If you kill someone, you practically took away his chance to life a full life. Given you cannot bring him back to life, there is really no other way to be responsible unless your chance is take away too. The difference between life and non life sentence is not a fundamental difference but simply scale, in my opinion.
Another thing is...punishment by law is just one form of punishment, in many way it is the more civil punishment too, even if law doesn't get to you, will your social circle accept you? If crime goes unpunished, you probably won't find a place in the society besides among other criminals, and psychologically you won't get over it.
Another thing is...punishment by law is just one form of punishment, in many way it is the more civil punishment too, even if law doesn't get to you, will your social circle accept you? If crime goes unpunished, you probably won't find a place in the society besides among other criminals, and psychologically you won't get over it.