When law enforcement makes a traffic stop and suspects you of drunk driving, the officer may ask you to perform one or several field sobriety tests (FSTs). These tests are used by the police to determine whether or not a person is intoxicated.
The three standardized FSTs approved by the NHTSA include:
- The horizontal gaze nystagmus (HGN) test – The officer holds a pen, flashlight, or another object about a foot away from the suspect’s face and watches the suspect’s eyes follow the object. If the suspect’s eyes jerk around or twitch, it is a sign of intoxication.
- The walk-and-turn test – The suspect must walk a straight line—heal-to-toe—in nine steps, then turn back to take another nine steps.
- The one-leg stand test – The suspect must raise one leg approximately six inches above the ground and count numbers without showing any signs of poor balance.
However, FSTs are subjective in nature. Even if you believe you passed the tests and followed all instructions, the police can use your results against you to establish probable cause and make an arrest. The truth is that no matter what drills you perform, you cannot pass them.
Additionally, officers may not consider the suspect’s health conditions (e.g. back problems, knee problems, foot problems, etc.), road conditions (e.g. uneven and elevated surfaces), and weather conditions (e.g. rain and wind).
If an officer asks you to perform an FST, you are legally allowed to say “no.” Unlike a post-arrest chemical test, you cannot be prosecuted for refusing a field sobriety test.
Keep in mind, you could still be arrested if you refuse. The good news is that law enforcement won’t have the FSTs results to use against you.