I think it was a Kel-Tek PF9
Yes. It was also fully loaded with a round in the chamber. Oh, and it is one of those evil black firearms. You know the kind.
I think it was carried owb in a holster with a shirt covering it for cc.
I think it was an MG42 loaded with armor piercing rounds that blow up on impact. He carried it IWB right above his butt crack. Ya know, one of those evil scary guns.
You got the pistol right Bluecow, but I think they reported the fatal round as a single Seller and Beloit 115 gr 9mm FMJ.
And it didn't have a safety
This page [1] is reporting an S&B JHP. They also mention that the jacket separated from the core into 3 pieces. Fairly poor performance, actually, but it stopped the attack and proved fatal nonetheless.
See also the FDLE report [2].
The big question is: Has it been returned to him yet?!
[1] - Law of Self Defense ? FDLE Forensic Report: Zimmerman?s Gun & Fatal Bullet
[2] - http://lawofselfdefense.com/wp-content/uploads/2013/06/FDLE-Zimmerman-Gun-Forensic-Lab-Report-3-8-12.pdf