It doesn't matter who is on the other side, if you introduce a gun into a situation, you better be ready and able to kill someone. The cops suck, no doubt, and this man had every right to come to the door armed, but rights never stopped a single bullet in flight. Cameras are neccessary, and they are cheap and easy these days. If he knew they were standing there, he could have handled this without dying. If you point a gun at someone with a gun, the person willing to pull the trigger first will almost always live to tell the tale. There is what is right and there is reality.