Could it go to motive?
Maybe. Perp's posts (if they are his) indicate a fixation with NASA faking their accomplishments. Giffords' hubby is an astronaut slated to fly an upcoming shuttle mission. Giffords' bro-in-law is an astronaut on the space station. So, maybe the perp shot her because he was mad at NASA. I know it sounds crazy, but the perp seems crazy.