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The Standardized Field Sobriety Test (SFST)
battery is composed of three tests: Horizontal Gaze Nystagmus (HGN),
Walk-and-Turn (WAT), and One-Leg Stand (OLS). The tests were
developed by the
National Highway Traffic Safety
Administration (NHTSA) in the late 1970's. In 1981, law
enforcement officers began using NHTSA's Standardized Field Sobriety
Test (SFST) battery on the roadside to help determine whether motorists
who are suspected of DWI have blood alcohol concentrations (BACs)
greater than 0.10 percent. Since 1981, however, many states
including Texas have implemented laws that define DWI at BACs below
0.10. Texas is now using the 0.08 standard.
The validity of SFST results is
dependent upon officers following the established, standardized
procedures for test administration and scoring. According to NHTSA
when properly administered and scored, under laboratory conditions,
SFSTs accurately identify intoxicated
drivers as follows:
•
HGN - 77%
• WAT - 68%
• OLS - 65%
This means that even under laboratory
conditions, the HGN was wrong 23% of the time, the WAT 32% and the
OLS 35 times out of 100. Additionally, NHTSA's own research emphasizes
that test results are valid only when administered in strict
compliance with NHTSA protocol. If any one of the standardized field
sobriety elements is changed, the validity is compromised. It is
therefore imperative to have your attorney review the manner in
which the SFSTs was administered. Your lawyer may be able to
suppress the results of an improperly administered test which would
reduce the State's chance of convicting you of DWI.
Remember, Dax worked
in law enforcement for over 2.5 years and actually administered
SFSTs on the side of the road. Based off those results, he
made arrests. He has testified in cases and been a witness in
DWI ALR hearings. Few other attorneys have this experience, so
Dax really knows what to look for and can help you!
HGN - Horizontal Gaze Nystagmus
"Nystagmus" means an involuntary
jerking of the eyes. HGN refers to an involuntary jerking occurring
as the eyes gaze toward the side. In addition to being involuntary,
the person experiencing the nystagmus is unaware that the jerking is
happening. The theory behind the test is that nystagmus becomes
readily noticeable when a person is impaired.
In
administering the test the officer has the subject follow the motion of
a stimulus with the eyes only. The stimulus may be the tip of a pen or
penlight, an eraser on a pencil or a fingertip. As the eyes move from
side to side each eye is examined for three specific clues:
• Lack of Smooth Pursuit - does
the eye move smoothly or does it jerk noticeably?
• Distinct Nystagmus at Maximum
Deviation - when the eye moves as far to the side as possible and is
kept at that position for several seconds, does it jerk distinctly?
• Onset of Nystagmus Prior to 45% - as
the eye moves to the side, does it start to jerk prior to a 45%
angle?
Officers frequently fail to properly
administer the HGN. It is crucially important for your attorney to
review the video, if available, to ascertain whether the test was
properly administered or whether suppression of the results is
possible.
Walk and Turn
The WAT is a divided attention test
consisting of two stages: Instruction Stage; and Walking Stage. In
the instruction stage, the subject must stand with their feet in
heel-to-toe position, keep their arms at their sides, and listen to
instructions. The subject must maintain the heel-to-toe position and
may not begin walking until all instructions are given. In the
Walking Stage the subject takes nine heel-to-toe steps, turns in a
prescribed manner, and takes nine heel-to-toe steps back, while
counting out loud and watching their feet. Officers observe the
subject's performance for eight clues:
• can't balance during instructions
• starts too soon
• stops while walking
• doesn't touch heel to toe
• steps off line
• uses arms for balance
• loses balance on turn or turns
incorrectly; and
• takes the wrong number of steps
A subject who exhibits two or more
clues will fail the test. Scoring is entirely subjective and within
the officer's discretion, but this is where the video is very
important because it allows your attorney and anyone else to view
your performance and see what the officer is testifying to regarding
your performance.
One Legged Stand
The OLS is also divided into two
stages. In the Instruction Stage, the subject must stand with feet
together, keep arms at side and listen to instructions. In the
Balance
and Counting Stage, the subject must raise the leg of his
choice approximately 6 inches off the ground, toes pointed out,
keeping legs straight. While looking at the
elevated foot, count out
load in the following manner: "one thousand and one", "one thousand
and two", etc, until told to stop. The officer will instruct the
subject to stop after 30 seconds. The subject is observed for the
following clues:
• sways while balancing
• uses arms to balance
• hops
• puts foot down
A subject who exhibits 2 or more clues,
as determined by the officer, will fail the test.
Romberg Balance Test
Person is instructed to stand with feet
together, head tipped back, eyes closed, arms at side. Position is
demonstrated. The officer is observing anterior-posterior sway for
approximately 30 seconds.
This
is not one of the "Standardized" Field Sobriety Tests. Typically
estimating 30 seconds within 5 seconds either way is considered
good, anything outside of a 5 second margin of error will be counted
as a sign of intoxication. The officer will also look for swaying
during this time.
Breath Test - Chemical Test
Under Texas law an individual is
legally intoxicated if his/her alcohol concentration is .08 or
greater. A person's alcohol concentration can be determined by
testing the blood, urine or breath. "Alcohol concentration" means
the number of grams of alcohol per:
a. 210 liters of breath;
b. 100 milliliters of blood; or
c. 67 milliliters of urine.
Blood testing is generally considered
to be the most reliable and accurate, while urine tests are regarded
as the least precise. If you are arrested for DWI in Texas you will
most likely be asked to give a sample of your breath. Breath testing
is the most commonly utilized method because it is the least
expensive to administer. The scientific community is sharply divided
over the accuracy and reliability of breath testing procedures. The
police do not save the sample of breath tested. Thus it is not
available for re-testing by an independent laboratory. When
asked to provide a sample, you should REFUSE, even though you will
lose your driving privilege without obtaining an occupational
license.
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