Clint was way ahead of his time. Back when I was on an SRT/ERT, we trained for "two center mass, one to the head" on every hostile engagement. That line of thought came from the Trooper Mark Coates (South Carolina Highway Patrol) shooting. So that was the rule of the day. Both pistol and rifle at CQB ranges. Every training day. Over, and over, and over again. We got good at it against stationary paper targets, and then with Simunitions against role players. We thought we were top shelf.
And then along came the Israelis. They knew what we didn't, based on their years of experience in real life: a head is awfully hard to hit on a moving bad guy. Especially past 5 yards, and when the average cop would have trouble hitting a barn from the inside due to combat stress. So they taught "two center mass, and then two to the pelvic triangle". Their logic was simple, and solid. One hit center mass slows them down, so you fire two. Then you put a round or two in the triangle, be it 9mm, .40, .45 ACP, or .223/5.56, and there's a really good chance you hit a major vein or artery. Plus you are going to shatter the hip bone, which means your bad guy...no matter how motivated they are...is (a) going to collapse on that shattered hip, and (b) going to bleed to unconsciousness in 20-30 seconds, and then suffer heart failure within a minute due to major blood loss. So we went back to square one, and started over. Two upstairs, and two downstairs. Like I said before, toughest training I ever had as a civilian.
Paid off a couple of years later when the SRT (I was out of town for the callout), confronted a guy who had killed his wife and eluded capture for two days. They tracked him to an ex-girlfriends apartment; set up surveillance; and when he came out at 11pm that night, confronted him as he approached a vehicle. He drew the same pistol he had killed his wife with, and the lead SRT deputy hit him in the 10 ring with two shots from an MP5N, and then two more on his Levi's zipper. Keyholed both groups. CPR was attempted until the Squad got there 5 or 6 minutes later, but by that point he was a Class IV patient...about 3 or 4 quarts low by Express Lube standards...and did not benefit from medical intervention or legal representation.
All I need to know.
EDIT: Can't wait for Luthers "pro tip" on how to keep me from falling off my high horse again...