This is discussion archived from a time before the current discussion method was installed.
As to cops being trained to shoot ONLY for center mass? Not true, many police officers and military are trained for "Rhodesian Drill" which entails two shots to center mass rapidly followed by one aimed shot to the head: the theory being two body shots will drop most anyone, and if they're still alive they must have on armor, which requires you shoot them in the head.
The trope name comes from a line spoken by pro gamer FPS_Doug on the Pure Pwnage web TV series.
Is that really where the phrase comes from? It's pretty well known to be that recent, and from something so obscure. Is this an Older Than They Think