 Police
Officers use
Field Sobriety
Evaluations
as a significant
tool in DUI
detection.
Finger-to-nose,
reciting the
alphabet,
day, date,
and time estimates
have all been
used by officers.
However, only
three evaluations
have been
studied, tested
and approved
by the National
Highway Traffic
Safety Administration
(NHTSA). Those
three evaluations
are the “Horizontal
Gaze Nystagmus”,
“Walk
and Turn”
and “One-Leg
Stand.”
HORIZONTAL
GAZE NYSTAGMUS
Horizontal
Gaze Nystagmus
(HGN) is
described
as an involuntary
jerking
of the eye,
which may
(or may
not) be
caused by
the ingestion
of an alcoholic
beverage.
The testing
officer
will ask
the subject
to stand
with his
hands at
his sides,
feet together.
A stimulus,
usually
a pen or
finger,
is held
12-15 inches
from the
subject’s
eyes, at
slightly
above eye
level. The
subject
is instructed
to follow
the stimulus
with their
eyes only,
not moving
their head.
The officer
will move
the stimulus
back and
forth in
front of
the subject’s
eyes.
During
the evaluation,
the officer
observes
the eye
for involuntary
jerking
or Nystagmus.
The officer
checks for
six clues,
three for
each eye.
He makes
twelve passes
in front
of the eyes
checking
each clue
twice. The
clues are:
(1) lack
of smooth
pursuit,
(2) distinct
nystagmus
at maximum
deviation
and (3)
onset of
nystagmus
prior to
forty-five
degrees.
On this
evaluation,
four clues
indicated
impairment.
Horizontal
Gaze Nystagmus
is recognized
in Georgia
as a “scientific”
test. Brain
damage,
seizure
medications,
inhalants
and other
depressants
may also
cause nystagmus.
WALK
AND TURN
The Walk
and Turn
is an evaluation
consisting
of eight
clues. The
arresting
officer
instructs
the subject
to place
their feet
heel to
toe on a
line (sometimes
imaginary)
with their
right foot
ahead of
the left.
The subject
should hold
this position
while the
officer
instructs
and demonstrates
the evaluation.
If the subject
cannot keep
their balance
or starts
the evaluation
too soon,
a clue will
be assessed.
The officer
instructs
subjects
to walk
heel-to-toe
down the
line keep
their arms
at their
sides. After
taking nine
steps, execute
a turn making
several
small steps,
and make
nine heel-to-toe
steps back.
During the
walking
stage, if
the subject:
stops walking,
misses heel-to-toe,
steps off
the line,
raises an
arm more
than six
inches,
takes the
incorrect
number of
steps or
executes
an improper
turn, a
clue will
be assessed.
Any two
of the eight
possible
clues indicates
impairment.
The Walk
and Turn
evaluation
may not
be appropriate
for individuals
over 60
years old
or more
than 50
pounds overweight.
ONE-LEG
STAND
Like the
Walk and
Turn, the
One-Leg
Stand evaluation
is a divided
attention
test. On
the One-Leg
Stand evaluation,
the testing
officer
will ask
that the
subject
stand with
their feet
together
and hands
at their
sides. The
subject
is instructed
to raise
a foot six
inches off
the ground
and count
out loud
to thirty.
he One-Leg
Stand is
a four clue
evaluation.
The testing
officer
scores a
clue if
the subject:
sways, raises
arms for
balance,
hops or
places their
foot on
the ground.
Any two
of these
clues indicates
impairment.
If you
would like
to get the
process
started
with your
case, please
complete
the DUI
Case Questionnaire.
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