You made it up.
I could just as easily say that Martin was being stalked by a stranger in a car while on the way home (true). He ran away and lost the guy (true). After a minute he started home again only to be confronted by the guy who was now looking for him on foot and who had a gun.
The stalking stranger with the gun accosted him. Martin defended himself and over-powered the stranger with the gun who had followed and stalked him.
The bottom line is that the police see no reason to arrest Zimmerman.
Show me where that’s in the reports.