Let's shift the conversation a bit, leaving aside for a minute your other expressed views on self-defense. Let's talk about sample selection bias:
1. My wife is a child psychiatrist. She treats kids with autism a lot. Sometimes one of my kids behaves in ways that disturb me, but my wife tells me, "that's fairly common behavior." But that's "common among the kids who are seeing psychiatrists" which is not at all the same as common among kids in general. What she means is, "that's common enough in the autistic population and I see it enough times to know that it's not concerning in itself," and I know that. She doesn't have to say that whole mouthful every time. But if you were to hear her, you might take the wrong conclusion away. And in addition, sometimes she fools herself: after a long day, she can be drained and maybe she says, "that's common" when she means "I see it frequently."
2. I have never witnessed a murder or been on a crime scene when a murder is created. So my baseline experience in the world is "no homicides." Obviously I know they exist; but I'm naturally conditioned to see them as very rare. Which they are, depending on what is meant by "very." But "very" is the issue under dispute, right? So my experience biases me toward believing undercounts.
3. You're an emergency responder, both fire and EMT, IIRC. Well, nobody calls the EMT when they have an argument and settle the matter peacefully. Nor is EMT called if there's a burglary where the intruder takes a few things and leaves. You get called when there is blood on the floor. So naturally you are experientially conditioned in a different way than me, perhaps almost opposite. So you are prone to believing overcounts.
The way to address sample selection biases is to 1) be aware of them; and 2) try to correct for them. This is why I always read primary sources rather than rely on news reports, where possible. The primary source presents the information raw, and I can evaluate. Sometimes, if the subject is technical, I have to work with secondary sources that explain things, but I always try to verify as close to the information as possible. And because I'm aware of my bias (not only on this issue), I try hard to minimize that effect. I doubt I succeed 100%, but I think I'm pretty good at it.
You might have noticed that sometimes I defend posters I'm arguing against from attacks that I see as unfounded. I don't want to knock down strawmen. I want to get to the truth. So if I'm criticizing someone because they are saying A and A isn't true, and some other poster accuses that person of saying B, when they weren't saying that, I often respond against B. I say, "in fairness, he's not saying B; he's saying A." "In fairness to [poster]" is probably one of those phrases I type more than any other poster.
4. Is it possible you believe what you do about gun violence because of what you do and it biases you toward a more dystopian view than is warranted?