When a police officer pulls you over and thinks you’ve had too much to drink, they usually don’t just arrest you right away. Instead, they need to gather evidence that supports their allegations.
They may ask you questions while you are still in your vehicle and then ask you to exit it for a few field sobriety tests. You generally don’t have the right to decline such testing without risking an arrest. What tests will an officer perform to try to establish your level of chemical impairment?
The walk-and-turn test
An officer will likely ask you to walk by placing your heel in front of the toe of the other foot for a specific number of steps or a specific distance. You will then have to turn and walk back along the same straight line.
If you stumble, take too many steps or can’t walk in a straight line, the officer will likely use that as grounds to request a breath test.
The one-leg stand test
Excessive alcohol can impair your sense of balance and your motor function. Having you stand on one leg with the other foot a little bit off the ground can be a challenge on its own. Officers typically combine the balance challenge with a requirement to count backward or even recite the alphabet backward in some cases. If you put your foot down, lose your balance or make a mistake while counting backward, that could easily lead to your arrest.
The horizontal gaze nystagmus
When you move your eyes from side to side, they make small involuntary moves or jerks, which professionals call the horizontal gaze nystagmus (HGN). That movement becomes more obvious when you have had alcohol.
The HGN test looks for an exaggerated jerking reflex when you move your eyes from side to side. Unlike the other two tests, which people can sometimes practice for while drinking to improve their motor skills and balance while under the influence, there is no way for a driver to prepare for or practice the HGN test.
Understanding field sobriety tests can help you understand why you failed them and make it easier for you to defend against a pending operating while under the influence (OUI) charge.