Morally ambiguous characters
Who can guess the motivations and histories of the average person you meet on the street? The guy standing next to you waiting for the train may be about to rob a shop in another part of town. The woman standing with the suitcase smoking a cigarette may have just killed her husband. You may have gone through a red light just to get to the station in time. You have broken the law. Does that make you a criminal? Of course not! You were not caught. You got away with it. You could have stopped when the light was turning but you decided to go for it. It turned red just before you crossed. You technically committed a crime, yet you remain free. You now have an attribute of moral ambiguity.
Congratulations. You just made it to the list of interesting characters.