Faith, if that report is true, it seems as if the gunman wanted to kill Christians relatively instantly with bullets through their heads. Minimum pain involved for the victims. Minimum suffering by victims.
Yet, he wanted to shoot non-Christians (atheists, Muslims, Jews, agnostics, Hindus, Buddhists, etc.) in the legs to suffer long, excruciating deaths; or maim them for life.
Getting rid of Christians for starters I would suppose. The others, who knows, general annoyance with the human race perhaps. Or maybe just that there he is with all this firepower and there aren't as many Christians as he thought but he's got to shoot somebody somehow. I dunno.
Or, he wanted Christians to have quick, relatively painless deaths while wanting all the other young people he shot to endure excruciating pain and suffering for life...that seems like the more logical explanation for what was reported to have happened.
Nope. Shooting a person in the legs with a powerful weapon will definitely end up in an excruciating death and/or permanent maiming. Suffering for life. You really don't have to be a rocket scientist to figure that one out.