"I'm not sure "arrested" is accurate. I think (from reading about many of those cases) the Cops will detain you for questioning"
I'm probably nit pik-ing here but any time you are handcuffed and detained, I'd call that an arrest.
Charges are a different issue, but that is what an arraignment is for.
The first words out of my mouth would be;
Am I being detained?
Am I free to go?
If I'm being detained and I'm not free to go, it is request a lawyer time.
and quit talking.
That is an arrest of your freedom to go about your business.
Alec caused a death and that has to be answered.
Purposeful, poor judgement, or accidentally.
The explanation must be a matter of public record.
Not a "Wink, wink, Nod, nod".
I wouldn't go with the annoying "Am I being detained, or am I free to go?" tirade. I'd just tell them I'm willing to cooperate and answer all of their questions, but I'd like to consult my attorney and have them present before I say anything.
If you already gave them a vague statement, like "This stranger threatened me with that knife, and I shot him in self defense," that's all you need to say at the scene. Save the details for when your lawyer gets with you.
If you just shot someone, I don't think saying "Am I being detained?" is a very intelligent question for you to ask!