Winston-Salem Field Sobriety Test Lawyer

Winston-Salem Field Sobriety Test Attorney

These tests were developed by the NHTSA to be administered in a standardized manner to obtain indicators of impairment and establish probable cause for arrest. These tests may help establish if the driver has a .08 BAC (blood alcohol concentration) or higher.

The Three Standardized Roadside DWI Tests In Winston-Salem, NC

The National Highway Traffic Safety Administration (NHTSA) along with the Southern California Research Institute in 1981, and again in 1998, established this set of roadside tests to help law enforcement determine if a motor vehicle driver was impaired. In putting together these testing standards the following was observed:

  • The Horizontal Gaze Nystagmus test (HGN) – If the officer observed four or more clues in the driver, 88% of the time the driver was a .08 BAC or higher
  • The Walk-and-Turn test (WAT) – If the officer observed two or more clues in the driver, 79% of the time the driver was a .08 BAC or higher
  • One-Leg Stand test (OLS) – If the officer observed two or more clues in the driver, 83% of the time the driver was a .08 BAC or higher.

By administering all three tests combined, based on these standards, there was a 91% accuracy rate in finding that the driver was impaired and was over the legal BAC limit.

Below you will find a full breakdown of each of the standardized tests and what the officers are checking for.

The Horizontal Gaze Nystagmus Test (HGN)

The officer is looking for a total of six clues, or three in each eye, when administering the Horizontal Gaze Nystagmus test or HGN test. The officer will first check for equal size and tracking, and then he checks for lack of smooth pursuit, distinct nystagmus at maximum deviation, and onset of nystagmus prior to 45 degrees. Here’s how the test is supposed to be done:

  • Remove eyeglasses
  • Check pupils for equal size
  • Check eyes to ensure they both track stimulus equally
  • Begin with the left eye
  • Check each eye independently
  • Hold stimulus 12-15 inches in front of the nose
  • Check for a lack of smooth pursuit (center to side in 2 seconds)
  • Check both eyes twice to confirm observations
  • Check for distinct nystagmus at maximum deviation (hold at maximum deviation for a minimum of 4 seconds each time, nystagmus must be distinct and sustained)
  • Check both eyes twice to confirm observations

Part of the HGN test is the Vertical Gaze Nystagmus test or VGN. This test is done last. NHTSA has said “Vertical nystagmus was not examined in the original research that led to the validation of the SFST battery.”

The Vertical Gaze Nystagmus should be administered as follows:

  • Position stimulus 12-15 inches from nose
  • Raise stimulus until the subject’s eyes are elevated as far as possible
  • Hold for approximately 4 seconds

The Walk-And-Turn Test (WAT)

As the name implies, the Walk-and-Turn test or WAT is a walking test. The police look for a total of 8 clues in this test:

  • Can’t balance during instructions
  • Starts too soon
  • Stops
  • Misses heel to toe by 1/2 inch or more
  • Steps off the line
  • Uses arms for balance
  • Turns incorrectly
  • Wrong number of steps

While the NHTSA has said these tests are not pass/fail tests, if the officer observes two or more clues on the WAT the officer will conclude that you did not perform the test to his or her satisfaction.

The test is usually administered as follows:

  • Instruction stage: left foot on the line, right foot directly in front of left foot with heel touching toe.
  • Do not move from this position until told to do so.
  • Do you understand?
  • Walking stage – When told to begin, take nine steps heel touching toe, when you reach your ninth step, leave your lead foot on the line and turn making a series of small steps, and then return nine steps heel to toe. While you are doing this, keep your hands at your side, watch your feet at all times, count out loud, and don’t stop until you’ve completed the test.
  • Do you understand these directions?

The NHTSA has stated, “The original research indicated that individuals over 65 years of age, back, leg or inner ear problems had difficulty performing this test. Individuals wearing heels more than two inches high should be given the opportunity to remove their shoes.”

The One-Leg Stand Test (OLS)

The One-Leg Stand test or OLS is a timed test. The officer is looking for a total of four clues:

  • Sway
  • Arms to balance
  • Hops
  • Puts foot down

Again the police observe two or more clues in this test you will not have completed it to his or her satisfaction. The test is administered as follows:

  • Instruction stage – Stand with feet together and arms at side, don’t move from this position until told to do so.
  • Do you understand?
  • Raise either foot of your choice approximately six inches off the ground keeping foot pointed.
  • Keep both legs straight.
  • Look at your elevated foot.
  • Count out loud: one thousand one, one thousand two, and so on until told to stop.
  • Officer must time for 30 seconds.

Our Winston-Salem Field Sobriety Test Lawyers are Ready To Help!

You need a lawyer that understands this battery of standardized tests. Our DWI lawyers have successfully completed the NHTSA Standardized Field Sobriety Tests 24-hour course, the same training the police officers receive. Contact The Law Offices of J. Scott Smith, PLLC, for your free DWI consultation by calling 336-992-3600 today. You can also reach the firm using the online contact form.

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