Police and prosecutors have several ways to prove that a person was impaired by alcohol in driving while intoxicated (DWI) cases. New Jersey law requires any driver to cooperate with some of these methods, such as breath testing. Other methods are not mandatory, but refusal to cooperate could work for you or against you if your case goes to court. Field sobriety tests (FSTs) provide police with circumstantial evidence that you were under the influence of alcohol or another substance at the time they pulled you over. Nothing in state law requires you to perform FSTs when asked by a police officer. The reliability of FSTs is questionable at best, so if you agree to perform them, an experienced DWI defense attorney can help defend you against whatever prosecutors claim the tests established.
What Are Field Sobriety Tests?
FSTs are a series of physical tests administered by police officers when they suspect that a person is under the influence of alcohol or drugs. Police will often ask a person to perform FSTs when they suspect DWI but are not certain that they have enough probable cause for an arrest. Flawless performance on FSTs is unlikely to result in police deciding not to arrest you, because a police officer has usually already made up their mind about an arrest when they ask you to perform FSTs.
The National Highway Transportation Safety Administration (NHTSA) has approved three standardized FSTs, which are commonly accepted by New Jersey courts:
1. Horizontal gaze nystagmus (HGN): An officer asks the person to look at a stimulus, which could be their finger, a pen, or another object, and to follow it with their eyes without moving their head. The officer is looking for involuntary eye movements, known as nystagmus, which are supposedly a sign of intoxication.
2. Walk-and-turn: The officer instructs the person to walk a straight line, heel-to-toe, for nine steps, and then to turn around and take nine more heel-to-toe steps back to where they started.
3. One-leg stand: The person must stand with one foot raised about six inches off the ground, counting out loud, until the officer tells them to stop.