"Then I heard him fall, then the phone hung up. I called back and (not legible) no response. In my mind I thought it was just a fight. Then I found out this tragic story."
Zimmerman recently waived his right to a pretrial hearing under Florida's "stand your ground" law, which allows people to use deadly force when threatened regardless of where they are.
His attorneys will claim self-defense at trial.
A representative of the special prosecutor handling the case did not immediately return an e-mail message seeking comment on the evidence.
Prosecutors renewed their motion for a gag order in the case Thursday because, they say, they're concerned about finding an impartial jury given the "inordinate amount of media coverage."
Two previous gag order requests by the prosecution have been denied.