STANDARDIZED FIELD SOBRIETY TESTS
A client once referred to the standardized field sobriety tests as “those silly tests that the cops make drivers perform on the side of the highway”. The implication of that statement is that the tests have no rational basis. However, if the tests are performed correctly, judges accept the results as evidence of impairment.
Thanks to organizations like the National Highway Traffic Safety Agency (“NHTSA”) and Mothers Against Drunk Drivers (“MADD”), law officers nationwide are on the lookout for drivers who are impaired by alcohol and other drugs. NHTSA has provided the training to catch and prosecute impaired drivers. MADD has mounted a nationwide movement to assure that impaired drivers are not only caught but are also punished.
NHTSA mounted a systematic approach to the identification of impaired drivers in the mid-1970s. At that time, law enforcement officers across the nation used an ad hoc basis for determining whether a given driver was impaired by alcohol. At that time there were a number of tests that were administered to drivers who were believed to have been driving while impaired by alcohol.
As one such test, the officer would drop a number of coins on the street and direct the driver to pick up the coins. It was believed that an impaired driver would not have the dexterity to retrieve the coins without stumbling or fumbling.
Another test required the driver to attempt to draw a circle on a piece of paper with a pen. The lack of symmetry of the circle was believed to demonstrate impairment.
Another test required the driver to recite backwards from a certain specified odd number to another specified odd number. It was believed that alcohol impairment would be demonstrated by the driver’s inability to concentrate and thus count incorrectly.
A further approach was to require a driver to recite the abc’s from a given letter other than “a” and ending with a letter other than “z”. A further approach required the driver to stand with eyes closed, with head tilted backward and attempt to touch the driver’s nose with the tip of his or her finger.
Other common tests for impairment included the horizontal gaze nystagmus, the walk and turn and the one leg stand tests.
NHTSA set out to determine whether any or all of such tests would consistently and accurately demonstrate impairment. It funded research for three specific studies in an attempt to validate a method to accurately judge a driver for impairment. When those tests yielded positive results, it funded additional tests in the 1990’s.
After spending a great deal of money, NHTSA concluded that there were only three tests that validly, consistently and accurately demonstrated driver impairment, those being the horizontal gaze nystagmus test, the walk and turn test and the one leg stand test. After reaching that conclusion, NHTSA set out to standardize the procedures by which those tests should be performed, to standardize the “clues” that demonstrated impairment and to standardize how the test was to be graded.
Those validated tests are generically referred to as the “standardized field sobriety tests”. As the name suggests, standardization requires that the tests be administered, judged and graded in a specific manner and order. Standardization requires the officer to administer the horizontal nystagmus test first, the walk and turn test next and the one leg stand test last.
Horizontal Gaze Nystagmus. Alcohol and other central nervous system depressants cause a condition known as “horizontal nystagmus”. Horizontal Nystagmus is defined as the involuntary jerking of the eyes as they gaze toward the side of the head. Nystagmus cannot be controlled and is capable of clearly demonstrating impairment.
To administer the horizontal gaze nystagmus (“HGN”) test, the officer will instruct the driver to stand up straight with heels together while looking forward. The officer will then position an object such as a pen or pen light directly in front of the driver’s nose and slightly above the driver’s eye level. The officer will instruct the driver to follow the tip of the pen or pen light with only the eyes while keeping the head still.
The officer will first view the driver’s eyes to determine whether pupil are the same size and whether the eyes jerk while looking forward. If those conditions are not present, the officer will then make two complete passes of the pen or pen light from its starting position in the middle of the face toward the driver’s left, then toward the driver’s right. The officer will be checking to determine whether the eyes tract equally.
The officer is looking for three clues: lack of smooth pursuit; distinct and sustained nystagmus at maximum deviation; and, onset of nystagmus prior to 45 degrees. Each eye may demonstrate none or all three of the clues. Each eye will be checked twice and separately for the presence of each clue.
Lack of smooth pursuit. The officer will then make two complete passes of the pen or pen light from its starting position in the middle of the face toward the driver’s left, then toward the driver’s right. The officer will then repeat the movement (two passes) to check to determine whether the driver’s eyes smoothly pursue the pen or pen light.
Distinct and sustained nystagmus at maximum deviation. The officer will then make two additional passes to determine whether the driver’s eyes jerk horizontally while looking toward the side as far as the eyes will turn. Officers are trying to determine if horizontal nystagmus (sideway jerking) exists at the maximum deviation (looking to side as far as physically possible) after the eyes have held that position for a minimum of four seconds.
Onset of nystagmus prior to 45 degrees. Finally, the officer will attempt to determine whether the jerking begins prior to the point where the eyes are turned sideways to 45 degrees.
The officer is looking for the presence of those three clues in each eye. Each eye may demonstrate none or all three of the clues. A driver who is judged to have four clues will be considered impaired.
Although it is easy to recite the procedures that must be followed, courtroom experience has taught that only officers with a great deal of experience in administering the HGN test can administer the test proficiently. In many jurisdictions, officers receive very little if any training and thus do not administer the test correctly. When questioned about the results of the HGN test, a poorly trained officer will be able to recite the three clues but will not be able to demonstrate the proper administration of the test.
A HGN test that is improperly administered is not a good indicator of impairment. However, a HGN test properly administered will provide test results that correctly identify impairment approximately 88% of the time. However, many judges give little or no credence to testimony from officers concerning the results of the HGN test. Perhaps this reflects an attitude that the officers are not sufficiently trained to administer and judge the results of the test.
Walk and Turn. Standardization requires the walk and turn test to be administered next. There are two stages of this test, the instruction stage and the walking stage. During the instruction stage, the driver will be advised: To assume a heel to toe stance with the right foot being the front foot; To place arms at the sides; Do not start until told to start; Imagine a straight line; To take nine heel to toe steps on the imaginary line beginning with the left foot, turn around by taking a series of small steps with the right foot and take nine heel to toe steps back; To keep watching his or her feet; To keep his or her arms to the side; To count steps out loud; and, Do not stop walking until the test is completed. The next stage is the walking stage and begins when the office advises the driver to start.
There are eight clues of impairment. The first two clues may occur during the instruction stage. Those clues are observed when the driver cannot maintain his or her balance while in the heel to toe stance and when the driver starts walking prior to be told to do so. The remaining six clues may occur during the walking stage of the test. Those clues are observed when the driver stops walking prior to finishing the test, when the driver misses a heel to toe step, when the driver steps completely off the line, when the driver raises both arms six inches or more from his side, when the driver makes an improper turn, and when the driver takes an incorrect number of steps.
The studies performed by NHTSA determined that 79% of the drivers who exhibited two or more clues during this test were impaired. Most judges give a great deal of credence to the testimony of officers concerning the walk and turn test. Perhaps one reason is that quite often the test is captured on electronic media and thus can be readily seen by the judge.
One leg stand. Standardization requires the one leg test to be administered next. There are two stages of this test, the instruction stage and the balancing and counting stage. During the instruction stage, the driver will be advised to: Stand straight; place feet together; keep arms at side; and, Maintain position until told otherwise. During the balancing and counting stage, the driver will be advised to: Raise either leg; Keep the raised foot approximately 6 inches off the ground; Keep both legs straight and arms at his or her side; Keep eyes on the raised foot; Count out loud in the following manner, one thousand one, one thousand two and so on until told to stop. The officer will then time the driver for 30 seconds.
There are four clues of impairment concerning the one leg stand test. Those clues are demonstrated when the driver puts his foot down prior to be instructed to do so by the officer, when the driver uses his arms to balance, when the driver sways during his performance and when the driver hops to keep from putting his foot down.
The studies performed by NHTSA determined that 83% of the drivers who exhibited two or more clues during this test were impaired. Most judges give a great deal of credence to the testimony of officers concerning the one leg stand test. As with the walk and turn test, perhaps one reason is that quite often the one leg stand test is captured on electronic media and thus can be readily observed by the judge.