Reader’s Question:

I was lucky my DUI case here in Tulsa, Oklahoma was dismissed and when I was arrested, I got more interested in the horizontal gaze nystagmus test when the officer did the test to me. What are the clues that the police officers are looking for when they conduct this test?

Ramona

Tulsa, OK

The horizontal gaze nystagmus (HGN) test is one of the standardized field sobriety tests that is recognized by the National Highway Traffic Safety Administration (NHTSA). The procedure to be used by police officers is set out by the NHTSA in the DWI Detection and Standardized Field Sobriety Testing Student Manual. Prior to administering the HGN, the eyes are checked for equal pupil size and equal tracking ability. Medical disorders or injuries are likely the cause of the nystagmus if the eyes don’t track together or if the pupils are unequal in size.

When the police officer conducted the HGN test on you when you were arrested for DUI in Tulsa, Oklahoma, the NHTSA standardized clues that the officer was looking for were onset of nystagmus prior to reaching a 45-degree angle, lack of smooth pursuit and distinct nystagmus at maximum deviation. Standardized administration procedures include keeping the tip of the stimulus slightly above the suspect’s eyes, holding the stimulus 12-15 inches in front of the suspect’s nose, always moving the stimulus smoothly, always checking for all three clues in both eyes, starting with suspect’s left eye, checking the clues in sequence and always checking for clues at least twice in each eye.

Tags: DUI, DUI lawyer, field sobriety tests