Field Sobriety Tests

It is NEVER a good idea to perform the FSTs

The good thing about FSTs is that THEY ARE OPTIONAL! Of course the officer administering the tests is very unlikely to actually tell the suspect s/he does not have to perform them, but YOU CAN AND SHOULD REFUSE TO PERFORM THEM.

During FSTs, officers look for the littlest of clues to indicate the suspect is “intoxicated” or “under the influence,” and often will not give clear instructions to the suspect or tell him/her what they are actually looking for.

Furthermore, the “indicators” the officers look for to conclude and later testify that a driver is intoxicated are often clues that do not even mean the person is intoxicated. For instance, an officer will mark the fact that a suspect raises his/her arms for balance during the one-leg-stand or walk-and-turn test as a sign of alcohol or drug impairment. In reality, this is just a natural and instinctive action any person, sober or intoxicated, would take to maintain balance.

As stated above, the main purpose an officer conducts the FSTs is to gather evidence against the suspect to use against him/her at trial. The officer is not looking for indications that you are actually sober and okay to legally drive a car. The FSTs and their administration are laced with subjectivity making it very easy for the officer to mark down “indicators” of intoxication and conclude you are under the influence. Therefore, even if you think you’ll “pass” the FSTs, it is best not to perform them.

The Standardized Field Sobriety Tests

Although there are many FSTs that police officers have used in the past, and many times still use today, there are only three that have been “standardized” by the National Highway Traffic Safety Administration (NHTSA). These three tests are called the “Walk-and-Turn,” the “One-Leg-Stand,” and the “Horizontal Gaze Nystagmus (HGN).” NHTSA standardized these three tests because studies showed the others were not reliable for determining whether or not someone was under the influence of alcohol. In fact, the other tests could not predict impairment any better than a coin flip, which is great news for any DUI defendant where the arresting officer(s) administered any non-standardized FSTs. The NHTSA standardized tests, however, have been found to have somewhat of a scientific base for reliability if administered properly.

Despite their higher standard of reliability than other FSTs, a good and experienced DUI defense attorney can still challenge the standardized tests, both before and during trial. A good DUI defense attorney may be able to get the FSTs invalidated and tossed out before trial, depending on the circumstances of the case. If the court rules the FSTs are admissible, however, a good DUI defense attorney will still bring out important evidence at trial to bring doubt into the jurors’ minds as to the accuracy of the tests.

Here is a breakdown of the three NHTSA Standardized FSTs:

Walk-and-Turn Test

The walk-and-turn test, aka the “heel-to-toe” test, is a coordination test and a mental test and must be conducted on a flat surface. The suspect begins this test by standing heel-to-toe with his/her arms at the sides while listening to the officer’s instructions and watching his/her demonstration of the test. The suspect then takes 9 heel-to-toe (heel touching the toe) steps along a straight line while counting the steps out loud. This line will either be real, using something marked on the roadway, or it will be imaginary. The suspect must keep his/her arms at the sides throughout the test and look at his/her feet while walking. When the suspect has taken 9 steps forward, s/he must turn around in the manner the officer has instructed and return with 9 steps in the same heel-to-toe manner along the same line. The suspect must not stop walking until the test is completed.

During the Walk-and-Turn, the officer is looking to see if the suspect is physically coordinated enough to complete the task and if the suspect has the mental capacity to understand, remember, and follow the verbal instructions.

While the officer is giving the instructions, s/he looks to see if the suspect:

Cannot maintain balance in the awkward heel-to-toe stance
Starts the test too soon

Clues the officer looks for while the suspect is walking are if the suspect:

Stops walking
Misses heel-to-toe
Steps off the line
Uses arms to balance
Turns improperly
Takes the wrong number of steps

One-Leg-Stand Test

Like the Walk-and-Turn, the One-Leg-Stand test must be conducted on a relatively smooth flat surface. While the officer instructs the suspect, the suspect must stand straight with feet together and arms down at the sides. When the officer finishes instructing the suspect, the suspect must raise one leg approximately 6 inches off the ground, extending the raised leg outward in a stiff-leg manner with the toes pointed straight ahead and foot parallel to the ground. The suspect must stare at the elevated foot, maintain balance on the other foot, and count out loud in a designated manner for 30 seconds. This tests the suspect’s ability to divide his/her attention between balancing, listening, and counting out loud, which can be very difficult for someone who is impaired.

As with the Walk-and-Turn, officers will look to see if the suspect can follow instructions, such as waiting until instructed to begin to actually begin the test. Once the suspect raises his/her leg as instructed, the officer will observe to see if the suspect:

Sways
Uses arms to balance
Hops
Puts his/her foot down

Horizontal Gaze Nystagmus (HGN)

Nystagmus is defined as an involuntary jerking of the eyes. This occurs in people who have consumed alcohol. It is not something they can control or are even aware of.

The HGN test is viewed as the most scientific and trustworthy of the standardized FSTs. In this test, the officer will hold his/her finger or an object (a stimulus) 12-15 inches directly in front of the suspect’s face, and 2 or 3 inches above the eyes. The officer instructs the suspect to keep his/her head still and follow the object with his/her eyes. The officer will slowly and smoothly move the stimulus all the way out to the suspect’s left, then all the way to the suspect’s right, then back to the center. While moving the stimulus, the officer observes the suspect’s eyes to see if they track evenly.

The officer will then hold the stimulus in the center and observe the suspect’s pupil size.

Next, the officer will move the stimulus back out to the suspect’s extreme left then extreme right. This time, s/he will observe for “lack of smooth pursuit” in each eye, meaning the eyes jerk as they move to follow the stimulus.

Next, the officer will hold the stimulus all the way out to the suspect’s extreme left, then all the way out to the suspect’s extreme right. While holding the stimulus to the extremes, the officer will look for a distinct and unmistakable jerking of the eye while it gazes to the side. The jerking the officers are looking for is stronger and more distinct than the natural jerking that occurs in people who have not consumed any alcohol.

The final clue the officers look for in the HGN test is the “onset of nystagmus prior to 45 degrees.” The officers observe this clue if the eye jerking that occurs when the suspect gazes to the side begins before the stimulus is at a 45 degree angle to the suspect’s face.

In total, officers look for 6 clues in the HGN test:

Lack of smooth pursuit in the left eye
Lack of smooth pursuit in the right eye
Distinct nystagmus at maximum deviation in the left eye
Distinct nystagmus at maximum deviation in the right eye
Angle of onset prior to 45 degrees in the left eye
Angle of onset prior to 45 degrees in the right eye

Studies have shown that 77% of subjects tested who exhibit 4 or more of these clues have a blood alcohol concentration between 0.0 and 0.10.

Although the HGN test is known as the most scientifically accurate and trustworthy indicator of impairment, a skilled and experienced DUI attorney can challenge its accuracy. For instance, studies have invalidated the belief that an officer administering the test can accurately determine an actual BAC in the suspect. The presence of the clues, even all 6 clues, is only an indicator that SOME alcohol was consumed, not an indicator that the driver is impaired or above a 0.08 BAC.

Certain factors may also invalidate the accuracy of a given HGN test. For instance, if the officer did not conduct the test in the proper fashion, its accuracy cannot be trusted. Also, if the suspect has one of several medical conditions, his/her eyes may be affected and cause some clues of nystagmus without any alcohol at all.