Types of field sobriety tests

On Behalf of | Jan 18, 2022 | Criminal Defense, DUI |

If an officer in Birmingham, Alabama, suspects a person of drunk driving, they may pull the driver over to check for intoxication. State laws allow officers to check for impairment using field sobriety tests, which require the driver to perform physical tasks.

Types of field sobriety tests

The horizontal nystagmus test checks nystagmus, or involuntary eye jerking, by having the driver follow an object such as a flashlight. The officer examines each eye separately for three clues, including smooth transitions, maximum deviation of distinct jerking and a 45-degree nystagmus.

The walk-and-turn test helps the officer check a driver’s divided attention, balance and ability to follow directions. The officer instructs the driver to walk nine steps in a straight line, heel to toe, and change directions. The officer will watch for certain cues, such as drivers starting before they are told and not taking the correct number of steps.

The one-leg stand test requires the driver to lift one leg six inches off the ground and balance for several seconds. The officer watches to determine if the driver hops, uses an arm for balance, sways or puts the foot down too early.

Accuracy of field sobriety tests

There have been ongoing debates about the accuracy of standard field tests and the reliability for a DUI charge. For example, musculoskeletal conditions, hearing issues and previous injuries may make the test more difficult for sober drivers.

A criminal defense strategy could challenge the tests if an officer failed to ask the defendant about medical conditions or contact lenses. An officer should consider if the driver is wearing high heels or other clothing that may skew results. The National Highway Traffic Safety Administration requires the test surface to be even terrain free from snow, ice and rocks.

A driver can commonly refuse to take field sobriety tests without penalty, but they can also challenge the results. For example, if the officer uses nonstandard tests, such as counting backwards, the court may dismiss that evidence. Pointing out improper officer behavior might be enough to get criminal charges reduced or dismissed.