Alternative Character Interpretation: Given the sequels weren't made into movies, would this version of Aaron still develop into the more murderous and depraved one that Stampler was in the books? While it is left to the Aborted Arc angle either way, on one hand, it's potentially implied at this point that he already started murdering all the other altar boys who were also Rushman's victims and thus would go in the exact same direction as a result. On the other though, while Aaron here also does have the background of his father being abusive, he's showing Vail way more Villain Respect in the end than he did in the book and therefore, this version at least comes off as a far more graceful person as a result too.
Edward Norton losing the Best Villain award at the MTV Movie Awards as well.
Complete Monster: John Shaughnessy is a crooked State's Attorney willing to do anything to satisfy his greed and cover up his corruption. Dealing in Police Brutality and criminal business on a daily basis, Shaughnessy masterminded a scheme to force hundreds of poor and minority people onto the streets and tear their homes down for profit. When his partner, Archbishop Rushman, backed out of the scheme, Shaughnessy threatened him with death, and later kills local good-hearted crime boss Joey Piñero for disobeying orders. Shaughnessy's true evil comes from the fact that he deliberately covered up and suppressed evidence and victims of Rushman's vile sexual abuse of teenagers, Shaughnessy enabling Rushman to continue his abuse for decades so long as he was profitable. Shaughnessy later tries to get the death penalty for Aaron Stampler—one of Rushman's victims who killed the man to escape the abuse—just to keep the cover-up quiet, and promises to ruin the career and life of lead prosecutor of the case, Janet Venable, if she fails.
In the court scene when Venable rants about how she would have stabbed the archbishop 78 times, cut off his fingers, gouge out his eyes,etc, she is actually making an excellent case for Aaron/Roy to be let off with a short sentence for manslaughter or even acquitted altogether for justifiable homicide. Aaron/Roy is highly intelligent and can obviously see that. So why did he go into open Roy mode and assault her?
Here, Edward Norton fakes a split personality. In Fight Club, he really does have a split personality.
When asked what Aaron looks like, Martin replies "like a Boy Scout." Edward Norton would later go on to play the Scout Master to the Khaki Scouts in Moonrise Kingdom.
Magnificent Bastard: Aaron Stampler is an orphaned altar boy who was forced into performing sexual acts on camera by Archbishop Richard Rushman. Brutally murdering Rushman for his abuse—and apparently murdering Rushman's likely accomplice Linda too, Aaron then conceives of faking a multiple personality disorder to cast reasonable doubt on his own guilt. In doing so, Aaron acts like his regular self is a timid and stuttering kid while his more aggressive personality "Roy" is the strong defensive one who committed the murder to protect him—with Aaron supposedly not remembering any of this due to blackouts. Fooling both his own defense attorney Martin Vail and psychiatrist Dr. Molly Arrington, Aaron then stages a mental break in court by means of Roy attacking prosecutor Janet Venable and the judge finds he's not fit to stand trial as a result. Purposely letting the truth slip to Vail, Aaron then tries to graciously get a horrified Vail to share in his victory with him.
You have to give credit to Roy for managing to construct a "nice guy" persona and masterfully trick people into thinking that one is the real personality for years.
Similarly, Martin Vail gets one for Spotting the Thread, as Aaron slipped up and mentioned the prosecutor's neck - when he was supposed to have "lost time" during his attack on her, and Martin immediately connected the dots, to the point that he gets some Villain Respect for spotting it that quickly.
Vail exposing Shaughnessy's unscrupulous and downright evil political actions in court while also accusing him—falsely—of Rushman's murder. While Shoat ultimately strikes it all from the record as irrelevant and whether or not Shaughnessy faces consequences for any of it isn't addressed later, that Vail managed to so throughly ruin his image though is still a win in spite of that. Even better: in the sequel to the book, Vail gets his job.
