Flowers and notes of hope and support from the community...

Flowers and notes of hope and support from the community line the sidewalk, Friday, June 19, 2015 in front of the Emanuel AME Church in Charleston, S.C. Dylann Storm Roof, 21, is accused of killing nine people during a Wednesday night Bible study at the church. Credit: AP / Stephen B. Morton

It's been several days since the latest mass slaughter traumatized our nation. Few of us have not been roiled.

We reel from profound sorrow to utter disbelief. We find ourselves angry, then bewildered. We cry, for the victims and for the ability of some to forgive so quickly. And we contemplate the evil that produced the bloodshed.

And somewhere in the process comes the inevitable relief when we learn that the killer acted alone. Because it's easier to deal with when we can write him off like that, like he's an aberration. Like there's no one else out there.

But it's false comfort, this myth of the outlier. Because the truth is that the lone gunman is never the only gunman. There's always someone else in that long line, and there are always other targets. What happened in Emanuel AME Church in Charleston, South Carolina, is not an aberration. It's part of a pattern that bludgeons us again and again. And it's a dark and ugly and exceedingly uncomfortable part of who we are.

Sadly, we all know the drill. Someone among us emerges from some internal swamp of inchoate rage and commits an awful act. A shocked country wrestles with the aftermath. An outpouring of love and sympathy engulfs a community. Then quiet. And, at some point, the cycle resumes.

The savagery in Charleston took place in a church. It was unimaginable. But how much more horrifying or unbelievable was that than an elementary school in Newtown, Connecticut? Or a high school in Columbine, Colorado? Or a college campus in Blacksburg, Virginia? Or a military base in Fort Hood, Texas? Or a sorority house in Santa Barbara, California? Or a movie theater in Aurora, Colorado? Or a supermarket in Tucson, Arizona?

Face it, our nation is bathed in violence. We own more guns than any place on Earth. We kill more of our fellow citizens than any other developed nation. We glorify violence in our movies, our music and our video games. We mythologize and romanticize the fictional lone avenger of injustice, whether it's Charles Bronson or Sylvester Stallone or Liam Neeson. And we're surprised when that's what we get for real.

Dylann Storm Roof, the alleged Charleston killer, perceived injustice. He saw himself -- and his race -- as victims. "Their" world was being taken away by blacks. And he wanted to start a race war to take it back.

How many warning signs were missed along the way? Friends talk now about the things Roof said, the racist jokes he made, the violence he said he wanted to commit. Facebook photos show him in a jacket adorned with flags of white-supremacist Rhodesia and apartheid-era South Africa. One friend took away his gun, briefly. No one derailed him. How do you know when?

So we end up with nine people killed and the story of a 5-year-old girl surviving the bloodbath by curling up on the floor and pretending to be dead. That's what they teach in school these days -- active-shooter drills, along with your ABCs.

How can this be?

These spasms of extreme violence keep coming, they beg for a meaningful response, yet we make little progress. On racial tolerance. On mental illness. On gun control. On disaffected youth. On our collective responsibility to cry out when we see hints of trouble.

We're locked in perpetual replay, mourning and standing in solidarity with the dead and their families. We offer our fellowship and support. Most of us, anyway.

The others are still out there.

Michael Dobie is a member of the Newsday editorial board.