Rainsford killed Zaroff in self defense. P-Against his will Rainsford was forced to participate in a 3 day hunt where Zaroff tried to hunt and kill Rainsford. While it is clear that Rainsford did kill Zaroff, this killing was not murder, but rather an action of self-defense because Zaroff was a psychotic and deranged killer who would have killed Rainsford if he had not defended himself.