At the end of the book, Frediani is repeatedly referred to a Sociopath. How can he be diagnosed as one without a formal psycho-analysis? Can you diagnose a Sociopath purely based on behavior and surface characteristics, or is it something hidden deep within the mind? Sociopaths have several key surface characteristics. Frediani is charming, during his young days with his roommates, he seduced several women a week and many people found him pleasant company. He clearly is very spontaneous and showed very little planning behind his sexual assaults of which he never showed any guilt or shame of committing. Paul also is capable of forming intense lies, like his alibis he created in court, and will do anything to win. He proved he was willing to kill Helena just to avoid prison time for his assault. Frediani, in my opinion was also incapable of love, he abused any person he was ever in a relationship with. And last but not lease, in this novel at least, we never hear an apology from Paul for either the assault or the murder. In my opinion an obvious sociopath.