I just don't think we have the full story. That's all. I think it's impossible to ever know what really happened just from the media.
Zimmerman is obviously guilty of wrongdoing, to what extent though I'm not sure. He is either an overzealous neighbor who made bad judgment or a cold blooded murderer, an important distinction.
It's possible that there's a good reason why he hasn't been arrested and not just that the PD is corrupt. Though that is also possible.
The article I linked to earlier said that witnesses saw him kneeled over Trayvon's body after the shooting, indicating that he felt remorse for the shooting.
The reason he's not arrested was a claim of self defense..
The 911 tapes that the police withheld for a decent while are pretty damning..
He admits to stalking the kid, he then ignores the 911 dispatcher telling him they don't need him to follow the kid, then he reports that the kids was fleeing after he noticed him and then he pursues the fleeing kid...
He can't claim self defense if he pursued a fleeing minor. He isn't an official authority, he's a self-appointed volunteer neighbourhood watch guy... and he ignored dispatchers that told him officers would handle the situation...
And before the kid died you can hear him screaming for help loudly in fear and panic before the gunshot silences him...
The police have tried to correct witness statements that corroborated with the withheld 911 tapes of the kid screaming for help.
They have changed up Zimmermans account of what happened(the offical story now is the kid attacked him from behind as he left the car, again the 911 tapes refute that) , even when the 911 tapes contradict him...
People generally feel remorse when they can register how much they fucked up, that doesn't take away from the fact that they fucked up nor does it make it an accident...