Lexington Field Sobriety Tests

There are three standardized field sobriety tests that officers use to determine whether someone is under the influence of drugs or alcohol. These tests include the horizontal gaze nystagmus test, walk and turn test, and one-leg stand test.

Read below to learn more about Lexington field sobriety tests. And if you have any questions, reach out to an experienced DUI lawyer.

Horizontal Gaze Nystagmus Test

One of the Lexington field sobriety tests is the horizontal gaze nystagmus, which is commonly referred to as the HGN test. In this test, the police officer holds either a flashlight or a pen and tells the person to follow the object with their eyes. The officer is looking for an involuntary jerking of the eyeball, and if they are showing nystagmus, it is an indicator of impairment, meaning they could be under the influence of something. However, this is not an exact science because there are at least 38 known causes of nystagmus, including staying up late or a head injury.

The National Highway Traffic Safety Administration has a manual that lays out those three field sobriety tests, and it gives specific instructions for the officer conducting the test. It says they should look at whether the person has delayed-onset nystagmus, whether they are able to hold vertical nystagmus, whether there is the jerking of the eyeball, how long the test takes, and how many passes of the pen across the person’s eyes. The officer must follow the instruction for the test verbatim to have any validity. However, juries have no clue as far as the accuracy of horizontal gaze nystagmus tests.

What is the Walk-and-Turn Test?

The walk-and-turn test also has very specific instructions in the NHTSA manual that must be followed in detail. It is a test that has the person walk nine steps, heel to toe, and with their arms by their side. If the person does not follow the instructions perfectly, the officer will consider that one of the indicators of impairment. If the person does not strike heel to toe perfectly, does not walk perfectly on the line, or uses their arms to balance, the officer will use that against them as another indicator of impairment.

The officer might say they did not follow directions and that they did not touch heel to toe perfectly, but many people will have problems walking heel to toe, especially when nervous and having to do it on the side of the road.

One-Leg Stand Test

The one-leg stand test is basically what it is called, is standing on one leg as instructed by the NHTSA manual, and it is one in which those instructions must be given perfectly or its accuracy can be challenged. The person must have their arms down by their side, lift a one leg about six inches off the ground, and hold it while counting, until the officer tells them to stop, generally for about 20 or 30 seconds. Like the other tests, the one-leg stand test is not accurate enough to establish whether an individual was for sure under the influence.

Also, there are non-standardized field sobriety tests that an officer may use. No type of research has ever been done with one of these non-standardized field sobriety tests and they are highly fallible.

For more information about Lexington field sobriety tests, get in touch with an accomplished lawyer today.