There are a very few squeaky clean cops here and there—real goody-two-shoes, “lone rangers,” some of them working for the fed, others not—who fire as everyone else does with groups on ranges but more accurately. Outside of that, those few do make sure that they can hit attackers in other, less conventional but very effective places very quickly and consistently, day or night. Everyone should strive for moral impeccability in relations with others. It’s best in the long run.
The gun is not used unless the life of the officer or the life of another person is in danger. It is therefore not fired unless deadly force is reasoned. You never fire to wound. If the person is a threat, he or she is armed. A wounding shot to the leg or arm would allow them to get off a shot. That shot could end someone’s life. If they have a weapon other than a gun, the same rule applies.
As for being accurate, police departments demand their officers go to the range and accomplish certain minimal scores to remain active on the force.
If I’m a police officer, I don’t want another officer being on the street with me, that would not be able to stop someone trying to kill me. My life depends on their ability to shoot accurately. Their life would depend on me being able to shoot accurately.