Well he was under a doctor's supervision for the medication he was taking, was going to school to improve himself, was employed, was paying his bills, had a valid concealed carry permit after a background check, was happily married to a wife trying to get her degree to become a nurse, had helped to set up the Neighborhood Watch Program, and lived and paid rent in the RTL complex and thus had a right to be on its walkways and call in suspicious persons to the police.
Instead of trying to vilify the innocent child
You mean a troubled teen who had missed 58 days of school and been suspended for vandalism and possession of someone else's jewelry and burglary equipment, with substantial marijuana in his system, into mixed martial arts, and who the prosecutor admits was on top of Zimmerman with his hands over his mouth trying to keep him from screaming out for help, as the prosecution has already admitted in court and on the record.
You do understand that if TM had stopped his assault at that time, that both would be alive -- TM probably doing time -- but still alive and well. He had won. He could claim to his bros that he was the man. He could have withdrawn at that point and run back home. But that wasn't enough for him. He had to finish off his opponent. That was his choice and his final mistake.
Zimmerman had already taken a severe beating before using the gun and some of the testimony indicates that Martin had seen the gun and it was just a question of who got to it and used it on the other guy first. George Zimmerman probably saved other lives as well as his own in the incident i.e. he basically did the world a favor.