SFST HGN Test 2

Question 1

During HGN testing, at what angle from center should the officer begin checking for Lack of Smooth Pursuit?

Accepted Answer

20 degrees

Answer

The officer begins moving the stimulus from center and checks for Lack of Smooth Pursuit as the eye tracks through the full range of motion.

Question 2

Which medical condition can produce HGN clues that may be mistaken for alcohol impairment?

Accepted Answer

Inner ear disorder (labyrinthitis)

Answer

Inner ear disorders such as labyrinthitis can cause nystagmus that mimics alcohol-induced HGN, which officers must consider.

Question 3

In the HGN test, how many total clues is the officer looking for across both eyes?

Accepted Answer

6

Answer

Officers check for three clues in each eye (Lack of Smooth Pursuit, Distinct Nystagmus at Maximum Deviation, and Onset of Nystagmus Prior to 45 Degrees), totaling six clues.

Question 4

What does 'Distinct and Sustained Nystagmus at Maximum Deviation' mean in the HGN test?

Accepted Answer

The eye jerks clearly and continuously when held at the far edge of gaze

Answer

At maximum deviation, the eye is held for at least four seconds and a clue is recorded if clear, sustained jerking is observed.

Question 5

A subject's eye onset of nystagmus is observed at 40 degrees. How should this clue be scored?

Accepted Answer

A clue because onset occurred before 45 degrees

Answer

Onset of nystagmus prior to 45 degrees is a clue; 40 degrees is less than 45, so this eye earns that clue.

(SFST) Standardized Field Sobriety Testing Certified Practice Test

(SFST) Standardized Field Sobriety Testing Certified Practice Test

SFST HGN Test 2