9. Scott Shelby (Heavy Rain)
I once read in a criminal profiling book that serial killers are often victims of a past trauma themselves. While that does not excuse what they did, it's helpful in understanding their motivations behind such a heinous act. It makes you think if Shelby would do what he did if he hadn't witnessed the death of his brother and the cruel ignorance of his father.
He couldn't believe that his father couldn't save his brother, so the trauma influenced him to find a father who was willing to go lengths to save a son even if a child dies in the process. I still feel sorry more for the victims, but I truly pity Shelby and how his past damaged him.