The police have the right to pull over a vehicle when there is reasonable suspicion that a driver is performing, will perform or has performed a criminal activity. For example, a vehicle that is swerving between lanes, speeding or running red lights may be operated by a drunk driver. To gather further evidence, the police can ask the driver questions and perform tests.
It’s common for police to ask drivers to do breath tests. A breath test is a small device that police carry around to examine the blood alcohol content of drivers. If a driver’s blood alcohol content is above the legal limit, then the driver could face criminal charges.
However, the police could also ask drivers to do field sobriety tests. Field sobriety tests are a kind of physical examination sanctioned by the National Highway Traffic Safety Administration. There are three kinds of standardized field sobriety tests:
Horizontal gaze nystagmus test
The driver may be asked to focus on a pen, finger or flashlight. The officer will move the object and the driver must keep their eyes on it without moving their head. If the driver’s eyes flicker too much, it could indicate inebriation.
Walk-and-turn test
The driver may be asked to walk on a straight line. The driver may then walk several paces out and walk back. If they stumble, walk off the line or walk too many steps, the police could suspect the driver is drunk.
One-legged stand test
The driver may have to lift one leg up while staying balanced on the other. The driver may have to do this for several seconds without falling or using their hands for balance. Failing this could cause an officer to believe the driver is drunk.
Despite their common use, field sobriety tests are deeply subjective and highly flawed. Drivers may need to learn about their legal defense options if they’re suspected of drunk driving and a field sobriety test is part of the evidence.