shortly after Mr. Zimmerman got out of his truck Trayvon ran off into the darkness So? It wasn't Mr. Neighborhood Watch's responsibility to go after him, as the dispatcher made known to him. In this country, we are supposed to be able to run off if we choose, unless guilty of a crime-- and this kid wasn't. (I would certainly run away if I were minding my own business and some guy was following me in a vehicle, and I'm an adult. That's what we advise our children to do when they feel themselves in danger from a stranger.)
Zimmerman made bad choices that resulted in someone's death.
Mr. Zimmerman did not go after him when Trayvon fled into the darkness. Mr. Zimmerman headed back to his truck but did not make it because Trayvon turned around and jumped him. Mr. Zimmerman was on his back with Trayvon on his chest beating in his face. Witnesses saw this happen and told that to police.
If you were ambushed in the dark and had some thug on top of you beating in your face what would you do? Start sing “Kum Bay Ya”?