I would give him the samurai suicide treatment. Y'know, where you stab the sword near your abdomen, and while bleeding (but not quite dying), churn the sword around in a circular motion. This will cause the intestines to tangle around the sword (but you're still not dead) and then you take it out. Then, you suffer the pain and die a slow, painful death. How painful :-S
i would: tell him that i do not care if he killed my parents and then when the killer faces back i would use a stunning injection then hang the killer on something then scratch his clothes off with a knife then throw the knife at various parts of the killer's body in this order: left leg,right leg,left hand,right hand,left knee,right knee, left shoulder,right shoulder,penis,abdomen,left breast,right breast, neck, and head.if i miss any i would stab it.that would teach the killer a lesson he would never forget in hell!
id rip out all their fingernails then id set alight their naughty bits then id cut of their arms then rip out their teeth then chop off their legs then slowly i would plunge a knife into their chest and if it doesnt kill them then id stab em with another knife then another and another etc.
i would first tie him to a pole, then stab him allover his legs and arms, shoot him in the stomach and then let wila animals tourture him to peices then i will stamp on his head and laugh at him