'I was so miserable. I wanted to kill myself. I just couldn't take anymore. I am a worthless subhuman, a living, breathing disgrace,' the 17-year-old gunman allegedly wrote. 'All my [in real life] friends outgrew me, act like they didn't f***ing know me. Becoming me was so f***ing humiliating. That's why I spend all day dissociating.' Much of the rest of the document, which was said to be linked to a social media account linked to Henderson, deals with his struggle with race and racial issues. Henderson allegedly said that he was 'ashamed to be black,' before he goes on...