Donald was arrested for murdering an acquaintance. At the trial, Donald takes the stand and testifies that he and the victim knew each other. He admits that they would drink and use drugs together. One night while "partying," Donald explains in his testimony, an argument got out of hand during a card game. Donald explains that the victim accused him of cheating and pulled out a knife on him and started swinging it in the air. Donald said that he had no choice but to pull out his gun and shoot the victim. The jury convicted Donald of manslaughter. What subarea of criminology would most interested in understanding the victim's role in Donald's case?