My rules:
Never point a weapon at something you are not prepared to kill.
Never just display a weapon as an legally unjustified threat. That is the crime of "assault."
If you ever use a weapon, remember who the witnesses were, and who they weren't. In the Michael Brown shooting, there were multiple so-called witnesses who started the "Hands Up - Don't Shoot" rumors and who were later proven to not be witnesses to anything. Point out the witnesses, or lack of them to arriving LEOs. Likewise, if perp shot at you and hit a target that might be later moves, such as a car, point that out to LEOs as well.
If the perp had a weapon, ensure no co-conspirator of his removes it from the scene.
Other than that, identify yourself to the LEO, and then direct all, I repeat ALL LEO question to your lawyer.
One of my many CCW rules:
When you strap the gun on, leave your ego at home.
"...Commandment IV..."
M4L. Massad
An excellent set of commandments. I’m going to cut, paste, print it out so I can memorize them.
CCW BUMP