Kastigar said that, in the video, Roll pushes Barber to the ground, protects him with his own body and tries to push the two away from the gunman, who was just feet away and shooting indiscriminately into the crowd. It was at that moment that Roll was shot in the back. He was killed.
Barber was shot twice and underwent multiple surgeries. He was released from the hospital on Friday and attended Roll's funeral.
The video also shows the suspected gunman, Jared Loughner, shooting Giffords from just two or three feet away. Footage also shows a sheriff's deputy removing earplugs from the gunman after the shooting. Video from before the shooting, when Loughner allegedly went inside the supermarket to get change for his cab driver, shows him pointing to his ears as he explains to the clerk that he can't hear with his earplugs in.
The Washington Post reports today that Loughner may have been able to buy his gun thanks to a Clinton-era memo that "prohibited the military from reporting certain drug abusers to the FBI, which manages the national list of prohibited gun-buyers." Loughner had been rejected by the Army after he admitted to smoking marijuana.