New Jersey Field Sobriety Tests – Horizontal Gaze Nystagmus
Summary: In New Jersey, police often use the horizontal gaze nystagmus test as a field sobriety test on the side of the road. This test is often used to establish probable cause for a DWI arrest, but a lawyer can help present a strong defense for you if you’ve been taken into custody as a result of this test.
When you have been pulled over by the police and are suspected of driving while intoxicated in New Jersey, the police may administer field sobriety tests before arresting you for drunk driving. Police can use either standardized tests or non-standardized field sobriety tests in New Jersey, even though only the former are supported by the National Highway Traffic Safety Administration (NHTSA).
The horizontal gaze nystagmus (HGN) test is one of three standardized field sobriety tests recognized by the NHTSA. While it cannot be admitted into court in New Jersey as proof of guilt for DWI, police still administer it on the side of the road and may use it as probable cause to make an arrest.
Understanding the Horizontal Gaze Nystagmus Test
The term “horizontal gaze nystagmus” refers to involuntary jerks and movements in the eyes as a person moves them from side to side. The test is based on the proposition that if a person has a higher blood alcohol content (BAC), his or her eyes will jerk more rapidly when they move from side to side.
Police administering this test will direct a driver to follow some small item with only their eyes as it moves from side to side. For example, the officer will use a pen tip or some other small, precise object. The driver will be directed to keep their head still and use only their eyes to follow the object’s movements. As they move the object, police watch the driver’s eyes for jerkiness and a lack of smoothness. In particular, they watch for eye jerking as the gaze reaches its farthest point as well as jerking that happens before the eye reaches a 45-degree perspective.
How Police Score the Horizontal Gaze Nystagmus Test
Each time the police notice this kind of indication, they record it as a “clue.” There are six possible clues that can be recorded during the test, and if a driver has a score of four or greater, a police officer will state that this means that there is a 77 percent chance that the driver is intoxicated. While these tests cannot be used in court, they can be used to make a probable cause for a DUI arrest based on the belief that the driver’s BAC is at or above the legal limit of 0.08.
While there is a scientific basis and procedure associated with the HGN test, it is rife with error and false interpretations. While alcohol or drug intoxication can indeed increase nystagmus, the phenomenon is universal. In addition, injuries, fatigue and illness can also make the nystagmus effect more pronounced.
HGN to Measure Sobriety
When people consume alcohol to the point of intoxication, it can cause both mental and physical effects and impairments. However, the mental impairments are noticeable long before any physical impairments become obvious. This means that field sobriety tests that focus on physical issues may be more likely to pick up on other physical problems, illnesses or disabilities rather than intoxication by alcohol or drugs.
In addition, police frequently conduct the test in an improper manner. As these tests are conducted by the side of the road, police may hold the test while the driver sits inside his or her vehicle with the head turned at a 45-degree angle. This runs contrary to the standard instructions for the test, which requires that both the head and body face the object being used to stimulate the gaze.
Defend Yourself From DUI Charges
If you’ve been arrested for DWI on the basis of a horizontal gaze nystagmus test, you may be deeply worried about your future and how these charges can affect your job, family life and ability to drive. You can rest assured that these results are not admissible as proof of guilt, but police and prosecutors may plan to introduce other evidence in court. An experienced New Jersey DUI defense attorney can work with you to challenge police and prosecution assertions and put forward a strong defense.
Prosecutors must prove beyond a reasonable doubt that you drove while intoxicated. The flaws in these tests and other evidence could provide a strong basis to introduce doubt into the equation and help you avoid a conviction. Call the office of Denis F. Driscoll today to make an appointment for a consultation.