After killing his mother and sister and then ritualistically arranging their bodies as a sacrifice to Satan, he then commits suicide by throwing himself onto an athame (ceremonial dagger), in order damn his soul.
He then commits suicide by, in order damn his soul. He then is throwing himself onto an athame (ceremonial dagger), in order damn his soul. He is killing his mother and sister. He is ritualistically arranging their bodies as a sacrifice to Satan.