Police's first act
I was present at a domestic disturbance call once.
The first officer arriving on scene ordered/asked me to remove my hands from my jacket pockets. (Alaska, wintertime, outside) I complied, though I was not sure why he wanted that at the time (in retrospect, it is obvious).
After he determined that I was not involved, but only a witness, he looked back at me, observed my hands and said, "Put your hands back in your pockets." and smiled at me.