hmmm, depends. If someone kills my family, then I take theirs?
Or what is this question about really? Are you talking about rapists, murderers or those who commit treason. Lincoln once shot a man on the white house lawn for treason, death sentence for treason. It has usually been the death sentence for treason in any country, well the US isn't so much on the death penalty for treason in the current times..hence Clinton was going to be up for charges for treason. But China executes women if the get pregnant without the Governments permission, in fact there may be that video up on youtube of the thousand or so women being executed by soldiers as they were shot in the head and half their heads were blown off in their death sentence for just getting pregnant and not being married. Pretty disgusting and disturbing video if you can find it on the web.
If someone walks into my house and they were not invited, they just made their own death sentence, either by sword or by bullet.
If its rape, then its torture and a life sentence.
If its murder without just cause, life sentence and more torture.
If a woman catches her husband cheating on her, she decides if he gets life torture or a death sentence.
Just curious to know what this question pertains to exactly.