Glad to see someone else who knows their stuff! I'm a psych major so it's all very fascinating to me. When I was creating Fletcher it was very important for me to get the details right and not just copy some Hollywood rendition. Psychopathy isn't my major area of interest in Psychology so I had to brush up by reading official police/FBI training manuals on how to deal with psychopaths as well as other stuff. It's all quite interesting. I would be lying, however, if Heath Ledger's Joker didn't impact Fletcher's personality in a small way :)