Sleep disorders don’t necessarily evolve into a human skull in the backyard. He was into drugs - courtesy of a cartel who also engage in mindless, heinous acts. He was a scary, left winger on a mission to kill people. His victims were all “typical” white people (what Obama calls them.) He didn’t shoot anybody else.
As more info has come out about this nutball I can see that he’s just mentally deranged, period. Although it is not untrue that an imbalanced person with drastic sleep depravation could go off the deep end very easily.