Have you all read this article? It raises some good questions about the limits of nonfiction. The author certainly tests them, as he at times writes from the perspective of the shooter. As far as I know, the shooter left no record of his actual thoughts right before the event, but the author claims to know them and presents them alongside facts and verifiable information.
Members of my department have been engaged in an online discussion about it, and the author recently posted on it. He did not, however, answer the question most people are asking, which is – where did he get the information? He claimed everything he wrote was “grounded in fact.” Interesting. What do you think?
http://www.esquire.com/features/steven-kazmierczak-0808?click=pp