Field Sobriety Tests in DUI Cases: The Hand Pat Test

Although the DUI Hand Pat FST has not been tested under scientific conditions, experienced officers have indicated that it is a reliable FST. The DUI Hand Pat Test requires the subject to divide his/her attention between simple mental and physical tasks. Many of the same necessary exercises used to drive a vehicle are tested with the Hand Pat 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 Hand Pat FST requires a subject to place one hand extended, palm up, out in front of him/her. The other hand is placed on top of the first, with the palm facing down. The top hand then begins to pat the bottom hand. The top hand rotates 180 degrees alternating between the back of the hand and the palm of the hand. The bottom hand remains stationary. The DUI suspect counts out loud, "ONE, TWO, ONE, TWO, ONE, TWO, etc." in relation with each pat.

Administration of the DUI Hand Pat Test

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 subject to put one hand out in front of him/her with the open palm facing upward. The opposite hand is then placed on top of the first hand with the open palm facing downward.

      2. The hand with the palm facing upward is held in a stationary position. The hand on top with the palm facing downward will be the only hand moving.

      3. When told to begin, the subject will rotate the top hand 180 degrees and pat the back of the top hand to the palm of the bottom hand simultaneously counting out loud, "ONE." The top hand then rotates 180 degrees so the palm of the top hands pats the palm of the bottom hand simultaneously counting out loud, "TWO." The process then repeats. The subject should start at a slow speed then gradually increase the speed until a relatively rapid pace is reached.

      4. The subject should perform this FST for a minimum of 10 seconds but no more than 15 seconds.

Interpretation of the Hand Pat Test

The major clues associated with the Hand Pat FST are:

1. The subject's ability to follow instructions.
2. Starts too soon.
3. The subject does not count as instructed.
4. The subject does not pat his/her hands as instructed.
5. Stops before instructed to do so.