"The shooter was a gun-crazed asshole who first of all, takes a gun to a movie theater (!), then draws a gun when calm rational discussion would have saved everyone a whole lot of heartache. I guess gun-crazies carry guns in order to avoid the hassle of calm, rational discussion. (too hard? too much effort?)
Fuck that guy. They should throw him under the jail..."
There is nothing calm or rational about your response. All we have to go on is what the reporter(s) chose to include, among which was a statement designed to elicit outrage and sympathy: He was texting his 3 year old daughter.
Who he was texting isn't relevant to what happened, what is relevant is what happened in that theater.
For purposes of discussion we'll say this will be a 2 week trial before it goes to the jury. We'll further say that the jury will hear about 50 hours worth from witnesses, experts and lawyers on both sides. That's 50 hours of information not available to us, most especially witnesses present that don't have an axe to grind.
Based on photos the deceased appeared to be well above 6 feet tall, appeared to be in reasonable shape and was roughly 30 years younger. Did he make verbal threats indicating he was going to kill the shooter? Who initiated the verbal disagreement when the shooter came back from speaking to theater management? How big was the shooter? Did he have medical issues? Did he or his wife have medical issue that prevented leaving the scene in a prompt manner? Was either wife threatened? Did either wife try and de-escalate the situation? Did the shooter have a past history of confronting people?
These are all relevant questions that need to be answered.