I would incline toward Manslaughter.
The problem here is that he was not surprised by the burglars but knew they were coming and was luring them in by making it look like no one was home all the while watching on his live video.
It’s one thing to then detain them, to tie them up, even shoot them if they don’t cooperate or threaten you, but what the prosecution is showing is that he wanted them to come in so that he could kill them and then claim self defense.