One issue is everyone taking one shot to kill like in RO2 is that it can make the fights kind of easy. Part of what would make a real fight more difficult is that you don't know for sure if you've got somebody. You pop out of cover, shoot somebody, he just shoots you back, you know? A lot of cops have died like that.
Which is probably why they spray bullets from their pistols until their target goes down or they run out of bullets (to the detriment of bystanders).
Back on games, have you played the original Deus Ex? On Realistic? If you shoot a regular human enemy early in the game in the head with your basic pistol, they die. But their bullets to your head are just as lethal, and your foes have pretty accurate aim up close. Mind you, it's a game where you're a nano-technologically augmented agent in a plausible semi-near-ish future world.
The correct thing to do is Mozambique with a shot to the head. The whole psychology thing we were just on means if you shoot somebody twice in the chest and he doesn't go down, continuing to shoot him in the chest isn't going to change much.
As for what cops do, I don't know what cops do, I haven't done that research. I do know that this is bay12 and on bay12 cops drive through the streets cranking gatling guns from the backs of trucks and their guns won't holster until they've drawn dog blood, so I'll defer to that.
Deus Ex wasn't really my style. I do play Planetside 2. I might try STALKER again, the original, I don't think I've ever really played it with a high end computer so it should be interesting to see how it looks at maximum settings with texture mods and Lost Alpha and everything else. Or maybe the old Realism mod which made the guns so sexy without making enormous changes to the gameplay like Kanyhalos and Lost Alpha. ONe of the things I don't like about STALKER is the royalty-free guns and the limp, airy sound effects and ragdolls.
That's one thing RO2 gets beautifully right. The sound effects and the weighty feel of guns and the way people go down.