I got that from an instructor in the late 60s-70s (one fast shot
towards the bad guy as soon as you can get it off, then an aimed
double tap) but that was modified to just a double tap.
I don't actually see that. It seems they can't seem to fire less than
6 or 7 and most of the time it is a magazine dump. Most of the rounds
are in the wind.
Remember the guy they shot in New York, they fired about 40 rounds
among several cops and hit 10 innocent bystanders.
One of my buddys is a retired GA SP Captain. They were trained thusly.
AIM, one to the torso, one to the head, repeat if necessary.