Reader’s Question:

I don’t really understand how horizontal gaze nystagmus test can be an indication that a person had been drinking. What are the clues that officers in Tuscaloosa, Alabama look for when they conduct this test in a DUI suspect?

Dallin

Tuscaloosa, AL

Horizontal gaze nystagmus (HGN) is one of the standardized field sobriety tests (SFST’s) that police officers, including those in Tuscaloosa, Alabama, conduct during a DUI investigation. During the HGN test, the police officer holds a penlight about 12-15 inches in front of the DUI suspect’s eyes and asks him/her to follow the pen with the eyes without moving the head. Officers always start with the left eye and they look for three specific clues.

The first one would be the lack of smooth pursuit in which the officer would take note whether the eyes move smoothly or jerks when they move from side to side. There is actually a standardized pace the officer needs to have the eyes move side to side. The second clue would be the distinct nystagmus at maximum deviation in which the officer would take note if there is a distinct jerking of the eye when it moves as far to the side as possible and is kept in that position for several seconds. The last clue would be the onset of nystagmus prior to 45 degrees in which the officer observes if the eye starts to jerk before it reaches a 45-degree angle as it moves towards the side.

Tags: DUI, DUI lawyer, field sobriety tests