Your thoughts on this scenario?

I do not support violently torturing anyone, no matter the underlying reason. The fact that he "let the man live" almost makes his crime worse, showing that all he is interested in is hurting this other person.

Yes, he most certainly should spend time in prison, or face whatever other punishment is deemed appropriate by a court of law.

There is a difference in your scenarios. The second implies that the reaction was immediate, not planned over many years, and was used as an extension of self-defense (defending another person from serious, immediate harm). Whether the man in this second scenario should be prosecuted depends upon the circumstances. Could you elaborate upon this situation?

Live long and prosper.

He should do the time. Look I would be absolutley beyond pissed but their is a reason why courts give the advantage to criminals because their is a damn possibility they could be innocent. While the man does get off we have to have a justice system for a reason. We can't have vigilantes running around doing whatever they want because they don't agree with the decision. We all know he did it but without any evidence its circumstantial. We cannot just let people carry out their own brand of justice. He better hope its worth it. Because as every movie says Vengeance is not worth it. I would want to kill him with my own two hands but if he has that much energy I would be looking out for the evidence somewhere to file an appeal. We don't want vengeance we want justice. The justice system isn't perfect neither were the people who created it but it was made with the intention of doing good and thats what we need to keep in mine. Rally organizations, get the governor involved, get it on t.v. If you have the energy to hunt down and murder him in such a cruel and vindictive way you could put that mind to how you can get justice not vengeance. To me it would be dishonoring the memory of my wife and son by killing a better way is to get justice because the dead don't care about vengeance they want justice.

It isn't manslaughter if the victim is alive. Grievous bodily harm, maybe. Not a lawyer.

To your first scenario, yes he should serve his term. To the second, no, he was acting to protect his daughter.

EDIT: The big word here is premeditation. The first scenario was a premeditated action and therefore counts against him, also that the victim was a free man according to the law, it can't matter that the finding might have been corrupted. The second scenario would be counted as "heat of the moment", the victim was caught in the act. In fact if anything the father can plead innocent due to diminished capacity.

all criminals must be stopped, regardless of the reason. Old Henry David Thoreau said You must do the Time even if your law breaking/civil disobedience is moral.

Society based totally on revenge is overdue for disintegration ... sound like today?

This sort of thing is why most jurisdictions have a statute that deals with "justifiable homicide."