Pause & Post #3: Split Personality Disorder

In both posts before this one, I've said in some way Crime and Punishment is unlike any book I've ever read. And, I'm going to say it again. The plot of the book is very similar to popular series' today like CSI and Criminal Minds where someone is plotting to commit a crime (ie. a murder). In those shows, the protagonist(s), and antagonist(s) are very clear. From the beginning, as the reader, I knew Raskolnikov was the protagonist but what I didn't know he would also be the antagonist. 
Throughout the story, Raskolnikov fights this inner demon inside him. He talks to himself, and when he's thinking about murdering the pawn lady, it's almost like he's refereeing himself. He's his own enemy. He can't stop these thoughts or his murderous actions.
As I discovered this about Rasknolkov I found myself wondering if he had split personality disorder. Split personality disorder is a mental illness where people experience two (or more) different states of personality. What this means for Raskolnikov is he has the self you're introduced to at the beginning of the book, the intelligent university grad, who also lives in poverty. Later we see our protagonist talking to himself.. Which leads to...
Ones of the causes of this mental illness that I think is most is prominent in our protagonist/antagonist is stress. Rasknolikov lives in St. Petersburg, Russia where he is very poor, his mother had written him a letter saying his sister was getting married (which is disapproved of), his friend was hit and killed by a carriage, and he has little food to eat, but drinks vodka all the time. 
People with split personality disorder can have more than one other personality, but Rasknolikov  only has the one, but no matter if you have one or ten more personalities, the other 
personalit(y)(ies) is/are bad-evil. This clear is Raskolnikov.
Raskolnikov is a good person, he's intelligent and handsome, but he showed he was capable of murder. Because he was capable of murder does that make him a bad person? Or can he still be thought of as a good person?