Nice in theory, but tell it to the expert New Mexico marksman who grabbed his .45 to take out a crazy with an AK doing a mass shooting.
Bam! The bad guy went down on the other side of a car. The marksman turned to go around the car and make sure he was out, when bam, bam, bam, the bad guy popped back up and nailed him. As the good guy was down by the curb, the bad guy walked up to him and finished him with a shot to the head.
It turns out the bad guy was wearing body armor.
Keep shooting until the threat is down and no longer a threat. Don’t assume that just because they go down, that they are out of the fight.
I assume you are a cop? I have never seen anyone get up from a shot to the head.
Never turn your back on an assailant, down or not. Not until you see the toe tag tied on or the bag zipped up.