Although there are several FSTs that officers use, only three have been scientifically validated. The National Highways Traffic Safety Administration (NHTSA) is an organization that was designed to research and set guidelines for the proper administration of field sobriety tests. Law enforcement officers are trained in these tests, both how to administer them and what cues (clues) to look for in the subjects performing the tests. These tests must be administered and interpreted in the same prescribed manner, which is what makes them considered “standardized.”
NHTSA describes these tests as psychophysical tests, which is commonly described as "divided attention tests." These are the tests the officers use to assess a subject's mental and physical impairment. An officer is immediately looking for possible cues of impairment, from the time they observe driving, to the initial face to face contact with a subject, to the time they administer field sobriety tests.
HGN is basically an involuntary jerking of the eyes, as they gaze toward the side of each direction. When a person is impaired, the involuntary jerking of the eyes becomes noticeable. As BAC levels move higher, the eyes jerk sooner when moving toward the side.
An officer administering the HGN test asks the subject to follow the movement of a "stimulus" (usually a pen) with the eyes only. Many people will commonly move their heads, which is always marked down as not following directions and suggests mental impairment.
The officer is supposed to examine each eye for three specific cues. The stimulus is waived in front of the subject from side to side in each direction. The officer notes the physical cues and any other signs of mental impairment as well, to provide evidence of impairment to support their arrest. The three cues an officer is looking for in the HGN test are:
- Alcohol impairment causes your eyes to noticeably jerk when moving from side to side, as opposed to moving smoothly. Officers often note lack of smooth pursuit in each eye, which counts as two cues. (one cue for each eye)
- Alcohol impairment causes your eyes to jerk distinctly when it moves as far to the side as possible and held there for several seconds. Officers often note distinct and sustained nystagmus at maximum deviation in each eye, which counts as two cues. (one cue for each eye)
- Alcohol impairment causes your eyes to start jerking prior to a 45 degree angle when moving towards a side. Officers often note onset of nystagmus prior to 45 degrees in each eye, which counts as two cues. (one cue for each eye)
The officer is looking for four or more cues in this test. The maximum is three cues per eye, six cues total. If a subject exhibits four or more cues, this indicates that the subject may be under the influence of alcohol.
The HGN test is generally utilized by the officer and the prosecutor as the most reliable field sobriety test because it is based on involuntary physical movements. An untrained attorney would not know how to weaken the strength of this type of evidence against you. However, a trained, skilled, experienced DUI attorney knows how to demonstrate the lack of scientific merit in the HGN test.
We know how to properly cross examine an officer and we have the background certification training in field sobriety tests that allows us to challenge their administration of the test. Officers are not Optometrists or Ophthalmologists, and we are able to expose their lack of scientific knowledge behind the purpose of an HGN test. Finally, it is important to know the statistical data that NHTSA provided based on its research because this test is not even close to 100% accurate, even when properly administered.
The one leg stand test is considered a divided attention test, and has been validated through NHTSA’s research programs. This test consists of two stages; 1.) The instructional stage 2.) Balance and counting stage.
In the instructional stage, a subject must stand with their feet together, keep their hands at their sides, and listen to instructions. This test divided attention because the subject must maintain balance while listening and memorizing instructions.
In the balance and counting stage, a subject must lift one leg approximately 6 inches off the ground, and while looking at the raised foot count out loud in the following way: “One thousand and one, one thousand and two…” until told to stop. The officer is suppose to keep time for a 30 second period and then end the test. The four cues that the officer is looking for are:
- Subject sways during test
- Subject uses arm to balance
- Subject hops
- Subject puts foot down
The officer is looking for two or more cues in this test. If a subject exhibits two or more cues, this indicates that the subject may be under the influence of alcohol. The attorneys at The Law Office of Ben Mironer know the various aspects of this test that make it difficult for any sober person to do, which shows how unreliable this test actually is. Furthermore, we know why this test is nowhere near 100% accurate, even when properly administered.
The walk and turn test is considered a divided attention test, and has been validated through NHTSA’s research programs. This test consists of two stages; 1.) The instructional stage 2.) Walking stage.
In the instructional stage, a subject must stand with their feet in a heel to toe position, keep their hands at their sides, and listen to instructions. This not only requires undivided attention, but also a very good sense of balance.
In the walking stage, a subject is instructed to take 9 heel to toe steps in a straight line (sometimes the line is imaginary), then turn in a manner demonstrated by the officer, and take 9 heel to toe steps back, all while counting the steps out loud and watching their feet. The officer administering the test is looking for 8 various cues in the subject:
- Subject can’t balance during instructions
- Subject starts too soon
- Subject stops while walking
- Subject doesn’t touch heel to toe
- Subject steps off line
- Subject uses arms to balance
- Subject loses balance on turn or turn incorrectly
- Subject takes the wrong number of steps
The officer is looking for two or more cues in this test. If a subject exhibits two or more cues, this indicates that the subject may be under the influence of alcohol. The attorneys at The Law Office of Ben Mironer know how difficult this test is to perform, even by a sober person.
It is critical to fully understand and conceptualize this test because a good DUI attorney can explain how well a subject may demonstrate mental and physical ability simply by completing this test. Furthermore, it is important to note that a subject can only exhibit a cue once, meaning if you step off the line two times, that is only one cue, not two.
Finally, this test is also not even close to 100% accurate, even when properly administered. The statistical data is something that we use in our favor because these tests are inconclusive even when properly administered. These tests may show the presence of alcohol in the system, but they are not clear in regard to showing alcohol impairment.
Field sobriety tests are used by officers to obtain additional evidence of impairment against a subject. An officer must have sufficient probable cause to make a lawful arrest, and they use field sobriety test evidence to support their finding of probable cause to arrest. If your attorney can demonstrate that there was insufficient probable cause for the officer to make the arrest, then the case can get dismissed after a successful suppression motion.
In a DUI case, an attorney at The Law Office of Ben Mironer could have a major impact on the result of the case because we have the knowledge and skills to negotiate and litigate DUI cases to get the best possible outcome.