Very good points Rich. Paper does not shoot back and stands still waiting to be shot.

If you are going to carry a firearm it is your responsibility to know the rules.

The first place to start is your state law. There is no excuse for not knowing the laws. They are available at any library and on line.

Next there may by local laws and ordinances, check those out too.

If you use a firearm on someone or someone's animal, you may conceivably be clear of criminal liability, but can still be sued civilly. In civil court the burden of proof is only a preponderance of the evidence. The plaintiff only needs to prove their case 51 percent to prevail. Legal costs and damages, should you lose, can be astronomical.

The criminal codes often define terms like "reasonable force" "necessary force" etc. Your actions, motivations and everything else will be scrutinized in court later and these definitions and the laws will be held up against the actions that you took. Decisions in lethal force situations are often made in a split second. There is usually little or no time to ponder complex issues in a lethal force situation. There is no time for moral weighing if you want to prevail in defending yourself. You will be judged by people sitting in comfortable offices and courtrooms months or years later. They will have all the time in the world to consult law books, case studies and examine what you did or didn't do in that cold and lonely place where someone was trying to kill you.

Trained law enforcement officers have to regularly qualify with their weapons and be well versed in state law and their department policy. When they survive lethal force encounters they often don't even remember the specifics of their actions (like reloading their weapon under stress), but they fell back on their training during the incident. Their actions were autonomic due to constant practice and repetition. Attorneys for the plaintiffs often attempt to attack the officer's credibility on these issues. The officers must be cleared of criminal, civil and departmental scrutiny. If you choose to arm yourself, you must be well trained in the legal aspects of using force as well as the proper and proficient use of the weapon.

There are many private vendors who can and will provide this training to the private citizen. These courses are costly and some are better than others. Check references and do research. If you can document your training it might be helpful in later legal proceedings should you ever be in the position where you must use your weapon.

Some may ask, "Why a gun?" The answer is that it is not the universal answer. That is why the police have other force options like impact weapons, OC spray, Tasers, control holds and verbal commands. In a violent potentially lethal attack the goal of the victim should be to incapacitate (not kill, but that is often a side effect) the attacker as soon as possible to stop the attack. The quickest way to incapacitate a highly motivated attacker is to disrupt the brain function with a piece of lead moving at a high enough velocity to enter the cranial vault. Short of that you are in the position of waiting for the attacker's blood pressure to drop significantly from wounds or for them to make the mental decision to give up after feeling the pain of a lesser force option. There are many documented cases of suspects killing people after being mortally wounded, thus the need for quick incapacitation.

I believe very strongly that law abiding citizens have the natural right to defend themselves and others from criminal attack or from animal attack. There is nothing morally wrong with defending yourself and no government should interfere with that right. With this right comes great responsibility for which you will be held accountable.

Disclaimer
This is just an opinion and personal observations, not legal advice. I am not an attorney. If you have specific questions about legality, consult the laws and talk to an attorney.