I've yet to see a mass murderer who identified as a Liberal Democrat.
Coincidence?
No.
Ever hear of the Unibomber? He sat in a cabin in Montana making bombs to send to corporate CEO's in an effort to take out those who were ignoring climate change concerns. He had a stack of Al Gore books a mile high under his bed. LOL.
The bottom line is, this freak in the OP was asking people if they were Christians or not and then shooting them if they were.
The same thing happened at Colombine High School which was one of the first school shootings that made this kind of terrorism possible. There was also the racist dude in South Carolina who shot up Christians at a local church.
This is really about religious hate crimes and nothing more.