Most states–at last count, 39–are “shall issue” states. In other words, if you meet the criteria for concealed carry under the law, no public official may deny you a license. Illinois was the only state where concealed carry was absolutely prohibited, but recent court orders have drug the legislature and Chicago political machine kicking and screaming into new and at least tentative compliance with the Second Amendment, though that battle goes one.
Andrew Branca definitive book, The Law of Self Defense, is a must reading for anyone concerned about these issues and adds several other related criteria/concerns:
Innocence: the defender must not be the initial or unlawful aggressor. People engaging in mutual combat can’t claim innocence. They’re not engaging in self-defense.
Imminence: this is another way of expressing the concept of jeopardy. One can’t use deadly force against an attack that might happen at some time in the future. The danger must be real, clearly about to occur–within fractions of a second or seconds, or already occurring.
Proportionality: the threat can’t be humiliation or minor injury. If the only thing in jeopardy is hurt feelings, even a punch in the nose might not be proportional. A reasonable person must believe he or she is facing a threat of serious “grave” or bodily harm.
Reasonableness: A reasonable person of the same knowledge, abilities and in the same circumstances would be compelled to use deadly force.
State laws vary, using different terms, and it is everyone’s responsibility to be aware of the law in their state of residence. Some states particularly allow the use of force–even deadly force–under circumstances where others do not. What this basically means is that in any situation in which a reasonable person would believe that they–or another–was faced with the imminent–as opposed to possible or future–threat of serious bodily injury or death, deadly force is a reasonable response.
Of course, running away might also be a wise and reasonable response, but only if it is reasonably possible. In states that have enacted the Castle Doctrine or a “stand your ground” law–more about that later–it is not required, but it may still be a good idea.
It’s important to understand what “serious bodily injury” means. While the legal definition will tend to vary somewhat from state to state, it essentially refers to injury that, while not deadly, is crippling, seriously disfiguring; one that will have a continuing, negative impact on the quality and longevity of your life from the moment it is inflicted…
Gunshot wounds are ugly, nasty and can be permanently debilitating. Equally, cuts inflicted by edged weapons like swords or knives can be as debilitating and in many ways, far more horrific and ugly. Many police officers that survive a gunshot wound may be physically healed, but never fully recover psychologically. Broken bones from a beating would also certainly qualify. The greatest problem is how do you know what injury the next blow delivered by hand or foot will cause? Will you be merely bruised? Will bones be shattered? Will you be blinded, brain damaged, crippled, even killed?
…The means for determining–on the spot–if deadly force is necessary and justified is to apply the “means, opportunity, and jeopardy” test. Keep in mind that this explanation assumes that you are the innocent party; you have not provoked or initiated the confrontation. It also assumes that a reasonable person of the same abilities in the same circumstances would be compelled to apply deadly force. There are a variety of similar terms/acronyms, but they all boil down to the same thing:
Means: Does your opponent have the means necessary to cause serious bodily injury or death? If you are a 100 pound, five-foot woman, any man of average size and strength would almost certainly have the means necessary to cause serious bodily injury employing only his bare hands–if he is close enough. Someone with a gun certainly would. Someone with a knife, almost certainly, and someone holding a variety of other instruments would also pose such a threat. Someone known to be highly skilled in a martial art, even if he or she is smaller than you, might also have the means.
Opportunity: Does your opponent have the opportunity to cause serious bodily injury or death? An attacker armed with a handgun certainly does…, perhaps as much as 50 yards away, although there is always such a thing as a lucky shot even at greater ranges. An attacker armed with a rifle has a much greater dangerous range. Someone armed with a knife is dangerous to a minimum of 21 feet, perhaps even more, as practical experience demonstrates that even an average person with a knife can move 21 feet before he or she can be shot and/or stopped by a handgun-wielding victim. Practicing for this possibility is commonly known as the Tueller Drill…
If a knife-wielding opponent (at a greater than 21-foot distance) appears as though he or she will throw the knife, a reasonable person must assume that the attacker can cause serious injury or death at a distance with that knife. Other tools such as hammers, bats, screwdrivers, etc. are also dangerous if the person wielding them is close enough and, arguably, throw them from a reasonably close distance…
Jeopardy: is an attacker acting in such a way as to indicate to a reasonable person that he or she might be in imminent danger of serious bodily injury or death? …Someone standing across the street with a knife yelling threats is not putting you in jeopardy, but when they begin to run toward you, jeopardy increases enormously with each foot gained…
Shooting to Kill: YOU MUST NEVER SAY, OR EVEN THINK, THAT YOU SHOOT TO KILL. You never shoot unless the requirements for means, opportunity, and jeopardy test have been satisfied… You shoot only to STOP the attacker from putting you in imminent danger of serious bodily injury or death. To that end, you shoot as quickly and effectively as possible to immediately end the threat.
This might seem to be an exercise in semantics, but it is very important. If being investigated (or on trial for shooting another human being) regardless of how innocent you are and how reasonable and correct your actions, every word you utter and every intention you purport to have had will be vital to your freedom and future.
With that in mind, one shoots to stop an attacker, not because you wanted to kill someone but because you had no choice; because if you didn’t stop the attacker, you would have been seriously injured or killed. That they died as a result of being stopped is regrettable and a tragedy, but a tragedy they forced on you, an innocent person who had no intention of hurting them or anyone else. You are the innocent victim of a deadly attack, and you must say and do nothing to paint yourself as anything but an innocent, remorseful victim.