St. Louis DWI Lawyer
An important note to begin this section: the field sobriety tests are not mandatory. A person can choose not to participate in the field sobriety tests, which helps limit the amount of evidence against him during the DWI investigation. If a person is intoxicated, then participating in the field sobriety tests may not be a good idea because the results of the tests will not be favorable and the person can look poor on the video if the incident is recorded by a police officer’s dashboard camera. If a person chooses not to perform the field sobriety tests, it is important to be polite to the officer and calmly say, “I was told by an attorney not to take the field sobriety tests.” Many times the officer will make an effort to talk the person into participating in the field sobriety tests. Even when this happens, no further explanation is necessary when refusing to take the field sobriety tests.
Many people think of field sobriety tests as a series of stupid human tricks that include walking a straight line and reciting the alphabet backwards. As with many things, there is some truth and some fiction to this general perception of field sobriety tests. For example, only three of the tests are standardized, which gives those three tests at least some degree of scientific backing. The other tests, including counting backwards and doing the alphabet, are not standardized and are only considered general observations.
The three tests that have been standardized by the National Highway Traffic Safety Administration (NHTSA) are:
- Horizontal Gaze Nystagmus
- Walk and Turn
- One Leg Stand
Examples of field sobriety tests that have not been standardized and therefore lack any proper scientific foundation include:
- Counting (generally backwards)
- Finger to Nose
In the following sections, there will be an in depth breakdown of the proper way the standardized field sobriety tests should be administered, as well as common deficiencies and defenses associated with those tests. Then there will be a more general discussion of the non-standardized tests to explain when they are used, how they are administered, and finally, whether they have any real evidentiary value at all.
Horizontal Gaze Nystagmus (HGN)
The horizontal gaze nystagmus test is commonly referred to as HGN, and it is the only one of the three standardized field sobriety tests that does not involve balance. The HGN test examines a suspect’s eyes for involuntary movements, called nystagmus, that are an indication of alcohol intoxication. It is important to note that although intoxication from alcohol and other central nervous system depressants may cause nystagmus, intoxication from other kinds of drugs do not cause this type of nystagmus.
The administration of the HGN test is more complicated than the administration of the other two standardized field sobriety tests because there are timing requirements that must be followed. Basically, the administering police officer moves a stimulus, usually his finger, back and forth in front of a suspect’s face while the suspect follows the stimulus with his eyes. During the test the administering officer is looking for an involuntary jerking, called nystagmus, of the suspect’s eyeballs. The HGN test involves very little up front instruction to the suspect, but then the administering police officer must follow specific timing for his hand movements as he goes through the test.
During the test the officer is looking for nystagmus during three distinct phases:
- Lack of Smooth Pursuit
- Distinct and Sustained Nystagmus at Maximum Deviation
- Onset of Nystagmus Prior to 45 Degrees
The officer will examine both eyes for each of these three clues, which results in a total of six clues for the HGN test. The presence of four or more clues is an indication of the suspect’s intoxication.
The shortcomings of the HGN test are its reliance on a) the improper administration of the test by the police officer, and (b) the credibility of the police officer’s observations while scoring the test. Unlike the observations from the other field sobriety tests, a dash camera from a patrol vehicle is not going to be able to pick up any possible involuntary jerking of the suspect’s eyes during the HGN test, which leaves attorneys, judges, and jurors left only with the police officer’s word about what he saw while administering and scoring the test.
A person is only a candidate for the HGN test if the person’s pupils are the same size and can track equally. Equal tracking is when both eyes and sweep side to side at the same rate while following the stimulus and this should be tested by the police officer administering the HGN test, prior to checking for the above three clues. Additionally, the officer must also check to make sure there is no resting nystagmus. Resting nystagmus is when a person displays nystagmus even when his eyes are simply staring straight ahead. If a person has resting nystagmus, eyes that do not track equally, or pupils that are not the same size, then he is not a candidate for the HGN test.
Walk and Turn Test
The Walk and Turn test is the second of the field sobriety tests that have been standardized by NHTSA. This is one of the tests people commonly think of when it comes to field sobriety tests and most assume it simply requires walking a straight line. Unfortunately for participants of the test, it is quite a bit more complicated than simply walking a straight line. A person who is asked to perform the Walk and Turn test must take nine heel to toe steps down a straight line (which is sometimes an imaginary straight line), turn around in a very specific manner, then walk nine heel to toe steps back down the same line. There are eight total clues a police officer is looking for when administering the Walk and Turn test.
- Cannot maintain a heel to toe stance
- Starts before instructed to begin
- Stops while walking to steady self
- Steps off line
- Uses arms for balance
- Fails to touch heel to toe
- Improper turn or loses balance while turning
- Incorrect number of step
The presence of two or more of the above eight clues is considered an indication of intoxication
By looking at the clues it is clear that not all of the clues have to do with physical balance. Many of the clues have to do with specifically following the police officer’s instructions. Clues such as “starts before instructed to begin” or “incorrect number of steps” are clues designed to determine if a person can remember the officer’s instructions while also performing the balance portion of the test. The Walk and Turn test, as well as the One Leg Stand test, are referred to as divided attention tasks, because the person is given specific instructions he must remember while also performing a physical challenge. The tests are designed this way because driving a car is also a divided attention task. While driving a person has to perform physical activities such as steering and working the pedals, while simultaneously thinking about his destination and the actions of the other cars.
Like all field sobriety tests, the Walk and Turn test is only as good as the police officer who administers the test. The police officer must give specific instructions so the person knows what to do during the test. If the police officer forgets to tell the person not to use his arms for balance, then it would be unfair to mark it as a clue when the person does use his arms for balance. Here are the specific instructions that should be given by a police officer administering the Walk and Turn test:
“Place your left foot on the line. Place your right foot on the line ahead of your left foot, with heel of your right foot against toe of left foot. Place your arms down at your sides. Maintain this position until I have completed the instructions. Do not start to walk until told to do so. Do you understand the instructions so far?
“When I tell you to start, take nine heel-to-toe steps, turn, and take nine heel –to-toe steps back. When you turn, keep the front foot on the line, and turn by taking a series of small steps with the other foot, like this. While you are walking, keep your arms at your sides, watch your feet at all times, and count your steps out loud. Once you start walking, don’t stop until you have completed the test. Do you understand the instructions? Begin, and count your first step from the heel-to-toe position as ‘One.’”
The police officer should also demonstrate each portion of the instructions as he is verbally explaining the test. These instructions are complicated to begin with, but they are even more complicated when first heard during a roadside stop. It is easy to see how people can miss one or two instructions from the police officer and then fail the test for not properly following the instructions and displaying some of the eight possible clues.
One Leg Stand Test
The last of the three standardized field sobriety tests is the One Leg Stand test. The One Leg Stand test is exactly what it sounds like. This is the test where the police officer has a suspect stand on one leg while the officer looks for a series of four clues. The four clues the administering police officer is looking for during the One Leg Stand are:
- Sways while balancing
- Uses arms for balance
- Puts foot down
Just like the Walk and Turn test, the presence of two or more clues during the One Leg Stand test would indicate the suspect is intoxicated. Here are the specific instructions that should be given by a police officer administering the One Leg Stand test:
“When I tell you to start, raise one leg, either leg, with the foot approximately six inches off the ground, keeping your raised foot parallel to the ground. You must keep both legs straight, arms at your side. While holding that position, count out loud in the following manner: ‘one thousand and one, one thousand and two, one thousand and three, until told to stop.’ Keep your arms at your side at all times and keep watching the raised foot. Do you understand? Go ahead and perform the test.”
Although not as complex as the instructions for the Walk and Turn test, there are still plenty of areas for confusion for a person hearing these instructions for the first time. Out of the three standardized field sobriety tests that have been explained, this is the test people are most likely to pass based on my experience. Even when a person passes this test, the police officer still always indicate that the person swayed while balancing. I do not believe I have ever looked at a police report in a DWI case where the One Leg Stand was administered and the police officer did not mark Sways While Balancing as a clue he observed. It is only one small example of all the practical issues that exist with the administration of standardized field sobriety tests roadside during a DWI investigation.
St. Louis DWI Lawyer Jason Korner
If you or a loved one has been arrested for Driving While Intoxicated, then please contact our office today at 314-409-2659 or click here to fill our the contact form. The days after an arrest are scary, but the scariest part is the anxiety from not knowing what to expect. Let Mr. Korner answer all of your questions, and help you start moving forward with your defense.