Frank has it exactly right -- and there is an important mindset component to the "shoot to stop / wound / kill" discussion.
Almost every class, during the legal component of my material, I have a student ask me about shooting to wound. After a little back and forth, it almost always comes out that the question is driven by a reluctance to really face the reality of using a deadly weapon in self defense. They just don't want to risk killing anyone. In those cases, I look the student in the eye and say, "If you are not willing to face the idea of killing the attacker in order to save an innocent life, then a firearm is not the right tool for you to use in self defense. That's because firearms are deadly weapons. The law recognizes that these are per-se deadly weapons because there is a high risk of killing or crippling someone for life no matter where you aim on their body..."
Another mindset-related question that often comes up, driven by the same reluctance: "Can I use the gun to, you know, just tell someone to go away and leave me alone?" The reluctance behind this question is almost palpable, and it's driven by the same squeamishness that drives the shoot-to-wound query. Setting aside the legal and tactical considerations (there are many!), the mindset answer boils down to a surprising paradox: Successful violent criminals are really, really, really good at reading body language. If you're not absolutely committed to using the gun, if you're not willing to fire, the criminal will read that on your face and in your body and you will very likely have to shoot in order to save your own life. But if you are committed to action, the criminal will read that and is more likely -- no guarantee, but more likely! -- to run away. And that's the paradox. Criminals are less likely to attack those who are fully committed to defending themselves, and more likely to attack those who are not.
My personal website: Cornered Cat