Reading his diary, he seems just a bit too into the concept of crime as art. He writes about the history of the art world's extreme fringe, and speaks of art-murder as its logical conclusion. He also describes in detail what the Minotaur did to the body, including some details that would not have been apparent from the crime scene. "No Control" and "I'm Deranged" could be his attempts to justify his actions as being not himself.
WMG / Outside
Detective Professor Nathan Adler is the Minotaur.