and the officer must verify that the suspect understands.

Next, the suspect is instructed to begin the test.   The officer should allow the test to continue until the suspect reaches the count of thirty.   Research from the 1983 NHTSA study found that far fewer impaired subjects could stand on one leg for thirty seconds as opposed to twenty-five seconds which is why the standardization for timing is thirty seconds.   The researchers concluded that standing on one leg for twenty-five seconds was far too easy of a test.  If at any point the suspect touches the ground with the raised foot, the officer should instruct the suspect to raise his foot back up and continue counting at the number he was on when his foot touched the ground.  This test is not timed for thirty seconds but rather the suspect must count to thirty.  It may take a very impaired driver two minutes to count to thirty because of the mistakes he is making.

If you are in need of a DWI/DUI, criminal defense, expungement, or personal injury lawyer, please contact Gaynell Williams today at 504-302-2462 for an appointment so that an aggressive lawyer who will be committed to your case can assist you today. Evenings and weekend sessions are available by appointment. We will work around your schedule.

Sources: Nat’l Highway Traffic Safety Admin., Dep’t of Transp., DWI Detection and Standardized Field Sobriety Testing: Student Manual (Feb. ed. 2006); Marcelline Burns & Herbert Moskowitz, S. Cal. Research Inst., Psychophysical Tests for DWI Arrest 3, DOT-HS-5-01242 (1977); and  Nat’l Highway Traffic Safety Admin., Dep’t of Transp., DWI Detection and Standardized Field Sobriety Testing: Adm’r Guide B-3 (2002).

By |2018-08-02T22:08:56+00:00October 15th, 2015|Uncategorized|Comments Off on Gaynell Williams Law DWI Blog – What is a Field Sobriety Test?

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