Types of Field Sobriety Tests in Prince William County DUI Cases 

Types of field sobriety tests in Prince William County DUI cases include tests standardized by the NHSTA. The field sobriety tests that are standardized by NHTSA include the HGN, horizontal gaze nystagmus, walk and turn, and stand on one leg, and they are usually administered in that order. A skilled DUI attorney can help you understand these tests in detail.

Horizontal Gaze Nystagmus

With the horizontal gaze nystagmus test, an officer either uses a pen or a small light and they hold it in front of the driver’s eyes, making them follow the pen with their eyes but without turning their head.

Issues with Horizontal Gaze Nystagmus

During this test, the officer is checking for the driver’s gaze nystagmus, or the twitching of the eyeballs when the eye catches certain degree angles. When the eye is at a certain angle, it will twitch or it is more likely to twitch. According to the NHTSA, an eye will twitch 70% of the time when somebody has a BAC of 0.10 or more. However, the horizontal gaze nystagmus test is specific. An officer must hold the pen at the exact angle to administer these types of field sobriety tests in Prince William County DUI cases. This can especially cause problems if the driver is taller than the officer. For this reason, anyone’s nystagmus test results should be examined by a professional defense attorney before considering a guilty plea.

Walk-and-Turn Test

Among other types of field sobriety tests in Prince William County DUI cases is the walk-and-turn test. The walk-and-turn test is where an individual needs to take nine steps forward, make a small step turn, and then nine steps back. Now, all of the driver’s steps need to be heel to toe with their hands at their side, and they must count these steps out loud. The individual cannot stumble or sway and must look down at their feet the entire time.

Issues with Walk-and-Turn

There are certain ways that tests have to be administered and explained that are not always carried out correctly. In addition, the surface the driver is standing on can influence the test if there is an incline or gravel present. If there is no line for the individual to follow and it is dark outside, they may not be able to tell if they are going straight or not. If the test is administered at the side of the highway, cars may be flashing lights and distracting the driver. The types of shoes one wears can also affect this test.

One-Legged Stand

Other types of field sobriety tests in Prince William County DUI cases include the one-legged stand test. During this test, a driver must stand on one leg and then lift their other leg up six inches above the ground with their foot parallel to the ground. While they stare at their foot with their hands at their side, they must count until the officer tells them to stop. To pass this test, the individual cannot sway, hop, put their foot down, or lift their arm. The driver must look at their foot the whole time while counting.

Issues with One-Legged Test

The one-legged test is probably one of the least accurate methods of sobriety testing. The NHSTA states that the accuracy level of this test only remains around 60% if the driver is made to count to twenty seconds. If the test is made to last longer than 20 seconds, the accuracy drops greatly because many individuals who are not well-coordinated will be unable to complete it beyond a certain time limit.

Challenging a Field Sobriety Test

There are many elements that can adversely impact the types of field sobriety tests in Prince William County DUI cases. If a driver has a skilled defense attorney on their side, they should be able to look into the administration of the tests and compare their results to the NHTSA standards. If you wish to learn more about the different types of field sobriety tests in Prince William County DUI cases, do not hesitate to reach out to a qualified traffic lawyer today.