When a Pennsylvania police officer pulls you over in traffic and tells you to step out of your vehicle, it suggests that you’re suspected of intoxication. The events that unfold from that moment on may not only have an impact on the rest of your day, but your future as well. To make a DUI arrest, a police officer must first establish probable cause.
Probable cause refers to evidence that you have committed a crime — in this case, drunk or drugged driving. To establish cause in a DUI stop, a police officer will often ask a driver to take a field sobriety test. One of the most common types of sobriety tests is the Horizontal Gaze Nystagmus (HGN) test. It’s an eye test, and if you fail, you’ll probably end up in police custody.
Understand how an HGN test works in case of a DUI stop
Every person has a maximum peripheral vantage point, often referred to as “deviation from center.” This is the farthest point from looking straight ahead that you glance to the side without moving your head. Nystagmus is an involuntary jerking or erratic movement of the eyeball that naturally occurs when one reaches the maximum peripheral vantage point.
If you have had too much to drink, your eyeballs may show a pronounced jerking movement, which may start occurring even before reaching maximum deviation from center. When a police officer administers an HGN test, you will have to track the movement of an object (often the officer’s index finger or an ink pen) from left to right or up and down using only your eyes (not your head). The officer administering the test will closely observe your eyes as you perform the test. If he or she determines pronounced nystagmus, it constitutes probable cause for a DUI arrest.
Know your rights
You are not obligated to take an HGN or any other field sobriety test when a Pennsylvania police officer asks you to do so during a DUI stop. Refusing a preliminary alcohol screening test is not cause for arrest. Bear in mind, however, that refusing a sobriety test does not guarantee that an arrest will not take place. The officer may establish probable cause some other way.
Whether you take an HGN test or not, if a Pennsylvania deputy places you under arrest for suspected DUI, you will want to seek legal support right away. Experienced guidance is often the key factor to obtaining a positive outcome in court.