Elaborate please. I never heard of the weapon malfunctioning.
According to the police, Trayvon was shot once in the chest, one shell casing was found on the ground and the magazine was still full. This is not how semi-automatics work. When a semi-automatic weapon is fired, the bullet travels out the barrel, the slide cycles backward ejecting the empty shell and another round is drawn from the magazine and inserted in the chamber ready to fire. So each time the trigger is pulled, a shell is ejected and another round is placed in the chamber until the magazine is empty. At that point, the slide remains locked in the open position, waiting to be cycled manually. If the stories are being reported accurately (and given the news media’s consistent lying in this case that’s certainly not a given), then this is not normal behavior.
There is a way to fire a round without cycling the slide. If you put a hand on the slide to hold it in place and then pull the trigger, you can prevent the normal cycle. In that case, the magazine would remain full.
If Trayvon was grabbing the gun, this could explain the situation.
Zimmerman got off one shot. The KelTec he had, failed to chamber another cartridge. It did not jam. That means something prevented the slide from cycling. Zimmerman would have had a very difficult time racking the slide with Martin on top of him if the first shot hadn’t been so lethal.
Either Martin had his hand on the slide when the gun was fired. It was jammed between the two bodies. Or Zimmerman limp wristed the gun when it was fired allowing it to move so much the recoil that would have normally cycled the slide and chambered another round caused the gun to flop around.