I taught Use of Force at a regional police academy. There is no such thing as shoot to kill or shoot to wound. The only time a police officer is justified to use deadly force is when they have no other option to make a subject(s) cease their actions, such actions that have, or may be reasonable to assume will, cause death or serious injury to the officer or another person.

The officer doesn't have to be hit over the head with a baseball bat to know that such action will cause death or serious injury, he/she can take whatever actions, including deadly force, are necessary to compel/force the subject to cease their actions. If the subject dies as a result of the officer's actions, that it a consequence, not an intended result, of the officer's use of deadly force.

There have been cases, described by Mas Ayoob and others, questioning the type of weapon used in a deadly encounter, and in one case in particular, an individual was convicted based on the weapon he used to defend himself, i.e. intent to cause death/bodily injury due to the "stopping power" of the weapon.

I have always advocated to use what the police use. There are plenty of good weapons and ammunition that will be sufficient for self/home defense. It is difficult for a prosecutor to show "evil intent" when you are carrying the same weapon and load that the FBI, Secret Service, local sheriff, police, etc., carry.