Homeowner shoots, kills 14 yr old home invader.

[sarisataka]

40. In a life and death situation

It is both a fraction of a second and several minutes.

That is why I advocate mental preparation even over marksmanship. Your reasoning brain needs to keep control over your lizard brain which will screaming "DO SOMETHING"
As your body goes into overdrive, you need to force your brain into overdrive and make each of those heartbeats last as many minutes as you can... If you act too late, you may be dead, too soon you may be a murderer.
You owe it to yourself, your family and even that person in front of you, whether a young kid doing something dumb or a hardened felon, to make the choice to apply a few pounds of pressure to that trigger as reasoned of a decision as you can. Once you have committed to that pull, lives will change forever.
Also, once you act, whether to flee or fight, that lizard brain will triple its efforts to take charge. Only now it will scream "DO IT AGAIN"
You will either run faster than you ever have before you learn why so many shots get fired in an encounter.

Mentally preparing will not guarantee you will win the reason/instinct battle with yourself; but if you fail to prepare, your lizard brain will take charge and you will learn later what you did.