Not so crazy.
Another interesting thing to note about all of these mass shooting perps is the fact that they all seemed to have been on some form of antipsychotic or antidepressant medication. Not saying that this was responsible for their actions, but it bears consideration.
The shooter claimed that he was receiving instructions remotely by some sort of microwave device. The CIA has a long and illustrious history of experimentation with "artificial telepathy": behavior modification and remote transmission of covert programming to (sometimes unaware) operatives via HF and ELF frequencies. Projects wih colorful names like Project Moonstruck, MKULTRA and MKDELTA have been in the works since the 1950s.
Dr. Robert O. Becker, who was twice nominated for the Nobel Prize, said this about artificial telepathy: "such a device has obvious applications in covert operations designed to drive a target crazy with "voices" or deliver undetected instructions to a programmed assassin."
I admit, this is delving deep into tinfoil-hat territory, and it is not really my intention to take the thread there, but it does bear at least a passing thought.
What if the shooter wasn't crazy at all, and had no idea what he was doing?
One final word about mental illness and mass shooters: Charles Whitman, perpetrator of one of the most deadly mass-shooting sprees in history, wrote in his journal that he would like his brain examined after he died, so that science could find out what his problem was. What the medical examiner found was a tumor pressing on his amygdala, the "emotional center" of the brain. It's not clear how much of Whitman's crimes can be attributed to his disorder, but one thing is certain.
He was the one ultimately held responsible for his actions, not his weapons.
It was a different country then.