What is the total maximum number of clues observed in the HGN exercise?

In the Horizontal Gaze Nystagmus (HGN) exercise, the total maximum number of clues that can be observed during testing is six. This exercise is one of the standardized field sobriety tests used by law enforcement to assess potential impairment due to alcohol or drugs.

Each eye is evaluated for three distinct indicators, or clues, of nystagmus, which is an involuntary jerking of the eyes. The specific clues noted during the HGN test include:

1. Lack of smooth pursuit in either eye.

2. Distinct and sustained nystagmus at maximum deviation for either eye.

3. Onset of nystagmus prior to a 45-degree angle for either eye.

Since two eyes are assessed, with three clues identified per eye, this results in a total of six clues that can be evaluated during the HGN exercise. Understanding these clues is critical for law enforcement officers as they gather evidence of a driver’s impairment during a traffic stop.