What Exactly is a Field Sobriety Test?
There are only three field sobriety tests recognized by the National Highway and Traffic Safety Administration (NHTSA) as “valid” standardized tests. However, to be “valid” these tests MUST be administered by the officer in the manner prescribed and standardized by NHTSA. These Standardized Field Sobriety Tests or SFSTs are the:
• Horizontal Gaze Nystagmus
• Walk and Turn
• One Leg Stand
While the police officer may have given you other tests, these are the only three tests that have been validated by the NHTSA.
Police officers use these tests as a means to indicate whether you have been driving under the influence of alcohol or other drugs. Physical conditions that affect your brain, eyes or parts of your body that involve standing or walking may negatively affect your performance on these tests, whether you have consumed alcohol or not.
The Horizontal Gaze Nystagmus
If the police asked you to step out of the car and had you follow a stimulus with your eyes, they were administering the Horizontal Gaze Nystagmus test. During this field sobriety test, the officer is looking for the following symptoms:
• Jerking of the eyeball at rest, or while following the stimulus
• Jerking of the eyeball at the farthest point it can move to the side.
• Jerking as the eyeball moves to the side before it gets to a 45 degree angle
Nystagmus can be caused by many things other than intoxication. Nystagmus can also be caused by head injuries, rotation of the body, temperature differences from one ear to the other, a foreign fluid in the blood, objects moving into and out of sight, traffic driving by, strobe lights, tired eyes, brain tumors, brain damage, and inner ear disorders, to name a few.
The Walk and Turn
Picture if you will an “imaginary line”. It’s not so easy, is it? Now picture a police officer quickly throwing countless instructions at you with no opportunity to practice! This is the Walk and Turn field sobriety test. Imagining a straight line (or on an actual line), you must take nine heel-to-toe steps up then back, count each step out loud, keep your hands at your sides, keep your eyes watching your feet, and turn correctly. If you do more than ONE of any of the following, you have failed:
• Cannot keep balance during instruction phase
• Start the test too early
• Step “off” the imaginary (or real) line
• Miss touching heel to toe on any step
• Stop walking during the test
• Use your arms to balance
• Raise your arms from your sides by more than six inches
• Make an incorrect number of steps
• Make an “improper” turn
One Leg Stand
As in the Walk and Turn, with the One Leg Stand field sobriety test, you receive quick instructions with no chance to practice first. You must do the following: raise one leg six inches from the ground, keeping both legs straight with your raised foot parallel to the ground, keeping your arms at your sides while counting, "one thousand and one, one thousand and two" and so forth until told to stop. More than ONE of these occurrences and you fail:
• If you sway while balancing
• If you raise your arms
• If you put your foot down
• If you hop
The good news in all of this is that Ms. Callahan is a trained NHTSA SFST administrator. If the officer improperly administered your tests, or if they were not done voluntarily, Ms. Callahan will vigorously cross-examine the officer for his or her sloppy lack of attention to proper procedures and failure to conduct the tests in the required manner. This can seriously undermine the officer’s credibility and could lead to an acquittal, dismissal or a reduced charge.