[tropo]

That depends on where you live. In many places, the law doesn't punish victims for self-defense. You certainly can kill a person who is attacking you. In a few places, notably Texas, it is legal to kill a person to stop a theft or to recover stolen property, as long as there is no non-lethal way to do so.

[vincnetas]

Yes i stand corrected. I had my country LT in mind. But as you self write “ as long as there is no non-lethal way to do so.” Same probabbly for rape. If guy trying to commit rape changes his mind just by seeing a gun, and stops, it would be illegal for you just to open fire and kill him.

[tropo]

Legal standards vary. In most of the USA, he probably could be shot.

In nearly all of the USA, he could be shot if he were in the victim's home. Most states do not have a duty to flee when in the home, and the attacker's continued presence is considered a threat. Only in Vermont and Washington, D.C. is there a duty to attempt to flee when in the home.

Outside the home, in most states he probably could be shot, at least if he weren't clearly departing. He can't just stay there being a threat. There is no duty for the victim to attempt to flee, even if outside the home.

An interesting case involves a purse snatcher in a Texas parking lot. A bystander pulled out a huge revolver with a laser sight, fired, and killed the purse snatcher to recover the purse. It was legal.