Re: Legal or Not?
The law enforcement standard, at least in our department, is described by the Ability, Opportunity, Jeopardy standard.
There are some additional flavors which include Preclusion, but the AOJ standard is pretty widely-recognized.
I copied the text below from a Web site that enunciated AOJ pretty well and am reposting it. There are different ways of describing it, but this one is pretty good.
Ability
The other person in question has the power to cause you death or great bodily injury. The concept of death is pretty self-explanatory. But what of great bodily injury? This could be open to interpretation. It could mean losing a limb. It could mean paralysis. It could mean any kind of harm that might possibly affect your physical abilities until the end of your life: crippling physical injury. Weapons are certainly a great equalizer and can come into play here. Disparity of force is also an important consideration: what if you were unevenly matched against the threat? Examples of this might include: a bigger and stronger person versus a smaller and weaker person, multiple attackers versus one individual, a man versus a woman, a skilled martial arts practitioner versus an unskilled opponent, an able-bodied individual versus one who has physical disabilities, an adult versus a child, etc.
Opportunity
Does the other person have the opportunity to maim or kill you at this very moment? How far away is he or she? Are there obstacles in the way of this person doing you harm? It is important whether the other person is armed or not, as well. Obviously, if someone has produced a firearm and is within sight of you, this certainly presents a good opportunity for them to harm you. If that person is wielding a knife or other improvised weapon and they are 50 meters away, it’s not justifiable to gun them down! However, if this person is an able-bodied adult within 21 feet of you, he or she can cover that distance within about 1.5 seconds. That changes the game considerably! You must use common sense and observe the pertinent environmental variables.
Jeopardy
This means the threat is immediate. The totality of the situation indicates to you that you or a third party is in grave danger, here and now. This is where reasonableness really comes into play. Perhaps this individual did not verbally indicate the intent for facilitating your early demise, but was advancing toward you menacingly in your home and with a weapon drawn. Do you stand there and wait for confirmation? Certainly not! Perhaps this individual does state the intention to kill you, and has the ability to do so, but no opportunity. This is important because the threat is not actually imminent. As soon as opportunity does exist, it can change to imminent danger in a heartbeat!
Keep in mind that your own jurisdiction, state, locality, State's Attorney, Law Enforcement Agencies, etc. will all have slightly different standards for how any standard is enforced or prosecuted and, like it or not, your local media will have a role as well. Nothing is cut and dried.
Soooo. the advice above that folks above have given you is generally good (well, except the cat suit... though that cracked me up!) Yell, call 911, flee if you can... etc. etc. etc.
To expand on a post above: If you shoot someone under virtually any circumstance, you will be arrested. You will go to court at least for an arraignment while decisions as to whether to charge you are made. You may end up in a trial. If the court decides not to prosecute you for criminal violations, some halfwit relative of the person you shot will turn up and sue you for violating their relative's rights... and if you leave the person paralyzed or badly injured... they will sue you eight ways from Sunday! And by the time they get to court, the perp will be all squeaky clean looking, wearing a suit and fresh from Baptism. No matter what, you will have huge legal fees, etc. even if you come out on the right side of things.
Remember that even an officer involved in a shooting gets put on leave and goes through the ringer. And is subject to the same civil suits, etc. It's not like TV!
Finally, I'm not an attorney, just a simple small-town LE. But I would say that self defense in an arms-length, alley-way or bedroom encounter can appear relatively clear cut under the AOJ standard. However, a long range engagement with high-powered rifles is going to be really, really hard to justify under any reasonable standard. I don't think it would go well for you or anyone else under those circumstances.
Just my $0.02... the usual caveats apply.
Cheers,
Sirhr