It's best to wait till tomorrow to discover exactly what we actually know about what happened today. I've now read so many conflicting reports and rumors and speculation about motives that I'm dizzy. We do know now though that the killer is alive, and so some greater understanding will be possible soon. And we also know, despite frenzied speculation, that there was one gunman.
As soon as we have some reliable facts to interpret we'll join the fray. Until then, some restraint. But please pray for all those murdered and their families.