[imarid]

You are wrong. In most EU countries self defense has to be proportional to attack, and to be used only when necessary. So if you exceeding limits of self-defense and you kill or damage someone using forces disproportionate to the danger you can go to jail.

[afiori]

> > In most states, you can claim under almost any circumstances that a person came at you with a weapon (a rock?) and you shot them in self-defense.

A rock to the head can be quite deadly; every situation will have its own important nuances still.