And then, of course, there is religion. Some are desperate to insinuate Cho as a deranged warrior for Christ. But Cho had "Ismail Ax" written in red ink on his arm. Ismail is the Muslim spelling of Ishmael, which has caused others to speculate that Cho was another Johnny Taliban. But then, he spelled the name Ishmael - the common Western spelling - on the return address of the package he sent to NBC.
That package also contained a multimedia suicide note in which Cho both denounced Christianity and put himself in the role of Jesus Christ, even as he struck a mimicking pose possibly lifted from a Korean action movie and carried on like one of the professional wrestlers he so admired.
His execrable writings contain countless allusions to pedophilia and abuse so offensive that even his presumably sophisticatedly desensitized classmates refused to read them. His video testimony contains quasi-Marxist denunciations of materialism.
In short, this deranged young man had a maelstrom of demons swirling about him. But partisans want us to pick one all-explanatory demon.
With the light of hindsight, some say the warning signs should have been spotted. But this assumes that strange and disgruntled people are a rarity and that all of them are candidates to become mass murderers. The reality is almost exactly the opposite. Strange minds and tortured souls are all around us, particularly on college campuses.
Shall we now have the psychological equivalent of the zero-tolerance mania that causes children with aspirin to be carted off by police? Shall we unleash the white coats on every misanthrope and muttering grudge holder?
I confess, I've played the game of trying to find meaning in tragedy more than once myself and I probably will again. But not this time. Not with Cho. The only meaning I can find supported by the horrific, heartrending evidence is that once again the mystery of evil has been corroborated, the permanence of tragedy confirmed.