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. Experienced field sobriety tests lawyer at The Law Offices of J. Scott Smith, PLLC can provide the necessary legal assistance in these situations. These tests may help establish if the driver has a .08 BAC (blood alcohol concentration) or higher.
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. A skilled DWI Lawyer can help you understand and challenge these tests in court. In putting together these testing standards the following was observed:
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 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:
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:
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:
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:
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 or OLS is a timed test. The officer is looking for a total of four clues:
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:
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.