Standardized Field Sobriety Tests: What Law Enforcement Officials Use To Keep The Roads Safe
Do you know what SFSTs are and how California courts deal with
those that don’t follow the NHTSA’s guidelines? SFSTs is short for
Standard Field Sobriety Tests and they’re ordered by police to persons
who are suspected to be under the influence of alcohol or drugs during
a suspected DUI stop.
The National Highway Traffic and Safety Administration (or NHTSA) has
completed exhaustive studies on these tests so that law officials can
figure out how intoxicated a person is. Police agencies around the
United States have used them for many years to cultivate probable cause
for a person’s arrest as well as evidence to be used in court for the
suspect’s conviction.
It’s important to understand that not all of the tests are
scientifically designed to be the best precise indicators of alcohol
intoxication. However, the NHTSA has come up with three FSTs that are
the best indicators to determine one’s level of intoxication when it’s
completed in a standardized manner, which are known as SFSTs.
1 – Horizontal Gaze
Nystagmus (or HGN)
This is an eye test that is more than 75 percent precise to determine
if a person’s blood alcohol content is more than .10 percent. It
involves the involuntary jerking of a suspect’s eyes at a specific
angle, usually to the side.
2 – Walk and Turn (or WAT)
This is test involves walking and is about 68 percent precise to
determine a BAC level of .10 percent or more.
3 – One-Leg Stand (or OLS)
This test is completed by having the suspect remain in one place with
one leg up. It’s about 65 percent precise in determining the BAC is
above .10 percent.
When HGN is used in conjunction with WAT, there is an accuracy rate of
80 percent to figuring out the BAC is above .10 percent.
Now, both the OLS and WAT test are considered divided
attention tests. These are given to determine if a suspect is listening
to and following instructions while doing simple physical movements.
Supposedly, sober persons can do these tests with no difficulty while
impaired persons have problems with it.
Now, police agencies will use both FSTs and SFSTs to determine if a
person is indeed under the influence. However, using SFSTs is
advantageous because they’re backed by science. FSTs are not backed by
science to conclude whether or not a person is drinking. Some
FST examples include:
- Alphabet test
- Hand pat
- Count down
- Finger to nose
- Rhomberg Balancing test
While they’re not backed by science, the majority of courts will allow
them as evidence. In California courts, they’re admissible but the
defense attorney can attack the evidence by challenging them. Many
other states will only permit the scientific based SFSTs in court to be
used as evidence.
(2 votes, 3.50 / 5)