Double Effect

The object of Carl Lee killing the two men that raped his 10 year old daughter is evil. The intention, however, is pure because his motivation for killing the men was to prevent them from raping or killing other girls in the future. The problem is, you can not reach the good effect without first comitting the evil action. In orrder for Carl Lee to prevent the men from raping more young girls, he had to kill them. The good effect balances the evil effect because by killing the two men, Carl Lee was able to prevent them from ever comitting such an evil and brutal crime again.