The following has to do with taking head shots in the heat of the moment and is in response to the original post linked below.
I would just like to point out something about head shots...
Unless you hit and destroy the medulla oblongata (brain stem, see attached diagram), a very small target indeed within the skull, there is a distinct possibility of the BG having an electrical storm in the brain causing him to involuntarily fire his gun and quite possibly killing the store manager.
Second, it is easy to sit back in the comfort of your home and talk about how you would play out the original scenario here. (Nothing wrong with that btw... but you don't have the real life stressors and adrenalin surging through your veins as you would when the situation is actually playing out before your eyes.)
If anyone has ever experienced an adrenalin dump and being in a full blown "fight or flight" response you will know that it is just about impossible to maintain the "fine motor coordination" needed to take a shot like that (unless the muzzle of your gun is literally pressed against the back of his head).
In the stress of a real life shooting when you are scared, trying to make sure you have all the facts, chaos running through your mind and with the large amounts of adrenalin and norepinephrine surging through your body, you will be shaking almost uncontrollably.
You may be experiencing "tunnel vision" and may not even hear critical things happening around you. And while things may appear to be happening in slow motion, they will be in fact happening "lightning" fast. (All are normal responses to "fight or flight".) Attempting to make an absolute precision shot under real life or death circumstances more than likely will have disastrous results.
Regarding the legalities... Say two BG's go into a store to rob it. BG #1 has a gun. The store clerk pulls a gun and shoots BG #1 and he dies. Usually BG #2 gets charged with BG #1's murder. Say the same situation happens and before BG #1 dies, he shoots and kills store clerk. Same thing, BG #2 “usually” gets charged with both murders.
Now in this "Original Scenario" of one BG holding store clerk with gun to his head. You "the lawful ccw holder" shoots BG in head, he in turn pulls trigger and kills store clerk (more than likely, that is what will happen) and both die. Hopefully, and rightly so, they should hold the BG responsible for the death of the store clerk (even though the BG is dead). But we are talking reality... and in reality, the right thing does not always happen. More than likely, the prosecutor will say that there has to be a live person who is going to be held accountable in the death of not one, but two people. The store clerks family may even be demanding it. Well, You are the only one left standing in which to point the finger at! The prosecutor will argue that how could you possibly know for certain that the BG intended to actually shoot the store clerk.
And that is just the criminal case. That say’s nothing of the civil liability the store clerks family or the BG's family may pursue against you.
I for one would not want to be caught up in a nightmare scenario like that. I would pray like never before that the BG got his "loot" and leaves without anyone firing a shot. If the BG does go ahead and shoot the clerk, I'd shoot before he had a chance to kill me or anyone else. Maybe a cold thing to say or do, but my goal is to come home to my family alive and in one piece and not violate the law in the process.
See diagram below:
Medulla Oblongata (Brain Stem) is the medium shade grey object that sits above the brown colored Spinal Cord in the diagram (view from the back looking forward).
video Judicious Use of Deadly Force by Massad Ayoob.
Available in VHS & DVD 130 min. at the Police Bookshelf http://www.ayoob.com/
video The Physio-Psychological Aspects of Violent Encounters by Massad Ayoob.
Available in VHS 120 min. at the Police Bookshelf