Now I use the word “Standardized” because these three (3) test are the only ones backed by science and accepted in the courts are being eligible to determine impairment. That being said, there are other Field Sobriety tests but these three (3) are the only ones at this time that are considered “Standardized”. Today we will explore the three (3) test giving a short synapsis of the process that would take place during the testing phase.
The three (3) Standardized Field Sobriety tests are as follows: Horizontal Gaze Nystagmus, Walk & Turn, and the One Leg stand. They must be done in that order to be valid, and the subject being tested must understand the instructions being given for the results to be valid.
Let’s start with the Horizontal Gaze Nystagmus test, during this phase of testing the subject in question is asked to follow the tip of the Officers pin or other object that can be seen easily. The subject is to use his/her eyes only and follow the directions given until the completion of the test. This test is based off the Nystagmus and its visible presence in those that consume alcohol or drugs. For those who don’t know, Nystagmus is the involuntary jerking of the eyes that is visible upon consumption of a certain amount of alcohol or from the consumption of certain drugs.
Next, the Walk & Turn; during this test the subject in question will be placed in a specific walking style stance, they will be asked to image a solid line, then asked to take nine (9) heel to toe steps forward, then turn around, and take nine (9) heel to toe steps back. Again, they also will be told specific instructions to follow throughout the duration of the test. This test is about coordination, balance, and the ability to follow instructions. Due to the effects of alcohol or drugs on the brain this test is very effective in showing impairment.
Lastly, the One Leg Stand test; during this test the subject in question will be given specific instructions and asked not to begin until told to do so. The subject will be asked to raise either his/her right or left leg off the ground approximately six (6) inches and hold it there. The subject will be asked to keep the bottom of his/her foot parallel to the ground, and count aloud in a specific manner until told to stop. This test examines the subjects balance, coordination, and fine motor function under stress. Again, these aspects are impaired under the influence of alcohol or drugs hence this test is very good at determining impairment.
The overall point is to determine enough probable cause to believe that the subject in question is under the influence of either alcohol or drugs and with that be able to justify taking them to jail for operating a motor vehicle while impaired.
There are other components that go into this investigation, but I will stop here and continue this discussion at a later time.
Word from the wise, know your state of mind and ability when getting behind the wheel of a vehicle because if not someone could end up hurt or even dead.
"Standardized" Field Sobriety Test…
