I’m no where near your point of view. Yours is the point of view of the idiots that blame everything but the perpetrator. Yours is the point of view the left had when Loughner went on his rampage last year, blaming conservatism.
The real thing to get from that link is that his mother knew he had issues and did nothing for it.
Right there in your paragraph we see the problem with your point of view. The Joker’s colors are purple and green, the Joker’s colors have been purple and green for 60 years with no variation. And the only time in that stretch when the Joker had any facial hair was when Caesar Romero refused to shave so they applied the makeup over his trademark mustache. So an idiot with red hair, a goatee and dressed all in black is most certainly NOT self emulating or self identifying as the Joker. It’s not a matter of not modeling precisely to a T, he didn’t model even slightly AT ALL.
Still, you're getting (I hope unintentionally)sidetracked in details. In the end nothing hinges on whether or not he was really in full costume, and I think you realize that as well. He was by all reports immersed in dark and violent fantasy pursuits, which I contend played some role here; you firmly assert it didn't-- that is the crux of the issue. And, reportedly, he told the cops upon arrest that he was "The Joker." Not sure how anyone can wiggle out of that obvious choke-hold, claiming it isn't relevant to whether or not he was influenced by the glorification of evil and violence he admired so much he emulated it. But go right ahead.
The real thing to get from that link is that his mother knew he had issues and did nothing for it.
Oh, point an accusing finger at Mom instead of the gunman. I see. /lame argument
I'm convinced we will eventually learn there's plenty of blame to go around here, dynamics we cannot possibly even speculate on right now,(as someone recently said: "you didn't do that by yourself") but the majority of blame lies with the killer who knew what he was doing, and chose it. And that won't change.