Field Sobriety Testing

Field Sobriety testing is the most common tool law enforcement officers use to establish probable cause to place Georgia citizens under arrest for DUI.  While field sobriety testing has evolved over the years, the National Highway and Traffic Safety Administration (NHTSA) has standardized three tests to be used in every DUI alcohol investigation.  The battery of three tests include the horizontal gaze nystagmus test, the walk and turn evaluation, and the one leg stand evaluation.  Police Officers throughout our Georgia have been trained on how to perform and interpret NHTSA’s field sobriety tests.  However, a close examination of field sobriety testing shows that these tests establish a low threshold in determining whether a driver is under the influence of alcohol.  Let’s go through each of the three tests in turn and discuss how they work.

Horizontal Gaze Nystagmus (HGN)

The horizontal gaze nystagmus test is commonly referred to as the “eye test.”  I meet clients every day who tell me that they feel like they passed the “eye test” because they were able to follow the officer’s pen or finger (“stimulus”) during the examination.   Often, the Officers don’t explain that they aren’t looking to see if the driver is tracking properly.  Instead, the Officer is looking for a medical condition called horizontal gaze nystagmus.   Horizontal meaning left to right, and nystagmus meaning the involuntary jerking of the eye.  The Officer is trained to position his pen or finger slightly above eye level and approximately 12-15 inches away from the driver’s nose.  The Officer then is trained to do a series of passes moving the stimulus right to left and at variable speeds.   Ultimately, the Officer is looking for 3 different “clues” of impairment (6 total for both eyes) to look for in each eye.  While the Officer is going side to side, he is looking to see if the eye jerks at different portions of the test.  NHTSA has trained Officers that if a driver displays four of the six possible clues, they are deemed to be impaired by alcohol.

Anyone who has ever been to the eye doctor knows that the first thing the doctor does is turn off the lights to eliminate any distractions from the patients field of vision.   The idea is the doctor will be able to focus on the subtle differences in someone’s eyes and be able make sure the symptoms being observed are not being caused by an outside distraction.  The horizontal gaze nystagmus test was originally designed for doctors, not police officers.   Neurologists and Optometrists use this test to find different types of medical conditions, not necessarily alcoholic impairment.   However, NHTSA trains officers to use this test on the side of the road, which is not a controlled environment.  In addition, nystagmus is often very subtle and it can be mistakenly observed if the eye being distracted by outside movements.

For a lawyer, examining the horizontal gaze nystagmus test means that we must examine the dash board video (if there is one) to determine if the Officer did the requisite number of passes.  Unfortunately, there is no way for us to retroactively look back to see if a driver’s eyes were jerking or shaking because the camera is often positioned 15-20 feet away from where the test is be conducted.  However, our lawyers can use the timing and execution of the Officer’s passes to determine whether that aspect of the test was conducted properly.   In addition, the Officer’s knowledge or lack there of, the science behind the horizontal gaze nystagmus test can shed light to the jury on the Officer’s credibility.   Ultimately, the horizontal gaze nystagmus test is a difficult test for Officer’s to accurately administer, especially on the side of the road.   Unfortunately, Officers across Georgia place a heavy emphasis on the horizontal gaze nystagmus examination, an examination that was not originally designed for field sobriety testing.

WALK AND TURN EVALUATION

The next two tests, the walk and turn evaluation and the one leg stand, are considered agility tests that are supposed to demonstrate a driver’s coordination and balance.  NHTSA refers to these tests as “divided attention” tests.   Driving is a divided attention task, which means our bodies go through several different tasks, simultaneously, while driving.  For example, we may have to check our mirrors while applying the break.  Or we may have to speed up while turning the wheel.   We certainly take these tasks for granted because our minds perform these tasks subconsciously.  But, our minds are constantly moving while we’re driving.

To determine if someone is impaired, or unable to multi-task while driving, NHTSA designed agility tests that would simulate the body functions needed to be a safe driver.   So, Officers are trained to first conduct the walk and turn evaluation.   The evaluation is broken up into two phases the instructional phase and the walking phase.   The instructional phase consists of the Officer placing the driver into the “starting position” and watching to see if the driver stays in that position while the Officer explains the walking phase.  The driver is not aware that the Officer is actually looking for two things, whether the driver starts too soon or if they break the starting position.  In fact, the driver is completely unaware that the examination has even begun.   Interestingly, the Officer only needs two “clues” of impairment on this examination to place a driver under arrest for DUI.   So, if the driver starts too soon or breaks the heel to toe position, then the driver has already failed the examination.  Even before starting to walk the line.

The driver then is instructed to walk nine steps out and make the required turn (almost everyone messes up the turn) and walk nine steps back.   During the walking phase the Officer is looking for “clues” of impairment.   For example, if the driver were to miss touching his heel to toe by an inch, then the driver has shown a “clue” of impairment.   The examples could go on for days, but what’s important to note is there are 76 opportunities to show a clue, if the driver shows 2, then NHTSA indicates the driver is impaired.  What this means is that a driver could complete 97% of the evaluation perfectly.  But, according to NHTSA, the driver would still be deemed an impaired driver.  Doesn’t seem fair, does it?

ONE LEG STAND EVALUTION

The one leg stand evaluation is the final agility test and it’s almost as ridiculous as it sounds.   The Officer is trained to have the driver hold one leg in the air, approximately six-inches off of the ground, and have the driver count out loud.    The driver is not informed of how long to hold their leg or the purpose of the test.  Instead, they are instructed to just count.    The Officer then will watch for four “clues of impairment.”   If the driver hops, that’s a clue.  If the driver puts their foot down, that’s a clue.  If the driver sways in any direction while trying to balance, that’s a clue.  Finally, if the driver raises their arms for balance, that’s a clue.   The Officer only needs two clues to establish, under the NHTSA standards, that someone is impaired. 

I often tell juries: “thank goodness there is a video.”    Because the video will always tell the truth.  Jurors are smart.  They understand when someone looks like they aren’t safe to drive or when they are merely being shown evidence of examinations that are designed to fail.   The video will often show that.   And if there isn’t a video in your case, then our lawyers are trained to show the jury how the NHTSA field sobriety tests really work and whether or not they live up to what they are designed to do.   If you’ve been arrested for DUI, don’t just go in and plead guilty.  Our lawyers are trained on how to evaluate DUI cases and determine whether or not the Officer’s field sobriety testing is enough to put a permanent conviction on a Georgia citizen’s criminal history.   For a free consultation call 404-581-0999.