SFST Observation Skills 2 — Questions and Answers
Question 1: During the VGN (Vertical Gaze Nystagmus) check, an officer observes nystagmus at maximum elevation. What does this indicate?
- The suspect is definitely under the influence of alcohol
- It may indicate high doses of depressants, inhalants, or PCP (Correct answer)
- It is a normal physiological response with no significance
- The officer should immediately arrest the suspect
Correct answer: It may indicate high doses of depressants, inhalants, or PCP
Vertical Gaze Nystagmus is associated with high doses of CNS depressants, inhalants, or PCP, not typically alcohol alone.
Question 2: When observing a suspect's eyes during the HGN test, the officer should hold the stimulus approximately how far from the suspect's nose?
- 6–8 inches
- 12–15 inches (Correct answer)
- 18–24 inches
- 3–4 inches
Correct answer: 12–15 inches
The stimulus should be held 12–15 inches from the suspect's nose and slightly above eye level for proper HGN administration.
Question 3: An officer notices a suspect has resting nystagmus before the HGN test begins. What should the officer do?
- Proceed with the test and record the resting nystagmus as a clue
- Discontinue the HGN test and note the observation in the report (Correct answer)
- Assume the suspect is sober because resting nystagmus is alcohol-related
- Ignore it and score only the standard six clues
Correct answer: Discontinue the HGN test and note the observation in the report
Resting nystagmus can indicate very high BAC or other medical conditions, and the officer should note it and consider not administering the full test.
Question 4: During the Walk-and-Turn test, the officer observes the suspect take 9 steps on the way out instead of the required 9 steps. What is the correct scoring?
- Score as a clue for improper turn
- Score as a clue for wrong number of steps
- This is not a scorable clue under NHTSA guidelines (Correct answer)
- Score as a clue for stepping off the line
Correct answer: This is not a scorable clue under NHTSA guidelines
Taking the correct number of steps (9) on the way out is not a clue — only taking more or fewer than instructed counts.
Question 5: In the One-Leg Stand test, what is the maximum time the officer should observe the suspect before stopping the test?
- 20 seconds
- 25 seconds
- 30 seconds (Correct answer)
- 45 seconds
Correct answer: 30 seconds
The One-Leg Stand test is timed for 30 seconds; the officer counts aloud and stops the test at that point.
Question 6: A suspect completes the Walk-and-Turn test but raises their arms more than 6 inches above their sides on the return trip. How many clues does this represent?
- Zero — arm raising is only scored once per test
- One clue for raising arms (Correct answer)
- Two clues — one for each direction
- One clue per step where arms were raised
Correct answer: One clue for raising arms
Raising arms is scored as one clue regardless of how many times it occurs during the test.
Question 7: When observing the suspect's initial position during the Walk-and-Turn test instruction phase, the officer notes the suspect cannot maintain the heel-to-toe stance. This is considered:
- A clue scored immediately
- Only a clue if the suspect falls out of position more than three times
- Cannot maintain balance during instructions — one of the eight scored clues (Correct answer)
- Not a clue — the test has not yet begun
Correct answer: Cannot maintain balance during instructions — one of the eight scored clues
Cannot maintain balance during instructions is one of the eight standardized clues for the Walk-and-Turn test.
SFST Observation Skills 2
During the VGN (Vertical Gaze Nystagmus) check, an officer observes nystagmus at maximum elevation.
What does this indicate?