<https://de.wikipedia.org/wiki/Finaler_Rettungsschuss> Details this a bit better; most shots fired by the german police aim to incapacitate an opponent or are fired in a perceived or real emergency situation, the prevention of crimes and prevention of getaway.
The difference between the mentioned cases and the "final and fatal shot" is that the later is used by the police officer with the express and only intent to kill. There are various requirements, mainly that it must be the only viable way to prevent lethal or extensive harm to others.
Please note that the english pages are not as extensive or talk about the US situation so they're less useful.