This looks like a case of a wannabe David Lane. No conspiracy here. He’s just bad people.
Considering there’s the flag in the upper left corner, the number 14 tattoo (the order) inside a Celtic cross (which by itself usually refers to Ireland or Scotland - but often co-opted by supremacists), this guy’s motives were clear. Neo-Nazi.
>> this guys motives were clear. Neo-Nazi.
He may have gravitated to the Neo-Nazi realm of insanity, but that doesn’t necessarily explain the depraved motivation to murder.