This will hinge upon the father knowing or not knowing the boyfriend had a key and whether or not the boy was a "houseguest" of the daughter given that the car was purportedly at the house all day. We are ALL making assumptions here but if I was investigating, here is what I'd want to know: was the boy a guest of the daughter at any time during the day? was the father aware of this (if knew there were house guests, then shoot-first becomes questionable)? if a guest, did the daughter and boy lead the father to believe the boy had gone home? did the daughter arrange for the boy to come back after dad was asleep? what will the boy's tox screen show? If he was under the influence, then opening a door with a key can sound much like someone breaking in. Who gave the boy the key? did the father know he had one? Until a lot of questions are answered, this cannot be called a righteous shoot.
And anyone questioning young punks in the greater Miami area driving late model expensive cars just hasn't been keeping up. Jeez.