Understanding DUI Arrests in Georgia and the Horizontal Gaze Nystagmus Test

The Horizontal Gaze Nystagmus (HGN) test is one of three standardized field sobriety tests (SFSTs) validated by the National Highway Traffic Safety Administration (NHTSA) to, when administered properly, show the presence of alcohol in a driver suspected to be impaired. It is also a test that police administer frequently during traffic stops when they are investigating a potentially impaired driver. Though the NHTSA recognizes the HGN test as a test that can indicate the presence of alcohol or other central nervous system depressant, this test is not fool-proof and is often administered improperly.

As an expert DUI defense attorney, we will thoroughly investigate your case, including the types of and manner in which field sobriety tests like the HGN test were administered. A proper DUI defense requires an expert understanding of the nuances of this test, its potential for inaccuracies, and the factors that can undermine its reliability as evidence of impairment.  At Owens Law, P.C., we use our skills and resources to ensure you receive the best representation possible. Contact us at (678) 470-7638 to schedule an initial consultation and learn more about how we will help you fight your DUI charge to its conclusion.

What is a Horizontal Gaze Nystagmus Test (HGN) in Fulton County, Georgia?

Nystagmus is a term used to describe an involuntary jerking or twitching of the eyes that becomes more pronounced after a person has ingested alcohol or other central nervous system depressant.  The Horizontal Gaze Nystagmus Test (HGN)  is one of three standardized field sobriety tests used by the police in Georgia to determine whether a driver is under the unlawful influence of alcohol or drugs.

How is the HGN Test Performed?

The HGN test is meant to measure the involuntary jerking of the eye – known as nystagmus. A driver who has consumed alcohol or other central nervous system depressant may exhibit nystagmus as the driver gazes toward the side while following a stimulus, like a pen or another object.

The police officer should tell the driver to stand still, place his or her hands by their side, and keep his or her head still. Then they must be properly instructed to look at a stimulus and follow it with both eyes while the officer moves the stimulus side to side.

Ways to Challenge the HGN Test in DeKalb County, Georgia.

HGN tests can be challenged effectively by arguing against their reliability (these tests are highly subjective) or proving improper administration of the test (these tests require following strict and specific technical rules). Also, these tests can be challenged based on matters not associated with the test itself, but matters related to the driver or to the environment.

Common Challenges to the HGN Test

• Unreliable based on police officer's subjective estimations and preconceived notions
• Unreliable based on police officer's failure to administer the test properly
• Unreliable based on external factors