Evaluation Factors Flashcards

During the Walk-and-Turn, a suspect takes 17 steps on the first leg instead of the required 9. How should the officer score this?

Answer: Score 'incorrect number of steps' as one clue

Taking an incorrect number of steps (more or fewer than instructed) counts as a single scored clue on the Walk-and-Turn.

What is the maximum recommended speed for moving the stimulus during the smooth pursuit phase of HGN?

Answer: Two seconds from center to side (one full cycle in approximately four seconds)

NHTSA recommends moving the stimulus at approximately two seconds from center to the side, completing a full pass in about four seconds.

Which SFST clue specifically addresses the suspect's behavior during the instruction phase of the Walk-and-Turn?

Answer: Cannot keep balance while listening

'Cannot keep balance while listening' is scored during the instruction stance phase before the suspect begins walking.

A suspect tells the officer they have an inner ear condition before SFSTs begin. The officer should:

Answer: Document the condition and consider its potential effect on balance test results

Known medical conditions affecting balance or vision must be documented and considered when interpreting SFST results.

In SFST scoring, when a suspect performs the Walk-and-Turn pivot turn by spinning on one foot instead of a series of small steps, this is scored as:

Answer: Turns improperly

Failing to execute the turn as demonstrated — taking a series of small steps around rather than spinning — is scored as 'turns improperly.'

Which factor about lighting is most important when administering the HGN test at night?

Answer: The stimulus must be clearly visible to the suspect's eyes without shining a light directly into them

Adequate lighting ensures the officer can observe the eye movement clearly, but direct light in the suspect's eyes can cause pupil constriction and interfere with the evaluation.

What is the purpose of the 'instruction phase' observation period in both the Walk-and-Turn and One-Leg Stand tests?

Answer: It provides an opportunity to score balance and attention clues before physical performance begins

During the instruction phase, the suspect must maintain a specific stance, and any inability to do so (losing balance, starting early) is itself a scored clue.