If Martin was casing houses to potentially rob, I don’t think he’d be doing that in the gated community that his father lived in.
That is an unfounded speculation. So let me indulge myself in one of my own.
If Trayvon Martin had just been walking along straight back to the home he was living in I don't think George Zimmerman would have been suspicious and called the police.
Maybe Martin was out to score some weed. Maybe that’s what upset him about Zimmerman following him.