Here's the quote from the supposed Facebook post of the shooter:

"I hope people call me insane... (laughing emojis).. wouldn't that just be a big ball of irony? Yeah.. I'm insane, but the only thing you people do after these shootings is 'hopes and prayers'.. or 'keep you in my thoughts'... every time... and wonder why these keep happening..."

Source: [link to www.cnn.com (secure)]