The Horizontal Gaze Nystagmus (HGN) Test is an essential part of the field sobriety tests administered by police officers persons suspected of drunk driving. A failed field sobriety test in Nevada could be indicative of intoxication and lead to an arrest.
As the name suggests, the HGN is an eye exam used to test the gaze of the suspect. Although you don’t have to agree to the test, the results of the HGN, along with several other tests, like the preliminary breath test, can be used in court to show there was probable cause to make an arrest for DUI.
Drunk driving is against the law in Nevada, and although this test might not be the most precise measurement of intoxication, it is still widely used throughout the state.
Defining the Horizontal Gaze Nystagmus
The HGN is utilized in most Nevada DUI cases. It is a part of the three individual measures of sobriety within the field sobriety test. Any time a police officer suspects a driver for drunk driving, they are allowed to administer the test. However, you may politely decline as you have no legal obligation to perform this test.
The HGN involves the officer holding up an object, usually their finger or penlight, in front of the suspect’s eyes. The suspect is then instructed to follow the object with their eyes as the officer moves it from left to right.
The officer is usually looking for involuntary jerking of the pupils, also called nystagmus. If the pupils jerk a specific number of times, the police might assume the suspect has a blood alcohol content that is higher than the legal limit (0.08% or higher).
Administering the Test
You may wonder when the Horizontal Gaze Nystagmus (HGN) Test is administered. Usually, the test occurs around 10 to 30 minutes after the police first make contact with the driver. Only people who are suspected by the officer would be asked to perform this test.
Picture this:
A car is picking up speed down the I-15 and is soon spotted by a Nevada Highway Patrol officer. This leads the officer to pull the driver over, followed by the officer asking for their license and registration. This is a routine request which is used to determine whether the driver has any warrants out for arrest. During this time, the officer has observed the driver’s eyes (checking to see if they are bloodshot or glassy), their breath (officers usually check for the odor of alcohol), and their mannerisms (intoxicated drivers normally speak in a slurred manner or have slower movements).
The officer will also go so far as to ask the driver whether they are drunk. In case the officer finds reason to believe the driver is intoxicated, they will ask them to exit the car and perform the field sobriety tests, which consist of the HGN along with the walk and turn test and the one-legged stand. This may also be followed by the preliminary breath test. Failing the test may lead to an arrest for DUI.
Since the police officers aren’t allowed to administer the test if the driver is too incapacitated, the evaluation might be postponed.
The Methods
The HGN can only be administered by a trained Nevada police officer. Even officers must follow certain instructions. Otherwise, the test cannot be used in court. The first important rule is that the officer must stand in front of the suspect with their weapons away from the suspect. They should also explain to the suspect that they will check the suspect’s eyes. This may require the suspect to remove anything obstructing their vision.
This is usually followed by the officer holding a stimulus, such as a penlight, 12 to 15 inches away from the suspect’s eyes. They usually begin by explaining that they will move the stimulus from side to side horizontally and ask the suspect to follow with their pupils while keeping their head still. This allows the officer to test the suspect on three levels:
- The smoothness of eye movement: The officer requires the subject to follow the stimulus without their pupils jerking.
- Distinct and sustained nystagmus: The officer may take the stimulus away to the side, as far as the suspect’s pupils are able to turn outward (maximum deviation) and hold for several seconds. This allows them to monitor how distinct and sustained the involuntary pupil jerking really is.
- The onset of nystagmus prior to 45 degrees: The officer would simply move the stimulus to the sides and check for nystagmus (involuntary jerking) before the 45-degree angle is reached.
All of these are applicable to both eyes, and scores are given accordingly.
HGN FAQs
Here are some frequently asked questions regarding HGN to help you understand the test:
How Do I Know If I Have Failed?
The results of the sobriety test aren’t always accurate. However, it is important to know what the office is looking for. The Nevada police usually watch out for three nystagmus clues in each eye (6 overall). According to the NHTSA (National Highway Traffic Safety Administration), four or more clues usually indicate intoxication. A passing HGN score, on the other hand, would be anything below four clues.
Do I Have to Take the HGN?
The HGN is a part of the field sobriety tests commonly administered by police officers in Nevada. However, the state of Nevada does not require you to take the HGN. It is advisable for a suspect to politely decline the field sobriety tests, including the HGN, as that can reduce the evidence the prosecution presents in court.
However, you must remember that the refusal of a field sobriety test may lead the officer to suspicion, which might result in an arrest and a chemical test, which could either be a breath test or a blood test.
Does Passing the Test or Refusing to Take It Help a Suspect Avoid Arrest?
A suspect can receive a DUI charge even if they pass the HGN. The HGN test is only one indicator, and suspects are usually subjected to other tests that may indicate intoxication. The combined results and even the officer’s general suspicion could lead to a DUI arrest.
Failing the HGN doesn’t always lead to an arrest. Since nystagmus can be caused by a number of other factors, the officer may let the suspect go. This is especially true when there are no other signs of intoxication.
In some cases, the driver might refuse to take the test or be too incapacitated to respond. Here, the police might arrest them for DUI based solely on the other evidence. Thus, a DUI conviction is possible without the HGN test.
Is the Test Accurate?
No, the test isn’t always reliable, and even the NHTSA backs this claim. The test is only reliable 77% of the time. Thus, one out of four people might be falsely accused of intoxication based on the HGN.
This means you can contest the results of the HGN test. Your DUI defense attorney can help you with the contestation. The following arguments can strengthen your case:
Arguments Relating to the Officer
It is easy for a defense attorney to prove officer negligence. They can make arguments regarding insufficiency of the officer’s training and whether they were properly administering the test at the time. They can also mention specifics, such as how far the stimulus was held (too close or too far could lead to inaccuracy).
Moreover, defense attorneys can also argue that the officer’s eye level wasn’t above the driver’s, that the officer’s hand was jerky, that the 45-degree angle wasn’t correctly measured, or simply that the officer wasn’t good at giving instructions. All of these can be supported by evidence produced from the officer’s dashcam.
Arguments Relating to the Suspect
Defense attorneys can also support the suspect in certain ways, including arguing that the suspect was on certain medications that led to nystagmus (these include seizure medication, PCP, anti-depressants, barbiturates, and more).
They can also argue the case with the help of certain head injuries or eye disorders, discomfort caused by contact lenses, or flashing lights in the external environment.
These arguments might not lead to the DUI charges being dropped since cases are reviewed in their entirety. However, the more flaws the defense attorneys can find in the overall argument, the better the case for the defendant.
HGN Tests: A Valuable Evidence in Nevada DUI Court
The HGN tests are permitted and recognized by Nevada law. In fact, they are usually studied to determine whether the driver was under the influence at the time. For example, State, Dept. of Motor Vehicles and Public Safety v. McLeod maintained that administering the HGN tests on a driver with a head injury was justified since they showed other signs of intoxication.
These signs included the odor of alcohol along with bloodshot eyes. Since the driver seemed to be under the influence, the HGN test was allowed.
Field Sobriety Tests
The HGN isn’t the only field sobriety test but a small part of a bigger whole. The field sobriety test includes three standardized tests. Along with the HGN, you may also need to take the one-legged stand test and the walk-and-turn test. However, the HGN is regarded as the most reliable.
Even if a suspect fails the HGN, it doesn’t guarantee a DUI conviction. Careful analysis and further proceedings may bring other evidence to light that can lead to a reduced sentence.
Contact BLG Wins for More Information
Have you failed the HGN test and are facing drunk driving charges in Nevada? Our seasoned attorneys at The Bourassa Law Group can help. Call for a consultation and work with our team to handle your case with the care and expertise that you deserve.