Retail massacre, on the other hand, is the work of loners and losers. These massacres usually have elements of nuttiness, malicious imagination and obsession with information that is easily distorted through a lens of madness. That's the way of religious fanatics drawn to terrorism, like the Army major at Fort Hood, Texas, who imagined he was a soldier of Allah. (President Obama wants us to regard the Fort Hood massacre not as terrorism but as "workplace violence," but almost nobody else does.)
Killers can be the mentally mangled with the means to destroy, like the killers at Columbine.
They can also be deranged by something like an aggressive tumor on the brain. Charles Whitman, the sniper in the tower at the University of Texas, was a onetime Eagle Scout who suffered an unknown swelling until it pressed itself into the service of violent behavior. An autopsy discovered the tumor. Science and psychiatry can tell us much in laboratory and asylum, but there's still much we don't know and can't explain, or even attempt to understand, until tragedy disrupts the calm of conventional lives.
Aristotle described tragic theater as exciting the emotions of pity and fear -- "there but for the grace of God go I" -- and such emotions can turn evil in modern everyday life. We look for scapegoats and even identify a few, but the loss of innocent life seems most fathomable by simply recognizing that death by massacre is pure bad luck, just being in the wrong place at the wrong time.
The more we learn more about alleged gunman James Holmes and his habits, the more we're likely to ask whether any drugs played a part in his murderous rampage and whether his obsession with a nonviolent video game contributed to a psychotic personality. Something called "i-craziness" (the "i" is for Internet), or "connection addiction," is thought to contribute to panic, depression, psychosis and even rewiring brains.
Scientific research supports anecdotal observations that ultra-smart technology may in certain circumstances control the "controller," or bring on a "reactive psychosis," a form of temporary insanity.