Where am I lacking?
To use deadly force there must be a threat.
Yes, there has to be a threat (Ability, opportunity, intent). I talked about it in a previous thread. But that's just the beginning. Is a 6ft 210 22 yr old male a threat? If so, what Level of force can you use today, in Marion County. What about tomorrow after leaving the dentist office from a root canal in Hendricks county? Is a 12 yr old who walks up to you with his hands in his pockets and says give me your wallet or I will kill you a threat? What force can you use against him? A man runs at you with a ball bat yelling profanity? Can you use deadly force? What if he drops the bat 6 feet from you but continues at a full sprint? Can you shoot? Why or why not?
Do the same principals apply to an off duty police officer? What about a 50 year old woman? When do you have a duty to refrain from using force? What if I am not the one being attacked, but witness 2 guys fighting in the parking lot just as one gets mount and shoots the other one?
This is just barely scratching he surface of one aspect,,THREAT, but you get the point. Like I said, use of force s RARELY black and white.
Learning how to run a gun i the easy part. There's probably 50 instructors on here alone who can teach that. It's the gray areas that most are untrained in.