[Erik]

What to do to maximize the chances of being ID'd as a/the good guy on a firearms related call, be it a shooting or other wise, is a good thing to know.

Unfortunately, it is a complicated thing at times, with no clear cut solutions.

The simple answer is: Do not appear to be a threat.

But how? I'll explain my take on it, in order:

Prior to LEOs arrivig on scene:

Call 911. The advise to call with details and descriptions is sound. Try to inform dispatch of injuries to yourself and others which will have to be treated.

Get the gun out of your hand. Holster it, drop it, place it somewhere, whatever.

Keep your hands visible. Raised, out, at your side, it doesn't matter, so long as they are visible.

Unfortunately, situations being what they are, you shouldn't count on being able to that. Phone calls can't be made, guns have to be in hand, and hands cannot always be displayed as imagined.

Which means the plan about what to do when the LEOs arrive and find you gun in hand has to look like this: Do not appear to be a threat.

If you were able to make that 911 call you should still ideally be on the line. Use that to your advantage, re-iterating your location and description and talking the LEOs in to the dispatcher.

Get the gun out of your hand. Holster it, place it on something, or drop it, whatever. Slowly. Deliberately.

Keep your hands visible.

Now the LEOs are on scene, as in out of cars, guns drawn, looking at you and possibly pointing their guns at you.

Do not assume. Do not assume they know you are a LEO. Do not assume they recognize you. Do not assume you are obviously the good guy.

Comply. Immediately. Period.

Don't move. When directed to move, do so slowely and deliberately.

Don't turn toward the LEOs if you still have a gun in your hand. It is the only exception to the comply immediately rule. I've actually seen this: a LEO, not realizing a third party was armed with gun in hand, command the man to turn followed not by movement but a calm question about what to do with the gun first. It may have gone badly had the man turned. A very heads-up move on the part of the carrier, by the way.

Talk. Relay immediately critical information and that you're the good guy. IDing soemone as a/the good guy is easier with information to make the decision with. And LEOs really are much more interested in the bad guys. (I'm not saying to forget your rights. I'm talking about briefly IDing what happened, who and where the bad guys is, and that you aren't the bad guy.)

Expect things. Expect things will be tense. Expect guns will be pointed at you. Expect to be man-handled a bit. Expect to be handcuffed. Expect to be detained. That way you're prepared in advance and should any of that happen your body language will reflect your preperation and acceptance. When those things don't happen, even better. But remember, the main idea is for other things not to happen, like you getting shot.

Anyway, that's it off of the cuff. The risk cannot be elliminated, but it can be managed.