Surprising what training does for you.

yes- I know this refers to a different era - but both these responses were taught to us in training.

"Lawyer" - "Constable, why did you shoot "X" 6 times in the chest when the first shot was a fatal one."

"Constable" turns and faces the judge, not the lawyer and states. "Your Honour - I was taught to shoot centre of mass 6 times, re-load and shoot it another 6 times, repeating as long as the threat against me and the public was standing. The criminal went down on my 6th shot so I reloaded then holstered my revolver", radioed in the case then checked the criminal for life signs.

Not many years after this, 2 shots to the chest, one to the head was the drill, repeating the drill and reloading, etc., due to the odd use of protective vests worn by criminals.

With proper training, there is no time to get all psycological about -there is only time to react to training in a life threatening situation.
Centre of mass - powpowpowpowpowpow-reload-powpwopowpowpowpow-reload etc.

Perhaps some people joined police forces, who should have been working at desks or on construction jobs. Of course we all know that happens and these are the ones who get fellow police officers killed.

Once the shooting is over, show a great deal of remorse, then private, party-hearty that night - with close, trustworthy friends, of course.