On the one hand, I strongly recommend In the Gravest Extreme.
On the other hand, Mas does NOT recommend using cliche lines such as "I was in fear for my life." He says that has become such a catch-phrase that it will almost immediately sound rehearsed to the investigators.
What Mas recommends is the following outline:
1) Explain the basic dynamic, identifying yourself as victim and the other guy as aggressor. "He came at me with a weapon."
2) State your willingness to sign a criminal complaint, further cementing your status as victim.
3) Point out any witnesses, before they can leave the scene.
4) Point out any evidence, before it magically disappears. (Mas told us about one case where an ambulance crew member kicked the attacker's gun out of his way, when he was treating the downed attacker... cops didn't find the gun, and thought the victim/shooter was lying to them... he also told us that at the 1986 Miami shootout, souvenir hunters were observed stealing spent casings while officers were on scene.)
5) Once you've done that, say you will assist the investigation and make a further statement after discussing it with counsel.
As noted, do NOT talk to the press, or, for that matter, post details of your encounter on an internet forum.
Mas also said don't just "keep your mouth shut." First, because that is what perps do, and the signal the officers will get is that you have something to hide. Second, because their initial impression will affect how they approach the investigation. And third, because witnesses and evidence can disappear, or just be overlooked.
