DUI Field Sobriety Tests: The Finger Count Test

The DUI Finger Count FST has been used by experienced officers to assist them in DUI Investigations for several years and was among one of the six primary FSTs studies by SCRI during the 1977 scientific research of FSTs. The Finger Count FST is also recommended by HITSA as an additional test to assist an officer with a DUI Investigation. Many of the same necessary exercises used to drive a vehicle are tested with the Finger Count FST. Tasks such as:

a. Information processing.
b. Short-term memory.
c. Judgment and decision making.
d. Steady sure reactions.
e. Clear vision.
f. Small muscle control.
g. Coordination of limbs.

The DUI Finger Count FST requires a subject to put one hand in front of him/her with the extended palm facing upward. The top of the thumb is then touched with the tip of the index, middle, ring and little finger. After each touch, the finger and thumb are separated. The DUI suspect is required to count out loud, "ONE, TWO, THREE, FOUR" in relation to each finger-thumb connection. The process is then reversed. Three (3) complete sets are performed.

Administration of the Finger Count FST

Start by instructing the DUI suspect to stand with his/her feet together and arms to his/her sides. Instruct the DUI suspect not to begin until told to do so.

      1. When told to do so, instruct the DUI suspect to extend one hand directly in front of him/her. Open the hand with the palm facing upward. The thumb is then touched with the index finger and the subject shall count out loud, "ONE." The thumb is then touched with the middle finger and the subject shall count out loud, "TWO." The thumb is then touched with the ring finger and the subject shall count out loud, "THREE." The thumb is then touched with the little finger and the subject shall count out loud, "FOUR."

      2. The process is then reversed. The thumb is touched with the little finger and the subject shall count out loud, "FOUR." The thumb is touched with the ring finger and the subject shall count out loud, "THREE." The thumb is then touched with the middle finger and the subject shall count out loud, "TWO." The thumb is then touched with the index finger and the subject shall count out loud, "ONE."

      3. The subject is then instructed to perform three (3) complete sets. Ensure that the subject understands the FST instructions.

Interpretation of the Finger Count DUI Test

The major clues associated with the Finger Count FST are:

1. The subject's ability to follow instructions.
2. The subject starts too soon.
3. The subject does not count as instructed.
4. The subject does not touch fingers as instructed.
5. The subject does not perform the correct number of sets.
6. The subject stops before instructed to do so.