No, this is incorrect. Police are trained to stop a threat. Handguns despite what you see in movies are actually quite poor at doing this, so the accepted and common doctrine is “at least 5-6 rounds center mass”.
This is in life or desth situations where that person must be stopped or someone else will die.
If police were trained for one and reassess, they would shoot one. Trained for two; and they’ll a lot two regardless if they have a good sight picture after the first shot or not.
So the training is “stop the threat”, be prepared to shoot 5 rounds center mass as quickly as possible, move, maintain a sight picture, do all the things you need to do but focus on the target first and gun and number of bullets second.