Leftists aren't doing themselves any favor by this compulsive photoshopping and nor by conflating generic insanity with political or ideological motivations. His ex was a Mormon and the relationship was a disaster. Couple that with -- apparently -- untreated PTSD and you have the entirety of the fellow's motivation.
In other words this was NOT a typically insane and violent leftist motivated by toxic ideology and primed to commit murder by his fellow leftist buddies.