An arrest for driving under the influence (DUI) in Illinois typically begins with a DUI stop. A police officer may suspect that you are driving under the influence if you are swerving, changing lanes suddenly, or driving too slow. If the officer suspects you are intoxicated, he will pull you over. However, an officer may stop you for violating another traffic law such as speeding or having a broken brake light. After stopping you for the traffic offense, if the officer suspects you are intoxicated, the traffic stop will turn into a DUI stop.
Regardless of why you are pulled over, if the officer suspects you have been drinking, he will conduct a series of field sobriety tests to look for “clues” or signs that you are intoxicated. These tests are used to determine if probable cause exists for a DUI arrest. One of the standardized field sobriety tests used by law enforcement officers is the Horizontal Gaze Nystagmus (HGN) test.
What is the Horizontal Gaze Nystagmus Test?
The HGN test is one of the three standardized field sobriety tests thought to be reliable in determining if a person is intoxicated. The National Highway Traffic Safety Administration (NHTSA) has developed specific instructions for administering this test. If the test is administered according to these instructions, there should be visible signs of impairment if the driver has been drinking alcohol.
Nystagmus is a medical term used to describe the involuntary jerking of the eye. If a person follows an object with his eyes and nystagmus appears before the object reaches a 45-degree angle to the eye, this is an indication of intoxication. This is why an officer asks you to follow an object, such as a penlight, with your eyes at a DUI stop. The officer is looking for nystagmus to appear in either eye as the object passes the 45-degree angle.
There are two other signs that an officer is looking for when he asks you to follow an object with your eyes. The first is whether the eye moves smoothly as it follows the object. The second is whether nystagmus appears after the eye has moved as far to the corner as possible.
Challenging the Results of an HGN Test at a DUI Stop
Even if the officer finds probable cause to arrest you at a DUI stop, you can challenge the results of the field sobriety tests. There are several other reasons why a driver may show signs of nystagmus in addition to intoxication. For example, certain medications and medical conditions can cause nystagmus. Brain injuries and certain seizure medications can cause nystagmus. Nystagmus can even be caused by your contact lenses.
Another cause of nystagmus is flashing or bright lights shining in the person’s face during the test. If the officer performs the HGN test at a DUI stop where the lights of oncoming traffic are shining in the driver’s face, the lights could cause nystagmus to be present even though the driver may not be intoxicated.
The final issue with the HGN test is that some officers fail to follow the instructions provided by the NHTSA. If the officer does not follow the instructions precisely for performing the HGN test, the officer may note false signs of alcohol impairment. Based on the false signs, the officer may assume he has probable cause for an arrest.
It is important to contact our attorneys as soon as possible if you are arrested at a DUI stop. There are defenses to DUI arrests that can be used to possibly dismiss the charges or reduce the charges.
Contact Our Office for a Consultation with an Experienced Illinois DUI Attorney
The DUI lawyers of Pioletti Pioletti & Nichols represent individuals who need help with a DUI arrest. We assist clients throughout McLean, Woodford, Tazewell, and Peoria counties by providing compassionate, competent legal services. Contact our office at 309-938-4838 to schedule your free consultation.
When you need the assistance of an experienced criminal defense attorney in central Illinois, call Pioletti Pioletti & Nichols. We are dedicated to providing our clients with exceptional service and support throughout the DUI process.