What is the HGN Field Sobriety Test?

Author: Joe Pioletti Posted on: . Filed in: DUI.

When a driver is stopped by law enforcement officers in Illinois under the suspension of driving under the influence (DUI), the officer typically performs a variety of field sobriety tests, including the HGN field sobriety test, to determine if an arrest for DUI is justified. There are three standardized field sobriety tests used by law enforcement agencies throughout the United States and in Illinois. These standardized tests were developed under the supervision of the National Highway Traffic Safety Administration (NHTSA).

The Horizontal Gaze Nystagmus or HGN field sobriety test is one of the three tests used by officers to determine if a driver is impaired. The HGN field sobriety test measures the driver’s nystagmus. Nystagmus is an involuntary jerking or bouncing of the eye due to a disturbance in the brain’s ability to control eye movements. The use of alcohol effects the ability of the brain to control the eye muscle; therefore, if a person has been drinking, he or she will exhibit signs of nystagmus. Theoretically, the more alcohol the person has had, the more pronounced the eye movements are during the test.

Challenging the Results of the HGN Field Sobriety Test

Even though the courts have held that evidence from an HGN field sobriety test is admissible when performed by a properly trained officer in accordance with the protocols established by the NHTSA, several defenses may be used by the defendant to discount the results of the HGN field sobriety test. For example, there are other conditions that may cause a person to exhibit nystagmus other than the consumption of alcohol.

Another defense lies with the officer performing the test. If the officer has not received proper training or if he fails to perform the test in accordance with the protocols established by the NHTSA, the results of the test may be challenged as valid. Tests that are performed where the driver is in the direct line of sight of oncoming traffic or other bright lights can also give a false positive for nystagmus. If an officer performs the HGN field sobriety test under these conditions, the driver may exhibit signs of nystagmus even though he has not had any alcohol to drink.

As experienced DUI attorneys, we understand how to defend cases that are based on field sobriety tests. It is very important that you contact our office as soon as possible to discuss the possible defenses to your DUI charge. A DUI conviction carries severe penalties including potential jail time, fines and suspension of your license.

Contact Our Office for a Consultation with an Experienced Illinois DUI Attorney

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Pioletti & Pioletti is a full service law firm that represents individuals who need experienced DUI defense attorneys. With offices located in Eureka and Bloomington, we represent clients throughout Woodford County and McLean County. We offer free consultations. You can contact our office by calling 309-938-4838.

When you need the assistance of an experienced criminal defense attorney in Central Illinois, call the compassionate and skilled attorneys of Pioletti & Pioletti. We are dedicated to giving our clients exceptional service and support throughout the DUI process.

Joe Pioletti

Joe Pioletti

Attorney Joe C. Pioletti was born and raised in Eureka, IL.Joe received his Bachelor of Arts Degree in Business Management from Eureka College where he also minored in Spanish.Joe then received his Juris Doctor from Southern Illinois University School of Law.While in law school Joe worked in the Domestic Violence Advocacy Clinic and was a three-time recipient of the Charter Class Campaign for Academic Excellence Scholarship.
Joe Pioletti