One of the primary tools used by officers in a DUI arrest is
field sobriety tests such as the horizontal gaze nystagmus. The horizontal gaze nystagmus test
is one of the few field sobriety tests verified for accuracy by the National
Highway Traffic Safety Administration (NHTSA). This test seems relatively
straightforward—the suspect is asked to track a beam of light that
the officer moves back and forth with his pocket flashlight. The officer
watches to see if the suspect's eye movement is smooth or if he displays
nystagmus, which is the involuntary jerking of the eye.
All people will display some nystagmus at some point during the test, usually
when the beam of light is about 40 degrees from dead-on. However, alcohol
is known to make this nystagmus happen sooner and more dramatically. If
the arresting officer claims that you have failed a horizontal gaze nystagmus
test, an Orange County DUI defense attorney can still fight your charges.
The validity of a test depends on the proper administration of it, the
qualifications of the officer administering it, and corroboration by other
tests. If your lawyer can find issue with any of these factors, the test
may be rendered invalid.
Even with all of those factors check out, it is important to remember that
the horizontal gaze nystagmus test is only 77% accurate. With this in
mind, your attorney can introduce reasonable doubt to the state by pressing
these factors during cross-examination. They may ask the officer to recount
every step he took when administering the test, and if the officer is
unable to recall any part of the procedure, reasonable doubt could be
introduced. They may ask an unqualified officer about his qualifications
or ask that the officer verify that he failed to corroborate the results
of the test.
Creating Reasonable Doubt During Cross-Examination
The procedure for administering the horizontal nystagmus test has 25 separate
steps. As a result, many officers make mistakes. However, most would never
admit to making a mistake if asked directly. Luckily, there is a simple
method commonly employed by defense attorneys to garner such an admission.
During cross examination, they can ask the officer about each step in
the procedure and emphasizes every point where the officer claims to forget
or be unsure.
These questions may be about:
- Specific details regarding the procedure of the tests
- The officer's preparation for the test
- The objects that the officer used during the test
- The directions they gave to the defendant during the test
Your Orange County DUI lawyer may also intersperse questions about common
mistakes among questions about proper test procedure, just to make sure
the officer is not just mindlessly confirming his answers. Ironically,
the officer could do everything perfectly while administering the horizontal
gaze nystagmus test and the results could still be inaccurate. Numerous
medical conditions can cause a false positive on the horizontal nystagmus
test, such as fatigue, hypertension, and caffeine usage.
This horizontal gaze nystagmus test is an essentially a medical exam, and
the person administering it needs the medical expertise to differentiate
an aberrant level of nystagmus from a natural one. The person must also
take into account other potential causes of aberrant nystagmus besides
alcohol. Because of this, it is possible to attack an arrest based on
the results of this test by illustrating the officer's lack of medical
expertise to the jury. The Law Office of Barney B. Gibbs knows this tactic
and others like it, so you can trust that will give you a fair chance
at fighting your
Failing a field sobriety test is not a death sentence for your case. An
experienced attorney can still fight the charges. Call The Law Offices
of Barney B. Gibbs today for a
free initial consultation.