Trayvon Martin's DNA not found on George Zimmerman's gun, forensic tests say

(CBS/AP) ORLANDO, Fla. - George Zimmerman's DNA was the only one that could be identified on the grip of the gun used to fatally shoot 17-year-old Trayvon Martin, according to forensic tests made public Wednesday.

Pictures: George Zimmerman crime scene photos

The results rule out Martin's DNA from being on the gun's grip. Zimmerman's DNA also was identified on the gun's holster. The tests were inconclusive as to whether Martin's DNA was on the gun's holster.

Zimmerman is charged with second-degree murder for fatally shooting Martin during a confrontation in a gated community in Sanford in February. Zimmerman is pleading not guilty, claiming self-defense.

Zimmerman says Martin was on top of him, slamming his head against the ground when he grabbed his gun from a holster before Martin could get it.

Other records being released today include a photo of Zimmerman's head that was taken by a witness following a confrontation with Martin.

Complete coverage of the Trayvon Martin case on CBS News