Standard Field Sobriety Tests guidelines

Drunk Driving & DWI conviction


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.

 
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