It is true sometimes it is really hard to prove Zimmerman was not self defense. Zimmerman is in a unmatched advantageous situation compared with Martin. He smartly took advantage of the Florida law. Martin was just stupid and paid his life, he didn't know Zimmerman was "prepared to kill with justification" and "ready to pull trigger". Martin was not an opponent of Zimmerman. Martin was a bad teen and Zimmerman is an evil.