Would a civilian be able to claim that?
Is assisted suicide now acceptable?
You mean citizen? Police are civilians, and yes, absolutely. Especially with Stand Your Ground.
Assisted suicide? That takes two willing parties; the police weren’t willing in this case but were forced to. That kid knew they would shoot him and he found out in the last seconds of his life that it hurt as well.
Let me leave you with this. That kid told others that he was suicidal long before this happened. No one did anything until he forced the police to do something. Suicidal people talk about their plans, you just have to be listening.