Jusy my $.02 cents, but Massad Ayoob, if you're familiar with him, suggests a procedure if you're involved in a self-defense shooting. He suggests saying several things when police arrive.

Given the respect a lot of people have for him, and that he is police officer, I think it might be worth a look. His idea is to establish that you were defending yourself against an attack and to point out any evidence--shell casings, witnesses, surveillance cams. Then, you say that you want to speak to a lawyer before you go any further.