1. This was not an act of "senseless violence". Calling the violence "senseless" implies that the shooter has no moral agency. What occurred on Wednesday night was not "senseless violence" -- it was a cold, calculated, act of racial hatred. (While I love Anderson Cooper and watch his news program nearly every day, he's really dropped the ball here.)
2. Some have suggested that the shooter "obviously" suffers from some "mental illness". Thing is, mental illness doesn't make us kill one another. Mental illness demands to be treated with compassion. When we call this event "senseless violence" or attribute some "mental illness" to the shooter, we blur the lines between evil and illness. Christians can only do this when we deprive our moral language of responsibility and forgiveness. If there's ever a chance for any forgiveness, we must call things what they are first. (I've seen this most often from the folks who should know better -- trained Christian psychologists.)
3. I've seen countless folks highlight the racial injustice at the hands of the police, in the way this arrest was handled vs. the arrests of black folks in recent months. Yes, police brutality merits our full attention. But it's not a bad thing that this shooter was apprehended without violence. It's not a bad thing that this shooter will see a trial. Protesting a moment when justice works (as in this case) is misguided. Don't protest a job well done; protest all those other jobs poorly done. (Any number of my liberal friends have been sharing the image of that tweet this week.)
Developing and honing the moral vocabulary necessary in dealing with this shooting is part of what it means to be a Christian. We can't call racism, murder and injustice evil unless we have the moral vocabulary that renders content to those terms. And we can't develop that vocabulary without the lives of discipleship to Jesus.