I don't know. The US is roughly 70% Christian, so I would wager that many of "these killers" you're referring to identify as Christian. I didn't mention shootings in my post tho. Our country has a growing issue with the radical, fundamentalist, white, Christian, right-wing. On levels that span hate speech and propaganda, to violence and mass murder. The motive of latest act of murder has yet to be determined, so we'll see.
But if it is an act of religion and pro-life, are Christians and Pro-Life advocates, and I'm talking large orgs that represent them and not just individuals, ready to speak up against this? It's what they've asked of the Muslim community, I would like to see them put their money where their mouth is and really show opposition to this type of behavior. I'll hold my breath.
I think our country has a problem with this along all sectors of society. Not just right wing, white Christians. Especially the "hate" speech and propaganda.
I agree that what is good for the goose is good for the gander on your Muslim comment.
But yes domestic terrorism is a troubling problem on the rise.