Start here. This is the police report. In particular read the essay sections by the officers:
http://cnninsession.files.wordpress.com/2012/03/martinpolicreport.pdf
Note Z was arrested then (detained, held at gunpoint and taken into custody etc.)
Note there are 6 witnesses whose names are redacted. We only know of what a few have testified to.
Notice the fairly large number of officers arriving at the scene, some (e.g., officer almost immediately after the shooting), notice that they were there a long time and sealed off the 'crime scene'.
Note the officer describing George Zimmerman's head.nose injuries.
Note no forensics have been released. The police have the gun. They have the clothes from both. There would also be GSR (gunshot residue) forensics that haven't been released.
Description of events.
I will include only known facts. I.e., claims by Zimmerman's and Taryvon's side will not be included here.
George Zimmerman, the elected Neighborhood Watch Captain, was leaving his house/apt to run errands when he noticed Trayvon. Trayvon, who lived in Miami, was visiting his father and they were staying at his father's GF house/apt in this community. So, Trayvon did not live there.
This community has had a lot of crime lately, including many robberies.
Zimmerman called 911 reporting a suspicious person. He left his car to follow Trayvon while on the phone with 911. After losing sight of Trayvon the two somehow met up and a fight broke out. Trayvon was shot in the chest and died. Zimmerman was arrested and claimed self-defense. After questioning him etc., the police concluded from their investigation and the evidence at the time they could not charge him so Zimmerman was released.
Trayvon was 17 yrs old. He was between 6' and 6' 3" and approx 150 lbs.
Zimmerman is 28 (IIRC) about 5' 9" and approx 170 lbs.
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Trayvon's side (family and supporters) claim he went to the convenience store to buy a can of ice tea and a bag of skittles for his little brother. On the way back home to his father's GF's house/apt he was chased down and killed by Zimmerman.
Zimmerman's side claims he was keeping a eye on this unknown and suspicious person. That he stopped following Trayvon and on the way back to his car Trayvon approached from behind (or left side/behind) where upon Trayvon asked Zimmerman what his problem was. Trayvon then decked Zimmerman with a punch to his nose, breaking it. Trayvon then stood over Z beating him, including slamming his head on the sidewalk. That Trayvon then saw Zimmerman's gun and tried to take it. Zimmerman, fearing for his life, regained control of his gun and shot Trayvon.
There is one witness (so far) whose testimony by-and-large backs up Zimmerman's claim.
BUT, we do not know who threw the first punch (if any, really).
There is more from Zimmerman's side, obviously this is because Trayvon is dead.
The police have not released evidence/forensics. They cannot under FL law. The Prosecutor and the police chief have stepped aside and a special prosecutor was appointed. The FBI was brought in to investigate.
We are awaiting the special prosecutor's decision as to whether Zimmerman will face charges. We would also like to know what evidence the police have. Hopefully if they don't charge Z it will be released. Otherwise, if he is charged I assume it will come out during trial.
Hopefully that helps. Just beware there has been an awful lot of misinformation in news articles. Also, a lot of pure speculation claimed as fact by both sides.
Fern