A very simple debunk for the "Good-guy-with-a-gun"-myth:

[DetlefK]

Hi.

I'm a good guy.

This is my gun.

I'm a good guy with a gun.

Bang, you are dead.

Now I'm a bad guy with a gun.

How come no good guy with a gun showed up to stop me?

[PJMcK]

1. It's easier

Uvalde.

That is all.

[hunter]

2. The more common story is:

I'm a good guy. This is my gun.

Bang. Now good guy is dead.

[lame54]

3. Because they were busy tasering good guys without guns

[Thomas Hurt]

4. or...

good guy with a gun.

Bad guy shows up with a gun

Bad guy starts killing people

Cops show up, can't tell bad guy from good guy

Good guy dies in a hail of bullets.

or...

good guy with a gun.

Bad guy shows with a gun

Bad guy starts killing people

Good guy with gun dives for cover as he soils himself.

[Frasier Balzov]

5. Truth.

https://www.denverpost.com/2021/06/27/arvada-shooting-guns-self-defense/