Alright lets begin with pucnhing holes in this.Ok now i have heard of this exact same scenerio happening, the guy walked in and shot the boy raping his daughter 7 times in the chest and head. Now if you say he deserves to do for ruining somebody's life, then the rapist can turn around and say "well i saw my father rape my mother many times and she never divorced him which in turn made me think rape was ok" so now you have to kill both of the kid's parents, the father for doing it, and the mother for letting it happen. I can go and shoot 30 people then say "somebody robbed me when i was a teenager so now i'm crazy so you have to kill that peson to"