Know the laws of self defense where you are. If you use force in defense of yourself or others and the person is injured, of course call 911 and get medical assistance. The 911 dispatcher will ask a lot of questions to pass on to responding officers, and everything said is recorded and admissible. Do not have your weapon out when LE arrives. Any excited utterances are admissible. Do not argue with or antagonize responding officers. Be polite and tell them you will be happy to talk to them with your attorney present. They will take your gun. They may even put you in cuffs while they investigate. If you have any inkling that you may use a firearm for defensive purposes, you really should have a legal insurance policy like U.S. Law Shield, U.S. Concealed Carry, NRA, etc. I have a 24/7 number in my wallet to call if needed. Even when you are in the right, defending yourself from an overzealous charge can cost you many thousands in legal fees. One thing to consider. The decision to arrest you for a crime is based upon probable cause. Probable cause is initially determined by responding officers. Some officers responding to shootings will arrive with preconceived notions that may not be in your favor. It is in your best interest to have those notions dispelled as quickly as possible.