Standardized Field Sobriety Tests

The first time most people realize that they are under investigation for DUI in Greenville, South Carolina, is when they are asked to perform a series of tasks called the Standardized Field Sobriety Tests (SFST) or a Breathalyzer.

The field sobriety test was determined by the National Highway Traffic Safety Administration (based on studies that they financed) to discern whether a driver’s Blood Alcohol Content was above a .08. The three tasks are the Horizontal Gaze Nystagmus field sobriety test, the Walk and Turn field sobriety test, and the One-Leg Stand field sobriety test.

Below, Attorney at Law John Bateman has given examples of what a field sobriety test can entail for a DUI in Greenville, South Carolina.

Table of Contents

Horizontal Gaze Nystagmus A.K.A. The “Pen Test” 

Nystagmus is the medical term for the involuntary jerking of the eyes. In this field sobriety test, the officer holds a stimulus (it may be a pen, a light, or just the officer’s finger) 12 to 15 inches from the driver’s eyes and instructs the driver to follow the stimulus with his eyes.

The officer then performs a routine to check for a number of “clues” that the driver is impaired. The problem with the HGN, however, is that it depends on the officer adhering to a strict protocol in order for it to be (even arguably) accurate. Not every DUI is the same.

Moreover, nystagmus can be caused by a wide variety of medical conditions which the officer has no ability diagnose.

Despite the correlation between alcohol consumption and HGN, some trial courts across the country still do not admit the results of the HGN test into evidence for DUI arrests. Evidence prosecutors have presented to courts has at times been insufficient to satisfy the courts’ evidentiary standards for admitting scientific or technical evidence.

As a result, law enforcement officers in a number of jurisdictions use the HGN test only for purposes of establishing probable cause if at all, without securing admission of the test results into evidence at trial.

DUI Field Sobriety Tests

Walk and Turn Field Sobriety Test

The officer instructs the driver to stand heel-to-toe and take 9 heel-to-toe steps down a real or imaginary line, while counting each step outloud. The driver is then to turn by taking a series of small steps, and take 9 heel-to-toe steps back, in the same fashion.

Just like with the HGN test, the officer must adhere to a strict protocol to ensure even arguable accuracy. Officers are regular people, and just like with all of us, they sometimes make mistakes in administering these tasks. Furthermore, the Walk and Turn essentially tests the driver on a difficult balance task that they have likely never performed.

For this reason, many practitioners agree that this test is failure-designed. For example, according to training guidelines published by National Highway Traffic Safety Administration (NHTSA), if a driver lifts his arms above 6 inches from his sides for balance once and places his heel a fraction more than a 1/2 ahead of his toe on one step then that driver is impaired.

One Leg Stand Field Sobriety Test

The officer instructs the driver to stand on one leg, with the other foot 6 inches off the ground and parallel to the ground. The driver is then to stare at the raised foot and begin counting aloud until the officer stops him. Just as in the Walk and Turn, the driver is not allowed to use his arms for balance.

According to NHTSA, by simply raising one arm away from their body and swaying a little, the driver has indicated that they are intoxicated. Most people can agree that this is ridiculous.

What’s Next After the Field Sobriety Test?

The driver, nervous and tired, has been forced to perform the field sobriety test which amount to 1 medical diagnosis by an unlicensed physician and 2 balance tricks. Unsurprisingly, the driver has not performed to NHTSA standards. Next comes arrest and a ride to the law enforcement center in the back of a patrol car.

This field sobriety test is routinely conducted for a DUI in Greenville, South Carolina. John Bateman is here to help you navigate through all the complex and overwhelming information for DUI arrests. Please contact John Bateman, Attorney at Law, today! Call 844.DUI.ALLY.

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