Advice from Mas Ayoob on what to say in such an instance.
1. That person attacked me
2. There is the evidence (point out spent shell casings, dropped weapon, etc)
3. Those people saw what happened (point out witnesses )
4. Officer, I'm sure you understand the gravity of this situation. You will have my full cooperation in 24 hours after I have had a chance to discuss with counsel.
Best advise for these situations.