Charles Roberts, who methodically shot 10 girls in an Amish school, then killed himself, was a paedophile for little girls all his adult life. I don't want to get into the how and why of that, even though I have my theories. That tangent would go on for miles. Let's just say that back in the 1960s there was a very little boy and something when catastrophically wrong in his psychological, sexual mind and he ended up as a teenager who, without asking for it, had a twisted form of sexual desire that responded intensely to the idea of sex with pre-pubescent girls. Perhaps the use of non-consensual force was a component of his primary fantasy scene, perhaps not.

But he fought against these lusts and denied them all his life until the end. He had no context for such desires, no way to feel them as anything but the horrible sins and crimes they are in society. Yet they were in his head, day and night, hammering to get out. He fought to hold them in. But he had no other outlet to relieve the pressure. He repressed and repressed and repressed, then he literally exploded.

That's the very short version. I'm not trying to justify. Just explain.

Sexuality, especially paraphilic sexuality, is like the seed that won't be denied. You can bury it under boulders, and it will push out runners and creepers and eventially find the light. And all your vigilance against it can be undone in an instant, like Wordsworth's ancient tower that stood a thousand years and collapsed at once all in a heap at "the unimaginable touch of time."

People with sexual kinks wrap up a whole lot of psychology in their sexuality. With them, sexuality is more than just a drive for orgasm. It is an obsession, a fixation. It's life. They are not quite like other people. "Vampires" is an image that comes to mind, but it's hard to apply that comparison without seeming to insult. And I don't mean to. They are shaped by different forces, driven by different urges, and subject to different stresses and failures.

Sexuality is not destiny. It's not something you choose. It's something you receive, in one form or another, in one measure or another, early in life. How you cope with it, that is a different matter. Sexuality is the hand you've been dealt in life. How you play that hand is your character, your ethics.

A boy with a twisted life who grows up to be a man with endless intrusive sexual desires to, say, torture little girls, is not an evil man. If he lives a long life and manages to contain those urges and never hurts another soul out of them, he is, to me, among the greatest of the saints. Far moreso than someone who has only a vanilla sexuality and a low level of temptation.

This thoughtful article gets out the essentials in the 160-page "Child Molestation: A Behavioral Analysis," written by retired veteran FBI agent Ken Lanning, which is "the key modern tool for police officers" investigating paedophilia cases.

It outlines, in more mundane language, the distinction I hold as essential: a paedophile is not synonymous with a child molester. A paedophile "might have a sexual preference for children or fantasize about them, but 'if he does not act on that preference or those fantasies, he is not a child molester.' "

Basically, Mr. Lanning's new "typology" holds that all sex offenders fall somewhere along a motivational spectrum, from what are called "situational" offenders (these are opportunistic, tend to be less intelligent, are more likely to have a purely criminal history and, most important, don't have a true sexual preference for children) to "preferential" ones (genuine pedophiles, who prefer sex with youngsters; these fellows are primarily fantasy-driven).

The columnist then attempts to fit Roberts, the Amish schoolhouse killer, into the picture:

On the face of it, Mr. Roberts might appear to fall closer to the situational end of the spectrum, since such offenders tend to have fewer victims, and indeed for them, "sex with children may range from a once-in-a-lifetime act to a long-term pattern of behaviour."

But, because it appears from the evidence that he was fantasy-driven, it's more likely he preferred youngsters and was a preferential child molester who didn't act out very often -- or wasn't caught.

"Preferential sex offenders may be 'pillars of the community,' " Mr. Lanning writes, "and are often described as nice guys. They almost always have a means of access to children [e.g., marriage, neighbourhood, occupation]." Because, he says, the molestation of children is part of a long-term persistent pattern of behaviour, "preferential child molesters are like human evidence machines. During their lifetime they leave behind a string of victims and collection of child pornography and erotica."

Pornography to some people can be a spur to further exploration and exploitation. But to people such as I think this man was, it can be an outlet, a safety valve. Which is why I tried to test my theory on whether he had a lot of it or not.

If I'm right, he invested his whole conscious self and power and mental force to blocking these chthonic urges that tormented him. That is not unique to him. I imagine many people in the Catholic clergy, for instance, have that challenge. But he did not have a safe outlet for them, and he denied himself a support matrix. He went it alone, and he was too weak to survive.

When it broke, it broke catastrophically. He lost to it. Which meant it was going to flow out of him in an orgy (in the old Greek sense). He found the perfect target. He knew it was his death, but he was going to LIVE (in his own mind's perverted sense) before he died.

Even if this theory explain anything, it doesn't explain everything. There are repeated references, in Roberts' last messages, to a child he and his wife lost as an infant.

You also read, "He was angry with God." For what? For making him as he was? For giving him overwhelming urges and denying him the legitimate expression of them? For taking his daughter? For dangling temptation every time a little girl walked past him? For all that?

His sense of guilt and frustration, perhaps, got wrapped up in the loss of his own child. Was her death God's punishment for his urges? But who gave him those urges if not God? Hence, perhaps, his other repeated claim at the end, that he was "angry at God."

But why did he have to take the Amish girls with him when he killed himself?

There I can only guess. I think I can explain the sexual aspect and the suicide. I can only explain the massacre with reference to his complete psychological breakdown. The force that he relied on to keep him safe and sane had failed -- as he perceived it. One it fell, all restraints of morality and self-restraint fell with it. God was still real. But God now was his enemy. Killing himself wouldn't hurt God. Killing the girls would. Hence the "satanic" quality of this thing.

But I'm not sure about that. Or about any of this.