I've been thinking all morning—and all last night and all yesterday—about Adam Lee Brown, the guy who attacked and stabbed a 10-year-old in a Portland Wendy's on Sunday. Today's news that he not only assaulted many other children in his past, but intentionally tried to infect them with AIDS makes my eyes hot and my throat tight.

He is a nightmare. He is a BOB from Twin Peaks, a statistically impossible human whose actions are a cattle prod to the spooky, vulnerable, irrational part of my brain. People like him—and fictional versions of people like him—are the reason I sleep with a baseball bat by my bed; I need a talisman to look to when I hear a sound outside and imagine his face in the dark.

One reason I envy religious people is that religion gives clear explanations for terrible things: "Adam Brown is the devil. He is evil." In contrast, my faith that we're all just slightly unique arrangements of carbon atoms leaves me woefully at a loss to explain those people and events so terrible that they seem supernatural.

So how can we react to him? I think, without religion, I'll never be able to understand why someone's brain can be so out of whack that they'll want to subject children to random horror. The more productive question is how his behavior should affect my behavior and our behavior, as people who depend heavily on a group of agreed-upon cultural systems—our government—to keep us safe.

We tend to make prison policy around our knee-jerk reaction to people like Adam Brown: Lock him up, lock him up FOREVER. Along with him, lock up anyone who shows any inclination toward horror, lock them up forever. But though it's a psychic salve against irrational violence, rather indiscriminately putting increasingly more people in prison for longer don't make our society better in whole. We have the world's highest rate of incarceration, yet our murder rate is the same as countries that imprison a far smaller fraction of its population than we do, plus we have the added problems of busted budgets, unemployable ex-convicts, and broken families. Saying we should build our most significant prison policies around aberrations like Brown is as irrational as saying we should ward off crime by never going to a Wendy's again.

I think there are two truths here. One is that when we underfund social services—like mental health care—it's the most vulnerable people among us who suffer the most. The other is that no safety system is fail proof. However much we fortify our jails, however many parole officers we hire, however many baseball bats we store by our beds, every once in a while, someone is going to slip through and commit violence against someone else. Adams was supposed to die in prison: He had AIDS and was considered terminal in 1993. He's a fluke. A fluke of medicine, justice, and society. He's the kind of terror that we can only cross our fingers and hope against. But meanwhile, we should make sure our social systems are functioning in a way that has the fewest number of cracks for people to slip through as possible.