Field Sobriety Tests Defined
In South Carolina, if you are pulled over on suspicion of DUI, the officer may ask you to perform field sobriety tests. The National Highway Traffic Safety Administration (NHTSA) has sanctioned three field sobriety tests to be used to determine if a person is driving under the influence: the horizontal gaze nystagmus (HGN), the one-leg stand and the walk-and-turn tests. Each of these are designed to help law enforcement gauge the relative sobriety or intoxication of a driver.
Do I Have the Right to Refuse the Field Sobriety Tests?
Yes, it is your right to refuse to perform these roadside test and refusing to perform the tests does not carry the same consequences as refusing to submit to a breath test. Meaning, the refusal of these tests can not be used against you during the trial of your case.
Field Sobriety Tests Explained
If you are pulled over on suspicion of driving under the influence, field sobriety tests may be conducted by the officer. These are not pass/fail tests, but rather clues that assist the officer in determining whether or not you are too impaired to safely operate a motor vehicle. The field sobriety tests are explained in further detail below.
What is the Horizontal Gaze Nystagmus (HGN) test?
“Horizontal Gaze Nystagmus” or HGN is an involuntary jerking of the eye as it gazes towards the side. This jerking becomes noticeable when a person is impaired by drugs or alcohol. As a person’s blood alcohol concentration rises, the eyes will begin to jerk sooner as they move from side to side. In administering the HGN test, an officer asks the subject to follow a stimulus (usually the officer’s finger or a pen) as the officer moves the stimulus from side to side within her field of vision. The officer will instruct the subject not to move her head while following the stimulus with her eyes. During this test, the officer looks for six distinct “clues” (3 clues per eyes) by performing these tests to determine whether or not the subject is impaired. The National Highway Traffic Safety Administration (NHTSA) states that if four or more clues are evident, it is likely that the subject’s blood alcohol concentration is above a .10.
What is the Walk and Turn test?
The Walk and Turn test has two stages: the instructional stage and the walking stage. During the instructional stage, the subject is asked to stand with her feet in a heel-to-toe position and keep her arms at her sides while listening to the officer’s instructions. The officer asks the subject to do this so that her attention will be divided between the balancing task (maintaining the position described above) and the information processing task (listening to and remembering the officer’s instructions). While the subject is standing heel-to-toe, with her left foot on the line and her right foot on the line in front of her left foot with the heel of her right foot against the toe of her left foot, and with her arms at her sides, the officer will instruct her to not begin the test until she is told to do so. He will ask her if she understands. The officer will instruct the subject to take 9 heel-to-toe steps on an imaginary line. The officer will demonstrate proper steps. The officer instructs the subject to turn in a very specific way—by keeping her front foot on the line, and turning by taking a series of small steps with the other foot. The officer will demonstrate this turn. The officer instructs the subject to begin, and reminds her to keep her hands at her sides, count her steps out loud, look at her feet while counting, not raise her arms up from her sides, and not stop once she begins. The officer will then instruct the subject to begin and count her first step from the heel-to-toe position as “one.” The subject’s performance is the walking stage.
Like in the HGN test discussed above, the officer is looking for distinct “clues” of impairment.
The WAT test has eight distinct clues.
- First, the officer will look to see if the subject is able to keep balance while listening to the instructions. If the subject cannot maintain the heel-to-toe position during the instruction stage, this is a “clue.”
- Second, the officer will look to see if the subject begins the test before the instructions are finished. If the subject begins before being told to do so, this is a “clue.”
- Third, the officer will look to see if the subject stops while she is walking. If the person stops for several seconds during the test, this is a “clue.”
- Fourth, the officer will look to see if the subject fails to touch her heel to her toe with each step. If the subject leaves more than one-half inch between her heel and her toe on any step, this is a “clue.”
- Fifth, the officer will look to see if the subject steps off of the imaginary line upon which she is walking. If she steps so that one of her feet is entirely off of the line, this is a “clue.”
- Sixth, the officer will look to see if the subject is using her arms to balance while walking. If she raises one or both of her arms more than 6 inches from her side while walking, this is a “clue.”
- Seventh, the officer will look to see if the subject turns improperly. As mentioned above, a proper turn is quite unnatural and somewhat complicated—the subject must leave her front foot on the line while using her back foot to take a series of small steps to turn. If she pivots or spins around, this is a “clue.” Finally, the officer will look to see if the subject takes an incorrect number of steps. If she takes fewer or more than nine steps, this is a “clue.”
The National Highway Traffic Safety Administration (NHTSA) says that research shows that if just two or more clues are evident, or the subject fails to complete this test, it is likely that the subject’s blood alcohol concentration is above a .10.
What is the One Leg Stand test?
When administering the OLS test, the officer will instruct the subject to stand with his/her feet together and her arms down at her sides. The officer will then demonstrate the correct position. The officer will instruct the subject not to start the test until he tells her to do so. The officer will ask the subject if she understands the instructions thus far. The officer will then proceed to verbally explain the test requirements while also giving a physical demonstration. The officer will instruct the subject that when he tells her to begin, she should raise one leg (it does not matter which leg) until her foot is 6 inches above the ground when raised parallel. He will instruct the subject to keep her arms straight and her hands at her sides while counting out loud in the following manner: “one thousand and one, one thousand and two, one thousand and three…” The officer will instruct the subject to keep her eyes on her raised foot during this test. The test typically lasts for 30 seconds.
How is the One Leg Stand test scored?
Like in the other two standardized tests, the officer is looking for distinct “clues” of impairment. The OLS test has four total clues. First, the officer will look to see if the subject sways while balancing. Swaying is a “clue” of impairment. Second, the officer will look to see if the subject uses her arms for balance while performing this test. Using one’s arms for balance constitutes a “clue” of impairment. Third, the officer will look to see if the subject is able to keep one foot off the ground without hopping on the other foot in an attempt to maintain balance. Hopping while performing the test is considered a “clue.” Finally, the officer will look to see if the subject is able to maintain the one-leg stand position without putting the other foot down one or more times during a 30 second count. If the subject puts her foot down during the test it is considered a “clue.” If two or more clues are present, or the subject fails to complete the test, the NHTSA states that there “is a good chance the [person’s] blood alcohol concentration is above .10.”
Challenging Your DUI Charge
Field sobriety tests are notoriously bad indicators of intoxication. Judging these tests is a highly subjective process, which has led to countless false DUI accusations.
Subjective FSTs Equals False DUI Charges
- Accuracy rates among studies vary widely. So in an effort to provide law enforcement with roadside tools for assessing the suspicion of DUI, the National Highway Traffic Safety Administration (NHTSA) developed standardized testing procedures for the top three FSTs: Horizontal Gaze Nystagmus (HGN), Walk and Turn, and One Leg Stand (watch these FSTs). The goal was to develop a consistent reliable point system and properly train law enforcement to administer standard procedures. However, the new point system is still subjective.
- Studies show that the three standardized FSTs were found to only be 65-77% effective, leaving their results open to dispute in court proceedings. (NHTSA studies had a higher accuracy rate for these tests. Which are right?)
- Also, the National Highway Transportation Safety Administration (NHTSA) admits if “any of the standardized field sobriety test elements is changed, the validity is compromised.” According to the National Association of Criminal Defense, “a number of courts have held that if not properly administered, the field sobriety tests are inadmissible.
- Given the inaccuracy of roadside sobriety tests, many people are wrongly accused of DUI. Moreover, very few officers actually conduct roadside sobriety tests in accordance with established procedures.
Call Today for Your FREE DUI Consultation
If you’ve been arrested and charged with a DUI based on your performance during a field sobriety test that led to the accumulation of additional evidence against you, contact us for a no-cost, immediate case consultation. During our initial consultation, we will help you determine if you should plead guilty or not guilty to your charge. Contact us today at 803-252-4800.