Pharisees

What was it that Jesus wrote on the ground when the gang of scribes and Pharisees brought the woman to Him and told Him that because she had been caught in the act of adultery, the law of Moses commanded that she be stoned to death?  How long was He writing before the eldest man in the group walked away?  Did He intentionally knock out the eldest man first because he was the leader of the group?  Did He write new information after each man left?  Those are some of the questions that came to mind when I listened to the Gospel reading last Sunday (the fifth Sunday of Lent).  The relevant part of the Gospel is as follows: