You can kill the body, but you cannot kill the soul. The spirit is eternal. When one takes the life of another deliberately, there is always payment at a soul level. Judgment comes not from a vengeful deity, but from within the self-same soul. Judge not another, for that other will judge themselves when shown the full effect of their actions.
Much that you consider wrong is the result of ignorance—ignorance of the very nature of Life and of the Great Spirit. All of life is the expression of the God Force. Killing and mayhem are the willful uses of this force gone awry. Why is there such disharmony when these acts occur? For the soul knows wrong from right.
Those who do not see the difference while here in physical form will most certainly see it when they pass over and review their life. When understanding comes, so also comes the great urge to do better and to express in a far greater way the true Spirit. Souls may become temporarily lost, but all eventually find their way home. Meanwhile, maintain hope for mankind and be a model of loving kindness.