Nashville BAC Test Lawyer

Field Sobriety Tests (FST) which are offered by police officials, are designed for failure. Most people cannot perform these FST’s perfectly even when sober.

The three tests most commonly used are:

(1) The Horizontal Gaze Nystagmus test,
(2) The Walk and Turn test, and
(3) The One Legged Stand test.

According to The National Highway Traffic Safety Administration (NHTSA) these tests are only accurate in predicting BAC when:

The tests are performed in the agreed, consistent manner
The same clues are used to assess the suspects performance
The consistent criteria are employed to interpret that performance

The Standardized Field Sobriety Tests are not flexible. They must be administered exactly the same every single time.

1.The Horizontal Gaze Nystagmus Test (HGN)
Nystagmus is a natural, normal phenomenon involving the involuntary jerking of the eyes. Alcohol and certain other drugs do not cause nystagmus, but may exaggerate or magnify it. The officer will hold a pen or a light 12-15 inches from your face and slowly move it to the left and then right.
2. The Walk and Turn Test
The following are the NHTSA standardized clues which may indicate intoxication on the Walk-and-Turn Test:
- Unable to maintain balanced while listening to instructions
- Starts before instructions are finished being explained
- Stops while walking
- Does not touch heel-to-toe
- Steps off the line
- Uses arms to maintain balance
- Improper Turn
3. One Legged Stand Test
When performing this test, the officer looks for the following clues:
- The suspect sways while balancing (the side-to-side or back-and-forth motion)
- Uses arms for balance (moving 6 or more inches from the side of the body to help keep balance)
- Hopping
- Puts foot down