Preface-- I am not an attorney. I am a Use of Force instructor. Don't construe this as legal advice.
It might surprise you, but I don't teach SD legalities as a decision making course. Truth is, things are likely to happen very fast, in a fog of adrenaline, and with limited visibility and information. That said, almost everyone makes good, legal decisions. For the most part, self-defense laws (like any laws) are simply a codification of standard morality. You were raised in this culture. If you aren't a pathological asshole, your instincts will be in line with the law.
I only see three places (overzealous prosecutors aside) where normal people get in trouble with claiming self-defence:
- A monkey dance, where two usually stupid and drunk young men insist a mutual fight was self defense because the other guy started it. (one stared, so he started it, the other said something so he started it, one pushed so he started it, the other swung so he started it...)
- The incident is over, the threat either down or fleeing, and you want to teach him a lesson.
- You have been trained to do something, like cut the throat on a downed threat, as part of the technique. You could be on the hook criminally and civilly, your instructor might be facing civil liability.
You don't want to hurt anybody unless you have to, right? You don't want to hurt them more than you need to, right? You don't want to kill anybody unless it is the only way to save an innocent life, right? If you answered yes to all three, congratulations. Your instincts are in line with the law.
But here's the problem-- you can do the right thing and tell the story badly.
Imagine a cliche victim of spousal abuse. Tiny, terrorized. He's threatened to kill her and recently put his handgun against her head and laughed. He's big, strong and unpredictably violent. Over dinner, he played a round of russian roulette with her head and when she asked about the children he said if she lost the game he'd just kill the children, too, and leave town...
So that night, while he is in a drunken stupor, she shoots him.
As SD, this is beyond iffy. Why didn't she leave? Why didn't she get the authorities involved?
If she said, "I couldn't run. I've tried before and he always found me. I was in the hospital for four days last time. And he said if I ever called the cops, he'd just post bail and take it out on one of the kids. He was bigger and stronger and I was terrified but it was the only chance I had, the only chance the kids had."
However if she said, "I wasn't going to put up with his shit anymore. So I crept up on him while the fat pig was snoring and put one in his brain. Bastard had it coming." What reaction would the jury have?
Get this: Both of these accounts fit the (imaginary) facts of the case. They are 'true' in that sense. A bigger, stronger, violent man with resources to get out of jail and no qualms about hurting children is a bastard who has it coming.
One of the things you must understand is that criminals practice lying to cops. Have you ever, in your life, practiced telling the truth to the cops? If not, what are the odds you will be good at it? Too often a skillful lie will trump a clumsy truth. That's one of the reasons you want an attorney. Their job is to present the story properly.
Aside-- Don't take story to mean fiction. Never lie. For both moral and practical reasons, lying doesn't serve you. When I say story, I mean that people are wired to understand things in narrative form, and they get nuance of meaning from word choice. The Jack Webb "just the facts. ma'am" is great for investigation, but if you're describing the most terrifying minute of your life in cold and robotic terms, you sound non-human. And people, whether they be cops, investigators, prosecutors or a jury are never just evaluating your actions. Consciously or not, they are evaluating you.
There are elements of a self-defense claim. You have to explain the source of your fear, why you couldn't leave, why a lesser force would have failed. Most importantly, how every bad decision that led to the moment was made by the bad guy. Again, instinctively you will have done almost all of this. But, especially under the wash of adrenaline, you might not have been aware of it or remember it now. The part of your brain that thinks in words is a very tiny part of your thinking power, but the whole brain is very good at what it does. Trust your own brain.
There are exercises to work on consciously explaining and understanding subconscious decisions. I've written about it before, and this is getting long.
That's what you say. There are two more elements (at least) to a good self-defense claim. When do you say it? Who says it?
When? Any good attorney will give you advice to not talk to the police at all. Good advice but very hard to pull off without looking very guilty, and the officers will play on that appearance of guilt to get you to talk. Especially hard because people tend to babble under stress and you will be under stress. And babbling implies what you think it does. Much of what you say will not be accurate.
There are four basic times when you will be asked for your story:
- Cops at the scene will ask what happened. There are different options. Say nothing. Or point out witnesses, evidence and no more. Or say that you aren't calming down and want to see a doctor. Or say that one of your friends is a lawyer and he told you to call him if police were involved in anything and that's what you should do or... Mine? I'll say, "Gentleman, you're doing your job and I want to help but I've heard horror stories about what can happen in civil cases. I'll cooperate fully as soon as my attorney gets here."
- If the incident resulted in death or serious injury, detectives will want to question you. Demand an attorney. Make no statements until he or she arrives.
- The meeting with your attorney. Get a good attorney. Tell the attorney everything.
- This doesn't count as one of the four, but there may be depositions and motion hearings and all the things you pay your attorney to guide.
- The trial
Who tells the story? When possible, I prefer the witnesses or the video to tell the story. Adrenaline can distort your memory and probably did distort your perception, and anything you missed might be characterized as a lie to challenge your credibility. Within this story you, with the help of your attorney, you can add commentary ("That was when I realized he'd cut off my only escape.")
When that's not an option (a skilled predator will do his best to make sure there are no witnesses or video) it's up to you. With your attorney's guidance. In a jury trial, whether to take the stand yourself is a tactical decision. If you don't present well, if you get flustered, if you come across as too cold or are easy to provoke, it's probably best NOT to take the stand.
Again, you can be 100% right, have all the facts on your side, and torpedo yourself with a poor articulation. Articulation is a learnable, trainable skill.