If you have recently been arrested for driving under the influence, you
were likely asked to take a field sobriety test when you were first stopped
by a police officer. The officer probably noticed you exhibiting signs
that you were intoxicated while driving your vehicle, which gave them
“reasonable suspicion” to stop you. In order to establish
full “probable cause,” they likely conducted these tests with
you, which confirmed their suspicions and allowed them to make the arrest.
However, many people are shocked at just how many mistakes are made when
it comes to wrongful DUI arrests, along with just how shockingly inaccurate
field sobriety tests are.
The Three Most Common Field Sobriety Tests
Back in the late 1970s, the NHTSA and Southern California Research Institute
conducted a series of studies in order to establish the most accurate
and reliable field sobriety tests, as well as develop standards for administering
them. The goal was to minimize errors in issuing these tests and successfully
prosecute people who were driving drunk. The SCRI came up with three tests: the
horizontal gaze nystagmus test, the
one-leg stand test, and the
walk and turn test. While combined with each other yielded better results, these tests
on their own are surprisingly inaccurate.
Horizontal Gaze Nystagmus
In this test, the officer holds an object up at about eye level to the
driver and then asks them to follow it with their eyes while keeping their
head still. An intoxicated individual will lose some of their ability
to control their eye muscles, resulting in twitching. However, those who
are dyslexic or have other inhibitions will have difficulty performing
this task, making it accurate only about 77 percent of the time.
The one-leg stand test involves standing on one leg, pointing the toes
of your raised leg upward, and then looking towards the sky while performing
a mental task, usually counting backwards from 30. The goal is to get
you to mix physical and mental requirements, which most intoxicated brains
struggle with. Sound difficult to do while sober? Try it. It is. For this
reason, even when conducted properly, the study found that this test was
only accurate 65 percent of the time.
Walk and Turn
To find out more about field sobriety tests and how accurate they are,
call the Law offices of Mark Girdner today at (209) 326-1533 and ask for a
This test involves walking a certain number of steps in a straight line
in heel-to-toe fashion, as though you were walking on a balance beam.
Once you have walked that number of steps, you then must turn without
lifting your feet, and walk the same number of steps back. The goal is
both to test balance and to see how well you can process instructions
on the fly at the same time. The SCRI found that once standardized, this
test was only accurate about 68 percent of the time.