Fatal Hits Not Always Immediate

"Generally speaking, one or more good center hits to the upper chest will end the fight quickly [with a handgun], but there are exceptions. A heart shot deer will often run about 50 yards before collapsing. Why? Because even though there has been a sudden loss of blood pressure, there is still enough oxygen in its system to sustain it for 15 or 20 seconds. This sometimes happens with humans as well. A determined adversary will often stay on his feet and keep fighting for 15, 20, or even 30 seconds after he has been fatally hit. A lot of damage can be done in this length of time...Always keep this in mind and be prepared to take further action if you are faced with a failure to stop.”

Rick Miller