This is just a theory about who Queen's killer is. I've heard the whole 'it was Ace' theory before, but I've never seen anyone suggest this specific possibility, so I figured I'd go ahead and put it out there! So, this was sort of confirmed! He doesn't have dissociative identity disorder(that I know of, anyway), but he was the killer! Also, he most likely has schizophrenia. It's hereditary and would explain the hallucinations, paranoia, and irrational behavior.
To Mossy for making Queen's Mystery
